ld64-409.12.tar.gz

[apple/ld64.git] / src / ld / OutputFile.cpp

/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-*
 *
 * Copyright (c) 2009-2011 Apple Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/sysctl.h>
#include <sys/param.h>
#include <sys/mount.h>
#include <fcntl.h>
#include <errno.h>
#include <limits.h>
#include <unistd.h>
#include <mach/mach_time.h>
#include <mach/vm_statistics.h>
#include <mach/mach_init.h>
#include <mach/mach_host.h>
#include <uuid/uuid.h>
#include <dlfcn.h>
#include <mach-o/dyld.h>
#include <mach-o/fat.h>

#include <string>
#include <map>
#include <set>
#include <string>
#include <vector>
#include <list>
#include <algorithm>
#include <unordered_set>
#include <utility>
#include <iostream>
#include <fstream>

#include <CommonCrypto/CommonDigest.h>
#include <AvailabilityMacros.h>

#include "MachOTrie.hpp"

#include "Options.h"

#include "OutputFile.h"
#include "Architectures.hpp"
#include "HeaderAndLoadCommands.hpp"
#include "LinkEdit.hpp"
#include "LinkEditClassic.hpp"

namespace ld {
namespace tool {

uint32_t sAdrpNA = 0;
uint32_t sAdrpNoped = 0;
uint32_t sAdrpNotNoped = 0;


OutputFile::OutputFile(const Options& opts) 
	:
		usesWeakExternalSymbols(false), overridesWeakExternalSymbols(false), 
		_noReExportedDylibs(false), pieDisabled(false), hasDataInCode(false), 
		headerAndLoadCommandsSection(NULL),
		rebaseSection(NULL), bindingSection(NULL), weakBindingSection(NULL), 
		lazyBindingSection(NULL), exportSection(NULL), 
		splitSegInfoSection(NULL), functionStartsSection(NULL), 
		dataInCodeSection(NULL), optimizationHintsSection(NULL),
		symbolTableSection(NULL), stringPoolSection(NULL), 
		localRelocationsSection(NULL), externalRelocationsSection(NULL), 
		sectionRelocationsSection(NULL), 
		indirectSymbolTableSection(NULL),
		threadedPageStartsSection(NULL),
		_options(opts),
		_hasDyldInfo(opts.makeCompressedDyldInfo()),
		_hasThreadedPageStarts(opts.makeThreadedStartsSection()),
		_hasSymbolTable(true),
		_hasSectionRelocations(opts.outputKind() == Options::kObjectFile),
		_hasSplitSegInfo(opts.sharedRegionEligible()),
		_hasFunctionStartsInfo(opts.addFunctionStarts()),
		_hasDataInCodeInfo(opts.addDataInCodeInfo()),
		_hasDynamicSymbolTable(true),
		_hasLocalRelocations(!opts.makeCompressedDyldInfo() && !opts.makeThreadedStartsSection()),
		_hasExternalRelocations(!opts.makeCompressedDyldInfo() && !opts.makeThreadedStartsSection()),
		_hasOptimizationHints(opts.outputKind() == Options::kObjectFile),
		_encryptedTEXTstartOffset(0),
		_encryptedTEXTendOffset(0),
		_localSymbolsStartIndex(0),
		_localSymbolsCount(0),
		_globalSymbolsStartIndex(0),
		_globalSymbolsCount(0),
		_importSymbolsStartIndex(0),
		_importSymbolsCount(0),
		_sectionsRelocationsAtom(NULL),
		_localRelocsAtom(NULL),
		_externalRelocsAtom(NULL),
		_symbolTableAtom(NULL),
		_indirectSymbolTableAtom(NULL),
		_rebasingInfoAtom(NULL),
		_bindingInfoAtom(NULL),
		_lazyBindingInfoAtom(NULL),
		_weakBindingInfoAtom(NULL),
		_exportInfoAtom(NULL),
		_splitSegInfoAtom(NULL),
		_functionStartsAtom(NULL),
		_dataInCodeAtom(NULL),
		_optimizationHintsAtom(NULL)
{
}

void OutputFile::dumpAtomsBySection(ld::Internal& state, bool printAtoms)
{
	fprintf(stderr, "SORTED:\n");
	for (std::vector<ld::Internal::FinalSection*>::iterator it = state.sections.begin(); it != state.sections.end(); ++it) {
		fprintf(stderr, "final section %p %s/%s %s start addr=0x%08llX, size=0x%08llX, alignment=%02d, fileOffset=0x%08llX\n", 
				(*it), (*it)->segmentName(), (*it)->sectionName(), (*it)->isSectionHidden() ? "(hidden)" : "", 
				(*it)->address, (*it)->size, (*it)->alignment, (*it)->fileOffset);
		if ( printAtoms ) {
			std::vector<const ld::Atom*>& atoms = (*it)->atoms;
			for (std::vector<const ld::Atom*>::iterator ait = atoms.begin(); ait != atoms.end(); ++ait) {
				fprintf(stderr, "   %p (0x%04llX) %s\n", *ait, (*ait)->size(), (*ait)->name());
			}
		}
	}
	fprintf(stderr, "DYLIBS:\n");
	for (std::vector<ld::dylib::File*>::iterator it=state.dylibs.begin(); it != state.dylibs.end(); ++it )
		fprintf(stderr, "  %s\n", (*it)->installPath());
}	

void OutputFile::write(ld::Internal& state)
{
	this->buildDylibOrdinalMapping(state);
	this->addLoadCommands(state);
	this->addLinkEdit(state);
	state.setSectionSizesAndAlignments();
	this->setLoadCommandsPadding(state);
	_fileSize = state.assignFileOffsets();
	this->assignAtomAddresses(state);
	this->synthesizeDebugNotes(state);
	this->buildSymbolTable(state);
	this->generateLinkEditInfo(state);
	if ( _options.sharedRegionEncodingV2() )
		this->makeSplitSegInfoV2(state);
	else
		this->makeSplitSegInfo(state);
	this->updateLINKEDITAddresses(state);
	//this->dumpAtomsBySection(state, false);
	this->writeOutputFile(state);
	this->writeMapFile(state);
	this->writeJSONEntry(state);
}

bool OutputFile::findSegment(ld::Internal& state, uint64_t addr, uint64_t* start, uint64_t* end, uint32_t* index)
{
	uint32_t segIndex = 0;
	ld::Internal::FinalSection* segFirstSection = NULL;
	ld::Internal::FinalSection* lastSection = NULL;
	for (std::vector<ld::Internal::FinalSection*>::iterator it = state.sections.begin(); it != state.sections.end(); ++it) {
		ld::Internal::FinalSection* sect = *it;
		if ( (segFirstSection == NULL ) || strcmp(segFirstSection->segmentName(), sect->segmentName()) != 0 ) {
			if ( segFirstSection != NULL ) {
				//fprintf(stderr, "findSegment(0x%llX) seg changed to %s\n", addr, sect->segmentName());
				if ( (addr >= segFirstSection->address) && (addr < lastSection->address+lastSection->size) ) {
					*start = segFirstSection->address;
					*end = lastSection->address+lastSection->size;
					*index = segIndex;
					return true;
				}
				++segIndex;
			}
			segFirstSection = sect;
		}
		lastSection = sect;
	}
	return false;
}


void OutputFile::assignAtomAddresses(ld::Internal& state)
{
	const bool log = false;
	if ( log ) fprintf(stderr, "assignAtomAddresses()\n");
	for (std::vector<ld::Internal::FinalSection*>::iterator sit = state.sections.begin(); sit != state.sections.end(); ++sit) {
		ld::Internal::FinalSection* sect = *sit;
		if ( log ) fprintf(stderr, "  section=%s/%s\n", sect->segmentName(), sect->sectionName());
		for (std::vector<const ld::Atom*>::iterator ait = sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
			const ld::Atom* atom = *ait;
			switch ( sect-> type() ) {
				case ld::Section::typeImportProxies:
					// want finalAddress() of all proxy atoms to be zero
					(const_cast<ld::Atom*>(atom))->setSectionStartAddress(0);
					break;
				case ld::Section::typeAbsoluteSymbols:
					// want finalAddress() of all absolute atoms to be value of abs symbol
					(const_cast<ld::Atom*>(atom))->setSectionStartAddress(0);
					break;
				case ld::Section::typeLinkEdit:
					// linkedit layout is assigned later
					break;
				default:
					(const_cast<ld::Atom*>(atom))->setSectionStartAddress(sect->address);
					if ( log ) fprintf(stderr, "    atom=%p, addr=0x%08llX, name=%s\n", atom, atom->finalAddress(), atom->name());
					break;
			}
		}
	}
}

void OutputFile::updateLINKEDITAddresses(ld::Internal& state)
{
	if ( _options.makeCompressedDyldInfo() ) {
		// build dylb rebasing info  
		assert(_rebasingInfoAtom != NULL);
		_rebasingInfoAtom->encode();
		
		// build dyld binding info  
		assert(_bindingInfoAtom != NULL);
		_bindingInfoAtom->encode();
		
		// build dyld lazy binding info  
		assert(_lazyBindingInfoAtom != NULL);
		_lazyBindingInfoAtom->encode();
		
		// build dyld weak binding info  
		assert(_weakBindingInfoAtom != NULL);
		_weakBindingInfoAtom->encode();
		
		// build dyld export info  
		assert(_exportInfoAtom != NULL);
		_exportInfoAtom->encode();
	}
	
	if ( _options.sharedRegionEligible() ) {
		// build split seg info  
		assert(_splitSegInfoAtom != NULL);
		_splitSegInfoAtom->encode();
	}

	if ( _options.addFunctionStarts() ) {
		// build function starts info  
		assert(_functionStartsAtom != NULL);
		_functionStartsAtom->encode();
	}

	if ( _options.addDataInCodeInfo() ) {
		// build data-in-code info  
		assert(_dataInCodeAtom != NULL);
		_dataInCodeAtom->encode();
	}
	
	if ( _hasOptimizationHints ) {
		// build linker-optimization-hint info  
		assert(_optimizationHintsAtom != NULL);
		_optimizationHintsAtom->encode();
	}
	
	// build classic symbol table
	assert(_symbolTableAtom != NULL);
	_symbolTableAtom->encode();
	assert(_indirectSymbolTableAtom != NULL);
	_indirectSymbolTableAtom->encode();

	// add relocations to .o files
	if ( _options.outputKind() == Options::kObjectFile ) {
		assert(_sectionsRelocationsAtom != NULL);
		_sectionsRelocationsAtom->encode();
	}

	if ( !_options.makeCompressedDyldInfo() && !_options.makeThreadedStartsSection() ) {
		// build external relocations 
		assert(_externalRelocsAtom != NULL);
		_externalRelocsAtom->encode();
		// build local relocations 
		assert(_localRelocsAtom != NULL);
		_localRelocsAtom->encode();
	}

	// update address and file offsets now that linkedit content has been generated
	uint64_t curLinkEditAddress = 0;
	uint64_t curLinkEditfileOffset = 0;
	for (std::vector<ld::Internal::FinalSection*>::iterator sit = state.sections.begin(); sit != state.sections.end(); ++sit) {
		ld::Internal::FinalSection* sect = *sit;
		if ( sect->type() != ld::Section::typeLinkEdit ) 
			continue;
		if ( curLinkEditAddress == 0 ) {
			curLinkEditAddress = sect->address;
			curLinkEditfileOffset = sect->fileOffset;
		}
		uint16_t maxAlignment = 0;
		uint64_t offset = 0;
		for (std::vector<const ld::Atom*>::iterator ait = sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
			const ld::Atom* atom = *ait;
			//fprintf(stderr, "setting linkedit atom offset for %s\n", atom->name());
			if ( atom->alignment().powerOf2 > maxAlignment )
				maxAlignment = atom->alignment().powerOf2;
			// calculate section offset for this atom
			uint64_t alignment = 1 << atom->alignment().powerOf2;
			uint64_t currentModulus = (offset % alignment);
			uint64_t requiredModulus = atom->alignment().modulus;
			if ( currentModulus != requiredModulus ) {
				if ( requiredModulus > currentModulus )
					offset += requiredModulus-currentModulus;
				else
					offset += requiredModulus+alignment-currentModulus;
			}
			(const_cast<ld::Atom*>(atom))->setSectionOffset(offset);
			(const_cast<ld::Atom*>(atom))->setSectionStartAddress(curLinkEditAddress);
			offset += atom->size();
		}
		sect->size = offset;
		// section alignment is that of a contained atom with the greatest alignment
		sect->alignment = maxAlignment;
		sect->address = curLinkEditAddress;
		sect->fileOffset = curLinkEditfileOffset;
		curLinkEditAddress += sect->size;
		curLinkEditfileOffset += sect->size;
	}
	
	_fileSize = state.sections.back()->fileOffset + state.sections.back()->size;
}


void OutputFile::setLoadCommandsPadding(ld::Internal& state)
{
	// In other sections, any extra space is put and end of segment.
	// In __TEXT segment, any extra space is put after load commands to allow post-processing of load commands
	// Do a reverse layout of __TEXT segment to determine padding size and adjust section size
	uint64_t paddingSize = 0;
	switch ( _options.outputKind() ) {
		case Options::kDyld:
			// dyld itself has special padding requirements.  We want the beginning __text section to start at a stable address
			assert(strcmp(state.sections[1]->sectionName(),"__text") == 0);
			state.sections[1]->alignment = 12; // page align __text
			break;
		case Options::kObjectFile:
			// mach-o .o files need no padding between load commands and first section
			// but leave enough room that the object file could be signed
			paddingSize = 32;
			break;
		case Options::kPreload:
			// mach-o MH_PRELOAD files need no padding between load commands and first section
			paddingSize = 0;
		case Options::kKextBundle:
			if ( _options.useTextExecSegment() ) {
				paddingSize = 32;
				break;
			}
			// else fall into default case
		default:
			// work backwards from end of segment and lay out sections so that extra room goes to padding atom
			uint64_t addr = 0;
			uint64_t textSegPageSize = _options.segPageSize("__TEXT");
			if ( _options.sharedRegionEligible() && _options.platforms().minOS(ld::iOS_8_0) && (textSegPageSize == 0x4000) )
				textSegPageSize = 0x1000;
			for (std::vector<ld::Internal::FinalSection*>::reverse_iterator it = state.sections.rbegin(); it != state.sections.rend(); ++it) {
				ld::Internal::FinalSection* sect = *it;
				if ( strcmp(sect->segmentName(), "__TEXT") != 0 ) 
					continue;
				if ( sect == headerAndLoadCommandsSection ) {
					addr -= headerAndLoadCommandsSection->size;
					paddingSize = addr % textSegPageSize;
					break;
				}
				addr -= sect->size;
				addr = addr & (0 - (1 << sect->alignment));
			}
	
			// if command line requires more padding than this
			uint32_t minPad = _options.minimumHeaderPad();
			if ( _options.maxMminimumHeaderPad() ) {
				// -headerpad_max_install_names means there should be room for every path load command to grow to 1204 bytes
				uint32_t altMin = _dylibsToLoad.size() * MAXPATHLEN;
				if ( _options.outputKind() ==  Options::kDynamicLibrary )
					altMin += MAXPATHLEN;
				if ( altMin > minPad )
					minPad = altMin;
			}
			if ( paddingSize < minPad ) {
				int extraPages = (minPad - paddingSize + _options.segmentAlignment() - 1)/_options.segmentAlignment();
				paddingSize += extraPages * _options.segmentAlignment();
			}
			
			if ( _options.makeEncryptable() ) {
				// load commands must be on a separate non-encrypted page
				int loadCommandsPage = (headerAndLoadCommandsSection->size + minPad)/_options.segmentAlignment();
				int textPage = (headerAndLoadCommandsSection->size + paddingSize)/_options.segmentAlignment();
				if ( loadCommandsPage == textPage ) {
					paddingSize += _options.segmentAlignment();
					textPage += 1;
				}
				// remember start for later use by load command
				_encryptedTEXTstartOffset = textPage*_options.segmentAlignment();
			}
			break;
	}
	// add padding to size of section
	headerAndLoadCommandsSection->size += paddingSize;
}


uint64_t OutputFile::pageAlign(uint64_t addr)
{
	const uint64_t alignment = _options.segmentAlignment();
	return ((addr+alignment-1) & (-alignment)); 
}

uint64_t OutputFile::pageAlign(uint64_t addr, uint64_t pageSize)
{
	return ((addr+pageSize-1) & (-pageSize)); 
}

static const char* makeName(const ld::Atom& atom)
{
	static char buffer[4096];
	switch ( atom.symbolTableInclusion() ) {
		case ld::Atom::symbolTableNotIn:
		case ld::Atom::symbolTableNotInFinalLinkedImages:
			sprintf(buffer, "%s@0x%08llX", atom.name(), atom.objectAddress());
			break;
		case ld::Atom::symbolTableIn:
		case ld::Atom::symbolTableInAndNeverStrip:
		case ld::Atom::symbolTableInAsAbsolute:
		case ld::Atom::symbolTableInWithRandomAutoStripLabel:
			strlcpy(buffer, atom.name(), 4096);
			break;
	}
	return buffer;
}

static const char* referenceTargetAtomName(ld::Internal& state, const ld::Fixup* ref)
{
	switch ( ref->binding ) {
		case ld::Fixup::bindingNone:
			return "NO BINDING";
		case ld::Fixup::bindingByNameUnbound:
			return (char*)(ref->u.target);
		case ld::Fixup::bindingByContentBound:
		case ld::Fixup::bindingDirectlyBound:
			return makeName(*((ld::Atom*)(ref->u.target)));
		case ld::Fixup::bindingsIndirectlyBound:
			return makeName(*state.indirectBindingTable[ref->u.bindingIndex]);
	}
	return "BAD BINDING";
}

bool OutputFile::targetIsThumb(ld::Internal& state, const ld::Fixup* fixup)
{
	switch ( fixup->binding ) {
		case ld::Fixup::bindingByContentBound:
		case ld::Fixup::bindingDirectlyBound:
			return fixup->u.target->isThumb();
		case ld::Fixup::bindingsIndirectlyBound:
			return state.indirectBindingTable[fixup->u.bindingIndex]->isThumb();
		default:
			break;
	}
	throw "unexpected binding";
}

uint64_t OutputFile::addressOf(const ld::Internal& state, const ld::Fixup* fixup, const ld::Atom** target)
{
	// FIXME: Is this right for makeThreadedStartsSection?
	if ( !_options.makeCompressedDyldInfo() && !_options.makeThreadedStartsSection() ) {
		// For external relocations the classic mach-o format
		// has addend only stored in the content.  That means
		// that the address of the target is not used.
		if ( fixup->contentAddendOnly )
			return 0;
	}
	switch ( fixup->binding ) {
		case ld::Fixup::bindingNone:
			throw "unexpected bindingNone";
		case ld::Fixup::bindingByNameUnbound:
			throw "unexpected bindingByNameUnbound";
		case ld::Fixup::bindingByContentBound:
		case ld::Fixup::bindingDirectlyBound:
			*target = fixup->u.target;
			return (*target)->finalAddress();
		case ld::Fixup::bindingsIndirectlyBound:
			*target = state.indirectBindingTable[fixup->u.bindingIndex];
		#ifndef NDEBUG
			if ( ! (*target)->finalAddressMode() ) {
				throwf("reference to symbol (which has not been assigned an address) %s", (*target)->name());
			}
		#endif
			return (*target)->finalAddress();
	}
	throw "unexpected binding";
}

uint64_t OutputFile::addressAndTarget(const ld::Internal& state, const ld::Fixup* fixup, const ld::Atom** target)
{
	switch ( fixup->binding ) {
		case ld::Fixup::bindingNone:
			throw "unexpected bindingNone";
		case ld::Fixup::bindingByNameUnbound:
			throw "unexpected bindingByNameUnbound";
		case ld::Fixup::bindingByContentBound:
		case ld::Fixup::bindingDirectlyBound:
			*target = fixup->u.target;
			return (*target)->finalAddress();
		case ld::Fixup::bindingsIndirectlyBound:
			*target = state.indirectBindingTable[fixup->u.bindingIndex];
		#ifndef NDEBUG
			if ( ! (*target)->finalAddressMode() ) {
				throwf("reference to symbol (which has not been assigned an address) %s", (*target)->name());
			}
		#endif
			return (*target)->finalAddress();
	}
	throw "unexpected binding";
}


uint64_t OutputFile::sectionOffsetOf(const ld::Internal& state, const ld::Fixup* fixup)
{
	const ld::Atom* target = NULL;
	switch ( fixup->binding ) {
		case ld::Fixup::bindingNone:
			throw "unexpected bindingNone";
		case ld::Fixup::bindingByNameUnbound:
			throw "unexpected bindingByNameUnbound";
		case ld::Fixup::bindingByContentBound:
		case ld::Fixup::bindingDirectlyBound:
			target = fixup->u.target;
			break;
		case ld::Fixup::bindingsIndirectlyBound:
			target = state.indirectBindingTable[fixup->u.bindingIndex];
			break;
	}
	assert(target != NULL);
	
	uint64_t targetAddress = target->finalAddress();
	for (std::vector<ld::Internal::FinalSection*>::const_iterator it = state.sections.begin(); it != state.sections.end(); ++it) {
		const ld::Internal::FinalSection* sect = *it;
		if ( (sect->address <= targetAddress) && (targetAddress < (sect->address+sect->size)) )
			return targetAddress - sect->address;
	}
	throw "section not found for section offset";
}



uint64_t OutputFile::tlvTemplateOffsetOf(const ld::Internal& state, const ld::Fixup* fixup)
{
	const ld::Atom* target = NULL;
	switch ( fixup->binding ) {
		case ld::Fixup::bindingNone:
			throw "unexpected bindingNone";
		case ld::Fixup::bindingByNameUnbound:
			throw "unexpected bindingByNameUnbound";
		case ld::Fixup::bindingByContentBound:
		case ld::Fixup::bindingDirectlyBound:
			target = fixup->u.target;
			break;
		case ld::Fixup::bindingsIndirectlyBound:
			target = state.indirectBindingTable[fixup->u.bindingIndex];
			break;
	}
	assert(target != NULL);
	
	for (std::vector<ld::Internal::FinalSection*>::const_iterator it = state.sections.begin(); it != state.sections.end(); ++it) {
		const ld::Internal::FinalSection* sect = *it;
		switch ( sect->type() ) {
			case ld::Section::typeTLVInitialValues:
			case ld::Section::typeTLVZeroFill:
				return target->finalAddress() - sect->address;
			default:
				break;
		}
	}
	throw "section not found for tlvTemplateOffsetOf";
}

void OutputFile::printSectionLayout(ld::Internal& state)
{
	// show layout of final image
	fprintf(stderr, "final section layout:\n");
	for (std::vector<ld::Internal::FinalSection*>::iterator it = state.sections.begin(); it != state.sections.end(); ++it) {
		if ( (*it)->isSectionHidden() )
			continue;
		fprintf(stderr, "    %s/%s addr=0x%08llX, size=0x%08llX, fileOffset=0x%08llX, type=%d\n", 
				(*it)->segmentName(), (*it)->sectionName(), 
				(*it)->address, (*it)->size, (*it)->fileOffset, (*it)->type());
	}
}


void OutputFile::rangeCheck8(int64_t displacement, ld::Internal& state, const ld::Atom* atom, const ld::Fixup* fixup)
{
	if ( (displacement > 127) || (displacement < -128) ) {
		// show layout of final image
		printSectionLayout(state);
		
		const ld::Atom* target;	
		throwf("8-bit reference out of range (%lld max is +/-127B): from %s (0x%08llX) to %s (0x%08llX)", 
				displacement, atom->name(), atom->finalAddress(), referenceTargetAtomName(state, fixup), 
				addressOf(state, fixup, &target));
	}
}

void OutputFile::rangeCheck16(int64_t displacement, ld::Internal& state, const ld::Atom* atom, const ld::Fixup* fixup)
{
	const int64_t thirtyTwoKLimit  = 0x00007FFF;
	if ( (displacement > thirtyTwoKLimit) || (displacement < (-thirtyTwoKLimit)) ) {
		// show layout of final image
		printSectionLayout(state);
		
		const ld::Atom* target;	
		throwf("16-bit reference out of range (%lld max is +/-32KB): from %s (0x%08llX) to %s (0x%08llX)", 
				displacement, atom->name(), atom->finalAddress(), referenceTargetAtomName(state, fixup),  
				addressOf(state, fixup, &target));
	}
}

void OutputFile::rangeCheckBranch32(int64_t displacement, ld::Internal& state, const ld::Atom* atom, const ld::Fixup* fixup)
{
	const int64_t twoGigLimit  = 0x7FFFFFFF;
	if ( (displacement > twoGigLimit) || (displacement < (-twoGigLimit)) ) {
		// show layout of final image
		printSectionLayout(state);
		
		const ld::Atom* target;	
		throwf("32-bit branch out of range (%lld max is +/-2GB): from %s (0x%08llX) to %s (0x%08llX)",
				displacement, atom->name(), atom->finalAddress(), referenceTargetAtomName(state, fixup), 
				addressOf(state, fixup, &target));
	}
}


void OutputFile::rangeCheckAbsolute32(int64_t displacement, ld::Internal& state, const ld::Atom* atom, const ld::Fixup* fixup)
{
	const int64_t fourGigLimit  = 0xFFFFFFFF;
	if ( displacement > fourGigLimit ) {
		// <rdar://problem/9610466> cannot enforce 32-bit range checks on 32-bit archs because assembler loses sign information
		//  .long _foo - 0xC0000000
		// is encoded in mach-o the same as:
		//  .long _foo + 0x40000000
		// so if _foo lays out to 0xC0000100, the first is ok, but the second is not.  
		if ( (_options.architecture() == CPU_TYPE_ARM) || (_options.architecture() == CPU_TYPE_I386) ) {
			// Unlikely userland code does funky stuff like this, so warn for them, but not warn for -preload or -static
			if ( (_options.outputKind() != Options::kPreload) && (_options.outputKind() != Options::kStaticExecutable) ) {
				warning("32-bit absolute address out of range (0x%08llX max is 4GB): from %s + 0x%08X (0x%08llX) to 0x%08llX", 
						displacement, atom->name(), fixup->offsetInAtom, atom->finalAddress(), displacement);
			}
			return;
		}
		// show layout of final image
		printSectionLayout(state);
		
		const ld::Atom* target;	
		if ( fixup->binding == ld::Fixup::bindingNone )
			throwf("32-bit absolute address out of range (0x%08llX max is 4GB): from %s + 0x%08X (0x%08llX) to 0x%08llX", 
				displacement, atom->name(), fixup->offsetInAtom, atom->finalAddress(), displacement);
		else
			throwf("32-bit absolute address out of range (0x%08llX max is 4GB): from %s + 0x%08X (0x%08llX) to %s (0x%08llX)", 
				displacement, atom->name(), fixup->offsetInAtom, atom->finalAddress(), referenceTargetAtomName(state, fixup), 
				addressOf(state, fixup, &target));
	}
}


void OutputFile::rangeCheckRIP32(int64_t displacement, ld::Internal& state, const ld::Atom* atom, const ld::Fixup* fixup)
{
	const int64_t twoGigLimit  = 0x7FFFFFFF;
	if ( (displacement > twoGigLimit) || (displacement < (-twoGigLimit)) ) {	
		// show layout of final image
		printSectionLayout(state);
		
		const ld::Atom* target;	
		throwf("32-bit RIP relative reference out of range (%lld max is +/-2GB): from %s (0x%08llX) to %s (0x%08llX)",
				displacement, atom->name(), atom->finalAddress(), referenceTargetAtomName(state, fixup), 
				addressOf(state, fixup, &target));
	}
}

void OutputFile::rangeCheckARM12(int64_t displacement, ld::Internal& state, const ld::Atom* atom, const ld::Fixup* fixup)
{
	if ( (displacement > 4092LL) || (displacement < (-4092LL)) ) {
		// show layout of final image
		printSectionLayout(state);
		
		const ld::Atom* target;	
		throwf("ARM ldr 12-bit displacement out of range (%lld max is +/-4096B): from %s (0x%08llX) to %s (0x%08llX)", 
				displacement, atom->name(), atom->finalAddress(), referenceTargetAtomName(state, fixup), 
				addressOf(state, fixup, &target));
	}
}

bool OutputFile::checkArmBranch24Displacement(int64_t displacement)
{
	return ( (displacement < 33554428LL) && (displacement > (-33554432LL)) );
}

void OutputFile::rangeCheckARMBranch24(int64_t displacement, ld::Internal& state, const ld::Atom* atom, const ld::Fixup* fixup)
{
	if ( checkArmBranch24Displacement(displacement) )
		return;
		
	// show layout of final image
	printSectionLayout(state);
	
	const ld::Atom* target;	
	throwf("b/bl/blx ARM branch out of range (%lld max is +/-32MB): from %s (0x%08llX) to %s (0x%08llX)", 
			displacement, atom->name(), atom->finalAddress(), referenceTargetAtomName(state, fixup), 
			addressOf(state, fixup, &target));
}

bool OutputFile::checkThumbBranch22Displacement(int64_t displacement)
{
	// thumb2 supports  +/- 16MB displacement
	if ( _options.preferSubArchitecture() && _options.archSupportsThumb2() ) {
		if ( (displacement > 16777214LL) || (displacement < (-16777216LL)) ) {
			return false;
		}
	}
	else {
		// thumb1 supports +/- 4MB displacement
		if ( (displacement > 4194302LL) || (displacement < (-4194304LL)) ) {
			return false;
		}
	}
	return true;
}

void OutputFile::rangeCheckThumbBranch22(int64_t displacement, ld::Internal& state, const ld::Atom* atom, const ld::Fixup* fixup)
{
	if ( checkThumbBranch22Displacement(displacement) )
		return;

	// show layout of final image
	printSectionLayout(state);

	const ld::Atom* target;	
	if ( _options.preferSubArchitecture() && _options.archSupportsThumb2() ) {
		throwf("b/bl/blx thumb2 branch out of range (%lld max is +/-16MB): from %s (0x%08llX) to %s (0x%08llX)", 
				displacement, atom->name(), atom->finalAddress(), referenceTargetAtomName(state, fixup), 
				addressOf(state, fixup, &target));
	}
	else {
		throwf("b/bl/blx thumb1 branch out of range (%lld max is +/-4MB): from %s (0x%08llX) to %s (0x%08llX)", 
				displacement, atom->name(), atom->finalAddress(), referenceTargetAtomName(state, fixup), 
				addressOf(state, fixup, &target));
	}
}


void OutputFile::rangeCheckARM64Branch26(int64_t displacement, ld::Internal& state, const ld::Atom* atom, const ld::Fixup* fixup)
{
	const int64_t bl_128MegLimit = 0x07FFFFFF;
	if ( (displacement > bl_128MegLimit) || (displacement < (-bl_128MegLimit)) ) {
		// show layout of final image
		printSectionLayout(state);
		
		const ld::Atom* target;	
		throwf("b(l) ARM64 branch out of range (%lld max is +/-128MB): from %s (0x%08llX) to %s (0x%08llX)", 
				displacement, atom->name(), atom->finalAddress(), referenceTargetAtomName(state, fixup), 
				addressOf(state, fixup, &target));
	}
}

void OutputFile::rangeCheckARM64Page21(int64_t displacement, ld::Internal& state, const ld::Atom* atom, const ld::Fixup* fixup)
{
	const int64_t adrp_4GigLimit = 0x100000000ULL;
	if ( (displacement > adrp_4GigLimit) || (displacement < (-adrp_4GigLimit)) ) {
		// show layout of final image
		printSectionLayout(state);
		
		const ld::Atom* target;	
		throwf("ARM64 ADRP out of range (%lld max is +/-4GB): from %s (0x%08llX) to %s (0x%08llX)", 
				displacement, atom->name(), atom->finalAddress(), referenceTargetAtomName(state, fixup), 
				addressOf(state, fixup, &target));
	}
}


uint16_t OutputFile::get16LE(uint8_t* loc) { return LittleEndian::get16(*(uint16_t*)loc); }
void     OutputFile::set16LE(uint8_t* loc, uint16_t value) { LittleEndian::set16(*(uint16_t*)loc, value); }

uint32_t OutputFile::get32LE(uint8_t* loc) { return LittleEndian::get32(*(uint32_t*)loc); }
void     OutputFile::set32LE(uint8_t* loc, uint32_t value) { LittleEndian::set32(*(uint32_t*)loc, value); }

uint64_t OutputFile::get64LE(uint8_t* loc) { return LittleEndian::get64(*(uint64_t*)loc); }
void     OutputFile::set64LE(uint8_t* loc, uint64_t value) { LittleEndian::set64(*(uint64_t*)loc, value); }

uint16_t OutputFile::get16BE(uint8_t* loc) { return BigEndian::get16(*(uint16_t*)loc); }
void     OutputFile::set16BE(uint8_t* loc, uint16_t value) { BigEndian::set16(*(uint16_t*)loc, value); }

uint32_t OutputFile::get32BE(uint8_t* loc) { return BigEndian::get32(*(uint32_t*)loc); }
void     OutputFile::set32BE(uint8_t* loc, uint32_t value) { BigEndian::set32(*(uint32_t*)loc, value); }

uint64_t OutputFile::get64BE(uint8_t* loc) { return BigEndian::get64(*(uint64_t*)loc); }
void     OutputFile::set64BE(uint8_t* loc, uint64_t value) { BigEndian::set64(*(uint64_t*)loc, value); }

#if SUPPORT_ARCH_arm64

static uint32_t makeNOP() {
	return 0xD503201F;
}

enum SignExtension { signedNot, signed32, signed64 };
struct LoadStoreInfo {
	uint32_t		reg;
	uint32_t		baseReg;
	uint32_t		offset;		// after scaling
	uint32_t		size;		// 1,2,4,8, or 16
	bool			isStore;
	bool			isFloat;	// if destReg is FP/SIMD
	SignExtension	signEx;		// if load is sign extended
};

static uint32_t makeLDR_literal(const LoadStoreInfo& info, uint64_t targetAddress, uint64_t instructionAddress) 
{
	int64_t delta = targetAddress - instructionAddress;
	assert(delta < 1024*1024);
	assert(delta > -1024*1024);
	assert((info.reg & 0xFFFFFFE0) == 0);
	assert((targetAddress & 0x3) == 0);
	assert((instructionAddress & 0x3) == 0);
	assert(!info.isStore);
	uint32_t imm19 = (delta << 3) & 0x00FFFFE0;
	uint32_t instruction = 0;
	switch ( info.size ) {
		case 4:
			if ( info.isFloat ) {
				assert(info.signEx == signedNot);
				instruction = 0x1C000000;
			}
			else {
				if ( info.signEx == signed64 )
					instruction = 0x98000000;
				else
					instruction = 0x18000000;
			}
			break;
		case 8:
			assert(info.signEx == signedNot);
			instruction = info.isFloat ? 0x5C000000 : 0x58000000;
			break;
		case 16:
			assert(info.signEx == signedNot);
			instruction = 0x9C000000;
			break;
		default:
			assert(0 && "invalid load size for literal");
	}
	return (instruction | imm19 | info.reg);
}

static uint32_t makeADR(uint32_t destReg, uint64_t targetAddress, uint64_t instructionAddress)
{
	assert((destReg & 0xFFFFFFE0) == 0);
	assert((instructionAddress & 0x3) == 0);
	uint32_t instruction = 0x10000000;
	int64_t delta = targetAddress - instructionAddress;
	assert(delta < 1024*1024);
	assert(delta > -1024*1024);
	uint32_t immhi = (delta & 0x001FFFFC) << 3;
	uint32_t immlo = (delta & 0x00000003) << 29;
	return (instruction | immhi | immlo | destReg); 
}

static uint32_t makeLoadOrStore(const LoadStoreInfo& info)
{
	uint32_t instruction = 0x39000000;
	if ( info.isFloat )
		instruction |= 0x04000000;
	instruction |= info.reg;
	instruction |= (info.baseReg << 5);
	uint32_t sizeBits = 0;
	uint32_t opcBits = 0;
	uint32_t imm12Bits = 0;
	switch ( info.size ) {
		case 1:
			sizeBits = 0;
			imm12Bits = info.offset;
			if ( info.isStore ) {
				opcBits = 0;
			}
			else {
				switch ( info.signEx ) {
					case signedNot:
						opcBits = 1;
						break;
					case signed32:
						opcBits = 3;
						break;
					case signed64:
						opcBits = 2;
						break;
				}
			}
			break;
		case 2:
			sizeBits = 1;
			assert((info.offset % 2) == 0);
			imm12Bits = info.offset/2;
			if ( info.isStore ) {
				opcBits = 0;
			}
			else {
				switch ( info.signEx ) {
					case signedNot:
						opcBits = 1;
						break;
					case signed32:
						opcBits = 3;
						break;
					case signed64:
						opcBits = 2;
						break;
				}
			}
			break;
		case 4:
			sizeBits = 2;
			assert((info.offset % 4) == 0);
			imm12Bits = info.offset/4;
			if ( info.isStore ) {
				opcBits = 0;
			}
			else {
				switch ( info.signEx ) {
					case signedNot:
						opcBits = 1;
						break;
					case signed32:
						assert(0 && "cannot use signed32 with 32-bit load/store");
						break;
					case signed64:
						opcBits = 2;
						break;
				}
			}
			break;
		case 8:
			sizeBits = 3;
			assert((info.offset % 8) == 0);
			imm12Bits = info.offset/8;
			if ( info.isStore ) {
				opcBits = 0;
			}
			else {
				opcBits = 1;
				assert(info.signEx == signedNot);
			}
			break;
		case 16:
			sizeBits = 0;
			assert((info.offset % 16) == 0);
			imm12Bits = info.offset/16;
			assert(info.isFloat);
			if ( info.isStore ) {
				opcBits = 2;
			}
			else {
				opcBits = 3;
			}
			break;
		default:
			assert(0 && "bad load/store size");
			break;
	}
	assert(imm12Bits < 4096);
	return (instruction | (sizeBits << 30) | (opcBits << 22) | (imm12Bits << 10));
}

static bool parseLoadOrStore(uint32_t instruction, LoadStoreInfo& info) 
{
	if ( (instruction & 0x3B000000) != 0x39000000 ) 
		return false;
	info.isFloat = ( (instruction & 0x04000000) != 0 );
	info.reg = (instruction & 0x1F);
	info.baseReg = ((instruction>>5) & 0x1F);
	switch (instruction & 0xC0C00000) {
		case 0x00000000:
			info.size = 1;
			info.isStore = true;
			info.signEx = signedNot;
			break;
		case 0x00400000:
			info.size = 1;
			info.isStore = false;
			info.signEx = signedNot;
			break;
		case 0x00800000:
			if ( info.isFloat ) {
				info.size = 16;
				info.isStore = true;
				info.signEx = signedNot;
			}
			else {
				info.size = 1;
				info.isStore = false;
				info.signEx = signed64;
			}
			break;
		case 0x00C00000:
			if ( info.isFloat ) {
				info.size = 16;
				info.isStore = false;
				info.signEx = signedNot;
			}
			else {
				info.size = 1;
				info.isStore = false;
				info.signEx = signed32;
			}
			break;
		case 0x40000000:
			info.size = 2;
			info.isStore = true;
			info.signEx = signedNot;
			break;
		case 0x40400000:
			info.size = 2;
			info.isStore = false;
			info.signEx = signedNot;
			break;
		case 0x40800000:
			info.size = 2;
			info.isStore = false;
			info.signEx = signed64;
			break;
		case 0x40C00000:
			info.size = 2;
			info.isStore = false;
			info.signEx = signed32;
			break;
		case 0x80000000:
			info.size = 4;
			info.isStore = true;
			info.signEx = signedNot;
			break;
		case 0x80400000:
			info.size = 4;
			info.isStore = false;
			info.signEx = signedNot;
			break;
		case 0x80800000:
			info.size = 4;
			info.isStore = false;
			info.signEx = signed64;
			break;
		case 0xC0000000:
			info.size = 8;
			info.isStore = true;
			info.signEx = signedNot;
			break;
		case 0xC0400000:
			info.size = 8;
			info.isStore = false;
			info.signEx = signedNot;
			break;
		default:
			return false;
	}
	info.offset = ((instruction >> 10) & 0x0FFF) * info.size;
	return true;	
}

struct AdrpInfo {
	uint32_t	destReg;
};

static bool parseADRP(uint32_t instruction, AdrpInfo& info) 
{
	if ( (instruction & 0x9F000000) != 0x90000000 )
		return false;
	info.destReg = (instruction & 0x1F);
	return true;
}

struct AddInfo {
	uint32_t	destReg;
	uint32_t	srcReg;
	uint32_t	addend;
};

static bool parseADD(uint32_t instruction, AddInfo& info) 
{
	if ( (instruction & 0xFFC00000) != 0x91000000 )
		return false;
	info.destReg = (instruction & 0x1F);
	info.srcReg = ((instruction>>5) & 0x1F);
	info.addend = ((instruction>>10) & 0xFFF);
	return true;
}



#if 0
static uint32_t makeLDR_scaledOffset(const LoadStoreInfo& info) 
{
	assert((info.reg & 0xFFFFFFE0) == 0);
	assert((info.baseReg & 0xFFFFFFE0) == 0);
	assert(!info.isFloat || (info.signEx != signedNot));
	uint32_t sizeBits = 0;
	uint32_t opcBits = 1;
	uint32_t vBit = info.isFloat;
	switch ( info.signEx ) {
		case signedNot:
			opcBits = 1;
			break;
		case signed32:
			opcBits = 3;
			break;
		case signed64:
			opcBits = 2;
			break;
		default:
			assert(0 && "bad SignExtension runtime value");
	}
	switch ( info.size ) {
		case 1:
			sizeBits = 0;
			break;
		case 2:
			sizeBits = 1;
			break;
		case 4:
			sizeBits = 2;
			break;
		case 8:
			sizeBits = 3;
			break;
		case 16:
			sizeBits = 0;
			vBit = 1;
			opcBits = 3;
			break;
		default:
			assert(0 && "invalid load size for literal");
	}
	assert((info.offset % info.size) == 0);
	uint32_t scaledOffset = info.offset/info.size;
	assert(scaledOffset < 4096);
	return (0x39000000 | (sizeBits<<30) | (vBit<<26) | (opcBits<<22) | (scaledOffset<<10) | (info.baseReg<<5) | info.reg);
}

static uint32_t makeLDR_literal(uint32_t destReg, uint32_t loadSize, bool isFloat, uint64_t targetAddress, uint64_t instructionAddress) 
{
	int64_t delta = targetAddress - instructionAddress;
	assert(delta < 1024*1024);
	assert(delta > -1024*1024);
	assert((destReg & 0xFFFFFFE0) == 0);
	assert((targetAddress & 0x3) == 0);
	assert((instructionAddress & 0x3) == 0);
	uint32_t imm19 = (delta << 3) & 0x00FFFFE0;
	uint32_t instruction = 0;
	switch ( loadSize ) {
		case 4:
			instruction = isFloat ? 0x1C000000 : 0x18000000;
			break;
		case 8:
			instruction = isFloat ? 0x5C000000 : 0x58000000;
			break;
		case 16:
			instruction = 0x9C000000;
			break;
		default:
			assert(0 && "invalid load size for literal");
	}
	return (instruction | imm19 | destReg);
}


static bool ldrInfo(uint32_t instruction, uint8_t* size, uint8_t* destReg, bool* v, uint32_t* scaledOffset)
{
	*v = ( (instruction & 0x04000000) != 0 );
	*destReg = (instruction & 0x1F);
	uint32_t imm12 = ((instruction >> 10) & 0x00000FFF);
	switch ( (instruction & 0xC0000000) >> 30 ) {
		case 0:
			// vector and byte LDR have same "size" bits, need to check other bits to differenciate
			if ( (instruction & 0x00800000) == 0 ) {
				*size = 1;
				*scaledOffset = imm12;
			}
			else {
				*size = 16;
				*scaledOffset = imm12 * 16;
			}
			break;
		case 1:
			*size = 2;
			*scaledOffset = imm12 * 2;
			break;
		case 2:
			*size = 4;
			*scaledOffset = imm12 * 4;
			break;
		case 3:
			*size = 8;
			*scaledOffset = imm12 * 8;
			break;
	}
	return ((instruction & 0x3B400000) == 0x39400000);
}
#endif

static bool withinOneMeg(uint64_t addr1, uint64_t addr2) {
	int64_t delta = (addr2 - addr1);
	return ( (delta < 1024*1024) && (delta > -1024*1024) );
}
#endif // SUPPORT_ARCH_arm64

void OutputFile::setInfo(ld::Internal& state, const ld::Atom* atom, uint8_t* buffer, const std::map<uint32_t, const Fixup*>& usedByHints, 
						uint32_t offsetInAtom, uint32_t delta, InstructionInfo* info) 
{
	info->offsetInAtom = offsetInAtom + delta;
	std::map<uint32_t, const Fixup*>::const_iterator pos = usedByHints.find(info->offsetInAtom);
	if ( (pos != usedByHints.end()) && (pos->second != NULL) ) {
		info->fixup = pos->second;
		info->targetAddress = addressOf(state, info->fixup, &info->target);
		if ( info->fixup->clusterSize != ld::Fixup::k1of1 ) {
			assert(info->fixup->firstInCluster());
			const ld::Fixup* nextFixup = info->fixup + 1;
			if ( nextFixup->kind == ld::Fixup::kindAddAddend ) {
				info->targetAddress += nextFixup->u.addend;
			}
			else {
				assert(0 && "expected addend");
			}
		}
	}
	else {
		info->fixup = NULL;
		info->targetAddress = 0;
		info->target = NULL;
	}
	info->instructionContent = &buffer[info->offsetInAtom];
	info->instructionAddress = atom->finalAddress() + info->offsetInAtom;
	info->instruction = get32LE(info->instructionContent);
}	

#if SUPPORT_ARCH_arm64
static bool isPageKind(const ld::Fixup* fixup, bool mustBeGOT=false)
{
	if ( fixup == NULL )
		return false;
	const ld::Fixup* f;
	switch ( fixup->kind ) {
		case ld::Fixup::kindStoreTargetAddressARM64Page21:
			return !mustBeGOT;
		case ld::Fixup::kindStoreTargetAddressARM64GOTLoadPage21:
		case ld::Fixup::kindStoreTargetAddressARM64GOTLeaPage21:
		case ld::Fixup::kindStoreTargetAddressARM64TLVPLoadPage21:
		case ld::Fixup::kindStoreTargetAddressARM64TLVPLoadNowLeaPage21:
			return true;
		case ld::Fixup::kindSetTargetAddress:
			f = fixup;
			do { 
				++f;
			} while ( ! f->lastInCluster() );
			switch (f->kind ) {
				case ld::Fixup::kindStoreARM64Page21:
					return !mustBeGOT;
				case ld::Fixup::kindStoreARM64GOTLoadPage21:
				case ld::Fixup::kindStoreARM64GOTLeaPage21:
				case ld::Fixup::kindStoreARM64TLVPLoadPage21:
				case ld::Fixup::kindStoreARM64TLVPLoadNowLeaPage21:
					return true;
				default:
					break;
			}
			break;
		default:
			break;
	}
	return false;
}

static bool isPageOffsetKind(const ld::Fixup* fixup, bool mustBeGOT=false)
{
	if ( fixup == NULL )
		return false;
	const ld::Fixup* f;
	switch ( fixup->kind ) {
		case ld::Fixup::kindStoreTargetAddressARM64PageOff12:
			return !mustBeGOT;
		case ld::Fixup::kindStoreTargetAddressARM64GOTLoadPageOff12:
		case ld::Fixup::kindStoreTargetAddressARM64GOTLeaPageOff12:
		case ld::Fixup::kindStoreTargetAddressARM64TLVPLoadPageOff12:
		case ld::Fixup::kindStoreTargetAddressARM64TLVPLoadNowLeaPageOff12:
			return true;
		case ld::Fixup::kindSetTargetAddress:
			f = fixup;
			do { 
				++f;
			} while ( ! f->lastInCluster() );
			switch (f->kind ) {
				case ld::Fixup::kindStoreARM64PageOff12:
					return !mustBeGOT;
				case ld::Fixup::kindStoreARM64GOTLoadPageOff12:
				case ld::Fixup::kindStoreARM64GOTLeaPageOff12:
				case ld::Fixup::kindStoreARM64TLVPLoadPageOff12:
				case ld::Fixup::kindStoreARM64TLVPLoadNowLeaPageOff12:
					return true;
				default:
					break;
			}
			break;
		default:
			break;
	}
	return false;
}
#endif // SUPPORT_ARCH_arm64


#define LOH_ASSERT(cond) \
	if ( !(cond) ) { \
		warning("ignoring linker optimization hint at %s+0x%X because " #cond, atom->name(), fit->offsetInAtom); \
		break; \
	} 

void OutputFile::applyFixUps(ld::Internal& state, uint64_t mhAddress, const ld::Atom* atom, uint8_t* buffer)
{
	//fprintf(stderr, "applyFixUps() on %s\n", atom->name());
	int64_t accumulator = 0;
	const ld::Atom* toTarget = NULL;	
	const ld::Atom* fromTarget;
	int64_t delta;
	uint32_t instruction;
	uint32_t newInstruction;
	bool is_bl;
	bool is_blx;
	bool is_b;
	bool thumbTarget = false;
	std::map<uint32_t, const Fixup*> usedByHints;
#if SUPPORT_ARCH_arm64e
	Fixup::AuthData authData;
#endif
	for (ld::Fixup::iterator fit = atom->fixupsBegin(), end=atom->fixupsEnd(); fit != end; ++fit) {
		uint8_t* fixUpLocation = &buffer[fit->offsetInAtom];
		ld::Fixup::LOH_arm64 lohExtra;
		switch ( (ld::Fixup::Kind)(fit->kind) ) { 
			case ld::Fixup::kindNone:
			case ld::Fixup::kindNoneFollowOn:
			case ld::Fixup::kindNoneGroupSubordinate:
			case ld::Fixup::kindNoneGroupSubordinateFDE:
			case ld::Fixup::kindNoneGroupSubordinateLSDA:
			case ld::Fixup::kindNoneGroupSubordinatePersonality:
				break;
			case ld::Fixup::kindSetTargetAddress:
				accumulator = addressOf(state, fit, &toTarget);			
				thumbTarget = targetIsThumb(state, fit);
				if ( thumbTarget ) 
					accumulator |= 1;
				if ( fit->contentAddendOnly || fit->contentDetlaToAddendOnly )
					accumulator = 0;
				break;
			case ld::Fixup::kindSubtractTargetAddress:
				delta = addressOf(state, fit, &fromTarget);
				if ( ! fit->contentAddendOnly )
					accumulator -= delta;
				break;
			case ld::Fixup::kindAddAddend:
				if ( ! fit->contentIgnoresAddend ) {
					// <rdar://problem/8342028> ARM main executables main contain .long constants pointing
					// into themselves such as jump tables.  These .long should not have thumb bit set
					// even though the target is a thumb instruction. We can tell it is an interior pointer
					// because we are processing an addend. 
					if ( thumbTarget && (toTarget == atom) && ((int32_t)fit->u.addend > 0) ) {
						accumulator &= (-2);
						//warning("removing thumb bit from intra-atom pointer in %s %s+0x%0X", 
						//		atom->section().sectionName(), atom->name(), fit->offsetInAtom);
					}
					accumulator += fit->u.addend;
				}
				break;
			case ld::Fixup::kindSubtractAddend:
				accumulator -= fit->u.addend;
				break;
			case ld::Fixup::kindSetTargetImageOffset:
				accumulator = addressOf(state, fit, &toTarget) - mhAddress;
				thumbTarget = targetIsThumb(state, fit);
				if ( thumbTarget ) 
					accumulator |= 1;
				break;
			case ld::Fixup::kindSetTargetSectionOffset:
				accumulator = sectionOffsetOf(state, fit);
				break;
			case ld::Fixup::kindSetTargetTLVTemplateOffset:
				accumulator = tlvTemplateOffsetOf(state, fit);
				break;
			case ld::Fixup::kindStore8:
				*fixUpLocation += accumulator;
				break;
			case ld::Fixup::kindStoreLittleEndian16:
				set16LE(fixUpLocation, accumulator);
				break;
			case ld::Fixup::kindStoreLittleEndianLow24of32:
				set32LE(fixUpLocation, (get32LE(fixUpLocation) & 0xFF000000) | (accumulator & 0x00FFFFFF) );
				break;
			case ld::Fixup::kindStoreLittleEndian32:
				rangeCheckAbsolute32(accumulator, state, atom, fit);
				set32LE(fixUpLocation, accumulator);
				break;
			case ld::Fixup::kindStoreLittleEndian64:
				set64LE(fixUpLocation, accumulator);
				break;
			case ld::Fixup::kindStoreBigEndian16:
				set16BE(fixUpLocation, accumulator);
				break;
			case ld::Fixup::kindStoreBigEndianLow24of32:
				set32BE(fixUpLocation, (get32BE(fixUpLocation) & 0xFF000000) | (accumulator & 0x00FFFFFF) );
				break;
			case ld::Fixup::kindStoreBigEndian32:
				rangeCheckAbsolute32(accumulator, state, atom, fit);
				set32BE(fixUpLocation, accumulator);
				break;
			case ld::Fixup::kindStoreBigEndian64:
				set64BE(fixUpLocation, accumulator);
				break;
			case ld::Fixup::kindStoreX86PCRel8:
			case ld::Fixup::kindStoreX86BranchPCRel8:
				if ( fit->contentAddendOnly )
					delta = accumulator;
				else
					delta = accumulator - (atom->finalAddress() + fit->offsetInAtom + 1);
				rangeCheck8(delta, state, atom, fit);
				*fixUpLocation = delta;
				break;
			case ld::Fixup::kindStoreX86PCRel16:
				if ( fit->contentAddendOnly )
					delta = accumulator;
				else
					delta = accumulator - (atom->finalAddress() + fit->offsetInAtom + 2);
				rangeCheck16(delta, state, atom, fit);
				set16LE(fixUpLocation, delta);
				break;
			case ld::Fixup::kindStoreX86BranchPCRel32:
				if ( fit->contentAddendOnly )
					delta = accumulator;
				else
					delta = accumulator - (atom->finalAddress() + fit->offsetInAtom + 4);
				rangeCheckBranch32(delta, state, atom, fit);
				set32LE(fixUpLocation, delta);
				break;
			case ld::Fixup::kindStoreX86PCRel32GOTLoad:
			case ld::Fixup::kindStoreX86PCRel32GOT:
			case ld::Fixup::kindStoreX86PCRel32:
			case ld::Fixup::kindStoreX86PCRel32TLVLoad:
				if ( fit->contentAddendOnly )
					delta = accumulator;
				else
					delta = accumulator - (atom->finalAddress() + fit->offsetInAtom + 4);
				rangeCheckRIP32(delta, state, atom, fit);
				set32LE(fixUpLocation, delta);
				break;
			case ld::Fixup::kindStoreX86PCRel32_1:
				if ( fit->contentAddendOnly )
					delta = accumulator - 1;
				else
					delta = accumulator - (atom->finalAddress() + fit->offsetInAtom + 5);
				rangeCheckRIP32(delta, state, atom, fit);
				set32LE(fixUpLocation, delta);
				break;
			case ld::Fixup::kindStoreX86PCRel32_2:
				if ( fit->contentAddendOnly )
					delta = accumulator - 2;
				else
					delta = accumulator - (atom->finalAddress() + fit->offsetInAtom + 6);
				rangeCheckRIP32(delta, state, atom, fit);
				set32LE(fixUpLocation, delta);
				break;
			case ld::Fixup::kindStoreX86PCRel32_4:
				if ( fit->contentAddendOnly )
					delta = accumulator - 4;
				else
					delta = accumulator - (atom->finalAddress() + fit->offsetInAtom + 8);
				rangeCheckRIP32(delta, state, atom, fit);
				set32LE(fixUpLocation, delta);
				break;
			case ld::Fixup::kindStoreX86Abs32TLVLoad:
				set32LE(fixUpLocation, accumulator);
				break;
			case ld::Fixup::kindStoreX86Abs32TLVLoadNowLEA:
				assert(_options.outputKind() != Options::kObjectFile);
				// TLV entry was optimized away, change movl instruction to a leal
				if ( fixUpLocation[-1] != 0xA1 )
					throw "TLV load reloc does not point to a movl instruction";
				fixUpLocation[-1] = 0xB8;
				set32LE(fixUpLocation, accumulator);
				break;
			case ld::Fixup::kindStoreX86PCRel32GOTLoadNowLEA:
				assert(_options.outputKind() != Options::kObjectFile);
				// GOT entry was optimized away, change movq instruction to a leaq
				if ( fixUpLocation[-2] != 0x8B )
					throw "GOT load reloc does not point to a movq instruction";
				fixUpLocation[-2] = 0x8D;
				delta = accumulator - (atom->finalAddress() + fit->offsetInAtom + 4);
				rangeCheckRIP32(delta, state, atom, fit);
				set32LE(fixUpLocation, delta);
				break;
			case ld::Fixup::kindStoreX86PCRel32TLVLoadNowLEA:
				assert(_options.outputKind() != Options::kObjectFile);
				// TLV entry was optimized away, change movq instruction to a leaq
				if ( fixUpLocation[-2] != 0x8B )
					throw "TLV load reloc does not point to a movq instruction";
				fixUpLocation[-2] = 0x8D;
				delta = accumulator - (atom->finalAddress() + fit->offsetInAtom + 4);
				rangeCheckRIP32(delta, state, atom, fit);
				set32LE(fixUpLocation, delta);
				break;
			case ld::Fixup::kindStoreTargetAddressARMLoad12:
				accumulator = addressOf(state, fit, &toTarget);
				// fall into kindStoreARMLoad12 case
			case ld::Fixup::kindStoreARMLoad12:
				delta = accumulator - (atom->finalAddress() + fit->offsetInAtom + 8);
				rangeCheckARM12(delta, state, atom, fit);
				instruction = get32LE(fixUpLocation);
				if ( delta >= 0 ) {
					newInstruction = instruction & 0xFFFFF000;
					newInstruction |= ((uint32_t)delta & 0xFFF);
				}
				else {
					newInstruction = instruction & 0xFF7FF000;
					newInstruction |= ((uint32_t)(-delta) & 0xFFF);
				}
				set32LE(fixUpLocation, newInstruction);
				break;
			case ld::Fixup::kindDtraceExtra:
				break;
			case ld::Fixup::kindStoreX86DtraceCallSiteNop:
				if ( _options.outputKind() != Options::kObjectFile ) {
					// change call site to a NOP
					fixUpLocation[-1] = 0x90;	// 1-byte nop
					fixUpLocation[0] = 0x0F;	// 4-byte nop 
					fixUpLocation[1] = 0x1F;
					fixUpLocation[2] = 0x40;
					fixUpLocation[3] = 0x00;
				}
				break;
			case ld::Fixup::kindStoreX86DtraceIsEnableSiteClear:
				if ( _options.outputKind() != Options::kObjectFile ) {
					// change call site to a clear eax
					fixUpLocation[-1] = 0x33;		// xorl eax,eax
					fixUpLocation[0] = 0xC0;
					fixUpLocation[1] = 0x90;		// 1-byte nop
					fixUpLocation[2] = 0x90;		// 1-byte nop
					fixUpLocation[3] = 0x90;		// 1-byte nop
				}
				break;
			case ld::Fixup::kindStoreARMDtraceCallSiteNop:
				if ( _options.outputKind() != Options::kObjectFile ) {
					// change call site to a NOP
					set32LE(fixUpLocation, 0xE1A00000);
				}
				break;
			case ld::Fixup::kindStoreARMDtraceIsEnableSiteClear:
				if ( _options.outputKind() != Options::kObjectFile ) {
					// change call site to 'eor r0, r0, r0'
					set32LE(fixUpLocation, 0xE0200000);
				}
				break;
			case ld::Fixup::kindStoreThumbDtraceCallSiteNop:
				if ( _options.outputKind() != Options::kObjectFile ) {
					// change 32-bit blx call site to two thumb NOPs
					set32LE(fixUpLocation, 0x46C046C0);
				}
				break;
			case ld::Fixup::kindStoreThumbDtraceIsEnableSiteClear:
				if ( _options.outputKind() != Options::kObjectFile ) {
					// change 32-bit blx call site to 'nop', 'eor r0, r0'
					set32LE(fixUpLocation, 0x46C04040);
				}
				break;
			case ld::Fixup::kindStoreARM64DtraceCallSiteNop:
				if ( _options.outputKind() != Options::kObjectFile ) {
					// change call site to a NOP
					set32LE(fixUpLocation, 0xD503201F);
				}
				break;
			case ld::Fixup::kindStoreARM64DtraceIsEnableSiteClear:
				if ( _options.outputKind() != Options::kObjectFile ) {
					// change call site to 'MOVZ X0,0'
					set32LE(fixUpLocation, 0xD2800000);
				}
				break;
			case ld::Fixup::kindLazyTarget:
			case ld::Fixup::kindIslandTarget:
				break;
			case ld::Fixup::kindSetLazyOffset:
				assert(fit->binding == ld::Fixup::bindingDirectlyBound);
				accumulator = this->lazyBindingInfoOffsetForLazyPointerAddress(fit->u.target->finalAddress());
				break;
			case ld::Fixup::kindDataInCodeStartData:
			case ld::Fixup::kindDataInCodeStartJT8:
			case ld::Fixup::kindDataInCodeStartJT16:
			case ld::Fixup::kindDataInCodeStartJT32:
			case ld::Fixup::kindDataInCodeStartJTA32:
			case ld::Fixup::kindDataInCodeEnd:
				break;
			case ld::Fixup::kindLinkerOptimizationHint:
				// expand table of address/offsets used by hints
				lohExtra.addend = fit->u.addend;
				usedByHints[fit->offsetInAtom + (lohExtra.info.delta1 << 2)] = NULL;
				if ( lohExtra.info.count > 0 )
					usedByHints[fit->offsetInAtom + (lohExtra.info.delta2 << 2)] = NULL;
				if ( lohExtra.info.count > 1 )
					usedByHints[fit->offsetInAtom + (lohExtra.info.delta3 << 2)] = NULL;
				if ( lohExtra.info.count > 2 )
					usedByHints[fit->offsetInAtom + (lohExtra.info.delta4 << 2)] = NULL;
				break;
			case ld::Fixup::kindStoreTargetAddressLittleEndian32:
				accumulator = addressOf(state, fit, &toTarget);
				thumbTarget = targetIsThumb(state, fit);
				if ( thumbTarget ) 
					accumulator |= 1;
				if ( fit->contentAddendOnly )
					accumulator = 0;
				rangeCheckAbsolute32(accumulator, state, atom, fit);
				set32LE(fixUpLocation, accumulator);
				break;
			case ld::Fixup::kindStoreTargetAddressLittleEndian64:
				accumulator = addressOf(state, fit, &toTarget);
				if ( fit->contentAddendOnly )
					accumulator = 0;
				set64LE(fixUpLocation, accumulator);
				break;
#if SUPPORT_ARCH_arm64e
			case ld::Fixup::kindStoreTargetAddressLittleEndianAuth64: {
				accumulator = addressOf(state, fit, &toTarget);
				if ( fit->contentAddendOnly ) {
					// ld -r mode.  We want to write out the original relocation again

					// FIXME: Should we zero out the accumulator here as done in kindStoreTargetAddressLittleEndian64?
					// Make sure the high bits aren't set.  The low-32-bits should be the addend.
					assert((accumulator & 0xFFFFFFFF00000000ULL) == 0);
					accumulator |= ((uint64_t)authData.discriminator) << 32;
					accumulator |= ((uint64_t)authData.hasAddressDiversity) << 48;
					accumulator |= ((uint64_t)authData.key) << 49;
					// Set the high bit as we are authenticated
					accumulator |= 1ULL << 63;
					set64LE(fixUpLocation, accumulator);
				}
				else if  (_options.outputKind() == Options::kKextBundle ) {
					// kexts dont' handle auth pointers, write unauth pointer
					set64LE(fixUpLocation, accumulator);
				}
				else {
					auto fixupOffset = (uintptr_t)(fixUpLocation - mhAddress);
					assert(_authenticatedFixupData.find(fixupOffset) == _authenticatedFixupData.end());
					auto authneticatedData = std::make_pair(authData, accumulator);
					_authenticatedFixupData[fixupOffset] = authneticatedData;
					// Zero out this entry which we will expect later.
					set64LE(fixUpLocation, 0);
				}
				break;
		   }
			case ld::Fixup::kindStoreLittleEndianAuth64: {
				if ( fit->contentAddendOnly ) {
					// ld -r mode.  We want to write out the original relocation again

					// FIXME: Should we zero out the accumulator here as done in kindStoreTargetAddressLittleEndian64?
					// Make sure the high bits aren't set.  The low-32-bits should be the addend.
					assert((accumulator & 0xFFFFFFFF00000000ULL) == 0);
					accumulator |= ((uint64_t)authData.discriminator) << 32;
					accumulator |= ((uint64_t)authData.hasAddressDiversity) << 48;
					accumulator |= ((uint64_t)authData.key) << 49;
					// Set the high bit as we are authenticated
					accumulator |= 1ULL << 63;
					set64LE(fixUpLocation, accumulator);
				}
				else if  (_options.outputKind() == Options::kKextBundle ) {
					// kexts dont' handle auth pointers, write unauth pointer
					set64LE(fixUpLocation, accumulator);
				}
				else {
					auto fixupOffset = (uintptr_t)(fixUpLocation - mhAddress);
					assert(_authenticatedFixupData.find(fixupOffset) == _authenticatedFixupData.end());
					auto authneticatedData = std::make_pair(authData, accumulator);
					_authenticatedFixupData[fixupOffset] = authneticatedData;
					// Zero out this entry which we will expect later.
					set64LE(fixUpLocation, 0);
				}
				break;
			}
			case ld::Fixup::kindSetAuthData:
				authData = fit->u.authData;
				break;
#endif
			case ld::Fixup::kindStoreTargetAddressBigEndian32:
				accumulator = addressOf(state, fit, &toTarget);
				if ( fit->contentAddendOnly )
					accumulator = 0;
				set32BE(fixUpLocation, accumulator);
				break;
			case ld::Fixup::kindStoreTargetAddressBigEndian64:
				accumulator = addressOf(state, fit, &toTarget);
				if ( fit->contentAddendOnly )
					accumulator = 0;
				set64BE(fixUpLocation, accumulator);
				break;
			case ld::Fixup::kindSetTargetTLVTemplateOffsetLittleEndian32:
				accumulator = tlvTemplateOffsetOf(state, fit);
				set32LE(fixUpLocation, accumulator);
				break;
			case ld::Fixup::kindSetTargetTLVTemplateOffsetLittleEndian64:
				accumulator = tlvTemplateOffsetOf(state, fit);
				set64LE(fixUpLocation, accumulator);
				break;
			case ld::Fixup::kindStoreTargetAddressX86PCRel32:
			case ld::Fixup::kindStoreTargetAddressX86BranchPCRel32:
			case ld::Fixup::kindStoreTargetAddressX86PCRel32GOTLoad:
			case ld::Fixup::kindStoreTargetAddressX86PCRel32TLVLoad:
				accumulator = addressOf(state, fit, &toTarget);	
				if ( fit->contentDetlaToAddendOnly )
					accumulator = 0;
				if ( fit->contentAddendOnly )
					delta = 0;
				else
					delta = accumulator - (atom->finalAddress() + fit->offsetInAtom + 4);
				rangeCheckRIP32(delta, state, atom, fit);
				set32LE(fixUpLocation, delta);
				break;
			case ld::Fixup::kindStoreTargetAddressX86Abs32TLVLoad:
				set32LE(fixUpLocation, accumulator);
				break;
			case ld::Fixup::kindStoreTargetAddressX86Abs32TLVLoadNowLEA:
				// TLV entry was optimized away, change movl instruction to a leal
				if ( fixUpLocation[-1] != 0xA1 )
					throw "TLV load reloc does not point to a movl <abs-address>,<reg> instruction";
				fixUpLocation[-1] = 0xB8;
				accumulator = addressOf(state, fit, &toTarget);
				set32LE(fixUpLocation, accumulator);
				break;
			case ld::Fixup::kindStoreTargetAddressX86PCRel32GOTLoadNowLEA:
				// GOT entry was optimized away, change movq instruction to a leaq
				if ( fixUpLocation[-2] != 0x8B )
					throw "GOT load reloc does not point to a movq instruction";
				fixUpLocation[-2] = 0x8D;
				accumulator = addressOf(state, fit, &toTarget);
				delta = accumulator - (atom->finalAddress() + fit->offsetInAtom + 4);
				rangeCheckRIP32(delta, state, atom, fit);
				set32LE(fixUpLocation, delta);
				break;
			case ld::Fixup::kindStoreTargetAddressX86PCRel32TLVLoadNowLEA:
				// TLV entry was optimized away, change movq instruction to a leaq
				if ( fixUpLocation[-2] != 0x8B )
					throw "TLV load reloc does not point to a movq instruction";
				fixUpLocation[-2] = 0x8D;
				accumulator = addressOf(state, fit, &toTarget);
				delta = accumulator - (atom->finalAddress() + fit->offsetInAtom + 4);
				rangeCheckRIP32(delta, state, atom, fit);
				set32LE(fixUpLocation, delta);
				break;
			case ld::Fixup::kindStoreTargetAddressARMBranch24:
				accumulator = addressOf(state, fit, &toTarget);
				thumbTarget = targetIsThumb(state, fit);
				if ( toTarget->contentType() == ld::Atom::typeBranchIsland ) {
					// Branching to island.  If ultimate target is in range, branch there directly.
					for (ld::Fixup::iterator islandfit = toTarget->fixupsBegin(), end=toTarget->fixupsEnd(); islandfit != end; ++islandfit) {
						if ( islandfit->kind == ld::Fixup::kindIslandTarget ) {
							const ld::Atom* islandTarget = NULL;
							uint64_t islandTargetAddress = addressOf(state, islandfit, &islandTarget);
							delta = islandTargetAddress - (atom->finalAddress() + fit->offsetInAtom + 8);
							if ( checkArmBranch24Displacement(delta) ) {
								toTarget = islandTarget;
								accumulator = islandTargetAddress;
								thumbTarget = targetIsThumb(state, islandfit);
							}
							break;
						}
					}
				}
				if ( thumbTarget ) 
					accumulator |= 1;
				if ( fit->contentDetlaToAddendOnly )
					accumulator = 0;
				// fall into kindStoreARMBranch24 case
			case ld::Fixup::kindStoreARMBranch24:
				// The pc added will be +8 from the pc
				delta = accumulator - (atom->finalAddress() + fit->offsetInAtom + 8);
				rangeCheckARMBranch24(delta, state, atom, fit);
				instruction = get32LE(fixUpLocation);
				// Make sure we are calling arm with bl, thumb with blx		
				is_bl = ((instruction & 0xFF000000) == 0xEB000000);
				is_blx = ((instruction & 0xFE000000) == 0xFA000000);
				is_b = !is_blx && ((instruction & 0x0F000000) == 0x0A000000);
				if ( (is_bl | is_blx) && thumbTarget ) {
					uint32_t opcode = 0xFA000000;  // force to be blx
					uint32_t disp = (uint32_t)(delta >> 2) & 0x00FFFFFF;
					uint32_t h_bit = (uint32_t)(delta << 23) & 0x01000000;
					newInstruction = opcode | h_bit | disp;
				} 
				else if ( (is_bl | is_blx) && !thumbTarget ) {
					uint32_t opcode = 0xEB000000;  // force to be bl
					uint32_t disp = (uint32_t)(delta >> 2) & 0x00FFFFFF;
					newInstruction = opcode | disp;
				} 
				else if ( is_b && thumbTarget ) {
					if ( fit->contentDetlaToAddendOnly )
						newInstruction = (instruction & 0xFF000000) | ((uint32_t)(delta >> 2) & 0x00FFFFFF);
					else
						throwf("no pc-rel bx arm instruction. Can't fix up branch to %s in %s",
								referenceTargetAtomName(state, fit), atom->name());
				} 
				else if ( !is_bl && !is_blx && thumbTarget ) {
					throwf("don't know how to convert instruction %x referencing %s to thumb",
						 instruction, referenceTargetAtomName(state, fit));
				}
				else {
					newInstruction = (instruction & 0xFF000000) | ((uint32_t)(delta >> 2) & 0x00FFFFFF);
				}
				set32LE(fixUpLocation, newInstruction);
				break;
			case ld::Fixup::kindStoreTargetAddressThumbBranch22:
				accumulator = addressOf(state, fit, &toTarget);
				thumbTarget = targetIsThumb(state, fit);
				if ( toTarget->contentType() == ld::Atom::typeBranchIsland ) {
					// branching to island, so see if ultimate target is in range 
					// and if so branch to ultimate target instead.
					for (ld::Fixup::iterator islandfit = toTarget->fixupsBegin(), end=toTarget->fixupsEnd(); islandfit != end; ++islandfit) {
						if ( islandfit->kind == ld::Fixup::kindIslandTarget ) {
							const ld::Atom* islandTarget = NULL;
							uint64_t islandTargetAddress = addressOf(state, islandfit, &islandTarget);
							if ( !fit->contentDetlaToAddendOnly ) {
								if ( targetIsThumb(state, islandfit) ) {
									// Thumb to thumb branch, we will be generating a bl instruction.
									// Delta is always even, so mask out thumb bit in target.
									islandTargetAddress &= -2ULL;
								}
								else {
									// Target is not thumb, we will be generating a blx instruction
									// Since blx cannot have the low bit set, set bit[1] of the target to
									// bit[1] of the base address, so that the difference is a multiple of
									// 4 bytes.
									islandTargetAddress &= -3ULL;
									islandTargetAddress |= ((atom->finalAddress() + fit->offsetInAtom ) & 2LL);
								}
							}
							delta = islandTargetAddress - (atom->finalAddress() + fit->offsetInAtom + 4);
							if ( checkThumbBranch22Displacement(delta) ) {
								toTarget = islandTarget;
								accumulator = islandTargetAddress;
								thumbTarget = targetIsThumb(state, islandfit);
							}
							break;
						}
					}
				}
				if ( thumbTarget ) 
					accumulator |= 1;
				if ( fit->contentDetlaToAddendOnly )
					accumulator = 0;
				// fall into kindStoreThumbBranch22 case
			case ld::Fixup::kindStoreThumbBranch22:
				instruction = get32LE(fixUpLocation);
				is_bl = ((instruction & 0xD000F800) == 0xD000F000);
				is_blx = ((instruction & 0xD000F800) == 0xC000F000);
				is_b = ((instruction & 0xD000F800) == 0x9000F000);
				if ( !fit->contentDetlaToAddendOnly ) {
					if ( thumbTarget ) {
						// Thumb to thumb branch, we will be generating a bl instruction.
						// Delta is always even, so mask out thumb bit in target.
						accumulator &= -2ULL;
					}
					else {
						// Target is not thumb, we will be generating a blx instruction
						// Since blx cannot have the low bit set, set bit[1] of the target to
						// bit[1] of the base address, so that the difference is a multiple of
						// 4 bytes.
						accumulator &= -3ULL;
						accumulator |= ((atom->finalAddress() + fit->offsetInAtom ) & 2LL);
					}
				}
				// The pc added will be +4 from the pc
				delta = accumulator - (atom->finalAddress() + fit->offsetInAtom + 4);
				// <rdar://problem/16652542> support bl in very large .o files
				if ( fit->contentDetlaToAddendOnly ) {
					while ( delta < (-16777216LL) ) 
						delta += 0x2000000;
				}
				rangeCheckThumbBranch22(delta, state, atom, fit);
				if ( _options.preferSubArchitecture() && _options.archSupportsThumb2() ) {
					// The instruction is really two instructions:
					// The lower 16 bits are the first instruction, which contains the high
					//   11 bits of the displacement.
					// The upper 16 bits are the second instruction, which contains the low
					//   11 bits of the displacement, as well as differentiating bl and blx.
					uint32_t s = (uint32_t)(delta >> 24) & 0x1;
					uint32_t i1 = (uint32_t)(delta >> 23) & 0x1;
					uint32_t i2 = (uint32_t)(delta >> 22) & 0x1;
					uint32_t imm10 = (uint32_t)(delta >> 12) & 0x3FF;
					uint32_t imm11 = (uint32_t)(delta >> 1) & 0x7FF;
					uint32_t j1 = (i1 == s);
					uint32_t j2 = (i2 == s);
					if ( is_bl ) {
						if ( thumbTarget )
							instruction = 0xD000F000; // keep bl
						else
							instruction = 0xC000F000; // change to blx
					} 
					else if ( is_blx ) {
						if ( thumbTarget )
							instruction = 0xD000F000; // change to bl
						else
							instruction = 0xC000F000; // keep blx
					}
					else if ( is_b ) {
						instruction = 0x9000F000; // keep b
						if ( !thumbTarget && !fit->contentDetlaToAddendOnly ) {
							throwf("armv7 has no pc-rel bx thumb instruction. Can't fix up branch to %s in %s",
									referenceTargetAtomName(state, fit), atom->name());
						}
					} 
					else {
						if ( !thumbTarget ) 
							throwf("don't know how to convert branch instruction %x referencing %s to bx",
									instruction, referenceTargetAtomName(state, fit));
						instruction = 0x9000F000; // keep b
					} 
					uint32_t nextDisp = (j1 << 13) | (j2 << 11) | imm11;
					uint32_t firstDisp = (s << 10) | imm10;
					newInstruction = instruction | (nextDisp << 16) | firstDisp;
					//warning("s=%d, j1=%d, j2=%d, imm10=0x%0X, imm11=0x%0X, instruction=0x%08X, first=0x%04X, next=0x%04X, new=0x%08X, disp=0x%llX for %s to %s\n",
					//	s, j1, j2, imm10, imm11, instruction, firstDisp, nextDisp, newInstruction, delta, atom->name(), toTarget->name());
					set32LE(fixUpLocation, newInstruction);				
				}
				else {
					// The instruction is really two instructions:
					// The lower 16 bits are the first instruction, which contains the high
					//   11 bits of the displacement.
					// The upper 16 bits are the second instruction, which contains the low
					//   11 bits of the displacement, as well as differentiating bl and blx.
					uint32_t firstDisp = (uint32_t)(delta >> 12) & 0x7FF;
					uint32_t nextDisp = (uint32_t)(delta >> 1) & 0x7FF;
					if ( is_bl && !thumbTarget ) {
						instruction = 0xE800F000;
					} 
					else if ( is_blx && thumbTarget ) {
						instruction = 0xF800F000;
					} 
					else if ( is_b ) {
						instruction = 0x9000F000; // keep b
						if ( !thumbTarget && !fit->contentDetlaToAddendOnly ) {
							throwf("armv6 has no pc-rel bx thumb instruction. Can't fix up branch to %s in %s",
									referenceTargetAtomName(state, fit), atom->name());
						}
					}
					else {
						instruction = instruction & 0xF800F800;
					}
					newInstruction = instruction | (nextDisp << 16) | firstDisp;
					set32LE(fixUpLocation, newInstruction);				
				}
				break;
			case ld::Fixup::kindStoreARMLow16:
				{
					uint32_t imm4 = (accumulator & 0x0000F000) >> 12;
					uint32_t imm12 = accumulator & 0x00000FFF;
					instruction = get32LE(fixUpLocation);
					newInstruction = (instruction & 0xFFF0F000) | (imm4 << 16) | imm12;
					set32LE(fixUpLocation, newInstruction);		
				}
				break;
			case ld::Fixup::kindStoreARMHigh16:
				{
					uint32_t imm4  = (accumulator & 0xF0000000) >> 28;
					uint32_t imm12 = (accumulator & 0x0FFF0000) >> 16;
					instruction = get32LE(fixUpLocation);
					newInstruction = (instruction & 0xFFF0F000) | (imm4 << 16) | imm12;
					set32LE(fixUpLocation, newInstruction);		
				}
				break;
			case ld::Fixup::kindStoreThumbLow16:
				{
					uint32_t imm4 = (accumulator & 0x0000F000) >> 12;
					uint32_t i =    (accumulator & 0x00000800) >> 11;
					uint32_t imm3 = (accumulator & 0x00000700) >> 8;
					uint32_t imm8 =  accumulator & 0x000000FF;
					instruction = get32LE(fixUpLocation);
					newInstruction = (instruction & 0x8F00FBF0) | imm4 | (i << 10) | (imm3 << 28) | (imm8 << 16);
					set32LE(fixUpLocation, newInstruction);		
				}
				break;
			case ld::Fixup::kindStoreThumbHigh16:
				{
					uint32_t imm4 = (accumulator & 0xF0000000) >> 28;
					uint32_t i =    (accumulator & 0x08000000) >> 27;
					uint32_t imm3 = (accumulator & 0x07000000) >> 24;
					uint32_t imm8 = (accumulator & 0x00FF0000) >> 16;
					instruction = get32LE(fixUpLocation);
					newInstruction = (instruction & 0x8F00FBF0) | imm4 | (i << 10) | (imm3 << 28) | (imm8 << 16);
					set32LE(fixUpLocation, newInstruction);		
				}
				break;
#if SUPPORT_ARCH_arm64
			case ld::Fixup::kindStoreTargetAddressARM64Branch26:
				accumulator = addressOf(state, fit, &toTarget);
				// fall into kindStoreARM64Branch26 case
			case ld::Fixup::kindStoreARM64Branch26:
				if ( fit->contentAddendOnly )
					delta = accumulator;
				else
                    delta = accumulator - (atom->finalAddress() + fit->offsetInAtom);
				rangeCheckARM64Branch26(delta, state, atom, fit);
				instruction = get32LE(fixUpLocation);
				newInstruction = (instruction & 0xFC000000) | ((uint32_t)(delta >> 2) & 0x03FFFFFF);
				set32LE(fixUpLocation, newInstruction);
				break;
			case ld::Fixup::kindStoreTargetAddressARM64GOTLeaPage21:
			case ld::Fixup::kindStoreTargetAddressARM64GOTLoadPage21:
			case ld::Fixup::kindStoreTargetAddressARM64Page21:
			case ld::Fixup::kindStoreTargetAddressARM64TLVPLoadPage21:
			case ld::Fixup::kindStoreTargetAddressARM64TLVPLoadNowLeaPage21:
				accumulator = addressOf(state, fit, &toTarget);
				// fall into kindStoreARM64Branch26 case
			case ld::Fixup::kindStoreARM64GOTLeaPage21:
			case ld::Fixup::kindStoreARM64GOTLoadPage21:
			case ld::Fixup::kindStoreARM64TLVPLoadPage21:
			case ld::Fixup::kindStoreARM64TLVPLoadNowLeaPage21:
			case ld::Fixup::kindStoreARM64Page21:
				{
					// the ADRP instruction adds the imm << 12 to the page that the pc is on
					if ( fit->contentAddendOnly )
						delta = 0;
					else
						delta = (accumulator & (-4096)) - ((atom->finalAddress() + fit->offsetInAtom) & (-4096));
					rangeCheckARM64Page21(delta, state, atom, fit);
					instruction = get32LE(fixUpLocation);
					uint32_t immhi = (delta >> 9) & (0x00FFFFE0);
					uint32_t immlo = (delta << 17) & (0x60000000);
					newInstruction = (instruction & 0x9F00001F) | immlo | immhi;
					set32LE(fixUpLocation, newInstruction);
				}
				break;
			case ld::Fixup::kindStoreTargetAddressARM64GOTLoadPageOff12:
				// In -r mode, the GOT doesn't exist but the relocations track it
				// so the address doesn't need to be aligned.
				if ( _options.outputKind() == Options::kObjectFile )
					break;
			case ld::Fixup::kindStoreTargetAddressARM64PageOff12:
			case ld::Fixup::kindStoreTargetAddressARM64TLVPLoadPageOff12:
				accumulator = addressOf(state, fit, &toTarget);
				// fall into kindAddressARM64PageOff12 case
			case ld::Fixup::kindStoreARM64TLVPLoadPageOff12:
			case ld::Fixup::kindStoreARM64GOTLoadPageOff12:
			case ld::Fixup::kindStoreARM64PageOff12:
				{
					uint32_t offset = accumulator & 0x00000FFF;
					instruction = get32LE(fixUpLocation);
					// LDR/STR instruction have implicit scale factor, need to compensate for that
					if ( instruction & 0x08000000 ) {
						uint32_t implictShift = ((instruction >> 30) & 0x3);
						switch ( implictShift ) {
							case 0:
								if ( (instruction & 0x04800000) == 0x04800000 ) {
									// vector and byte LDR/STR have same "size" bits, need to check other bits to differenciate
									implictShift = 4;
									if ( (offset & 0xF) != 0 ) {
											throwf("128-bit LDR/STR not 16-byte aligned: from %s (0x%08llX) to %s (0x%08llX)", 
												atom->name(), atom->finalAddress(), referenceTargetAtomName(state, fit), 
												addressOf(state, fit, &toTarget));
									}
								}
								break;
							case 1:
								if ( (offset & 0x1) != 0 ) {
										throwf("16-bit LDR/STR not 2-byte aligned: from %s (0x%08llX) to %s (0x%08llX)", 
											atom->name(), atom->finalAddress(), referenceTargetAtomName(state, fit), 
											addressOf(state, fit, &toTarget));
								}
								break;
							case 2:
								if ( (offset & 0x3) != 0 ) {
										throwf("32-bit LDR/STR not 4-byte aligned: from %s (0x%08llX) to %s (0x%08llX)", 
											atom->name(), atom->finalAddress(), referenceTargetAtomName(state, fit), 
											addressOf(state, fit, &toTarget));
								}
								break;
							case 3:
								if ( (offset & 0x7) != 0 ) {
										throwf("64-bit LDR/STR not 8-byte aligned: from %s (0x%08llX) to %s (0x%08llX)", 
											atom->name(), atom->finalAddress(), referenceTargetAtomName(state, fit), 
											addressOf(state, fit, &toTarget));
								}
								break;
						}
						// compensate for implicit scale
						offset >>= implictShift;
					}
					if ( fit->contentAddendOnly )
						offset = 0;
					uint32_t imm12 = offset << 10;
					newInstruction = (instruction & 0xFFC003FF) | imm12;
					set32LE(fixUpLocation, newInstruction);
				}
				break;
			case ld::Fixup::kindStoreTargetAddressARM64GOTLeaPageOff12:
				accumulator = addressOf(state, fit, &toTarget);
				// fall into kindStoreARM64GOTLoadPage21 case
			case ld::Fixup::kindStoreARM64GOTLeaPageOff12:
				{
					// GOT entry was optimized away, change LDR instruction to a ADD
					instruction = get32LE(fixUpLocation);
					if ( (instruction & 0xBFC00000) != 0xB9400000 )
						throwf("GOT load reloc does not point to a LDR instruction in %s", atom->name());
					uint32_t offset = accumulator & 0x00000FFF;
					uint32_t imm12 = offset << 10;
					newInstruction = 0x91000000 | imm12 | (instruction & 0x000003FF);
					set32LE(fixUpLocation, newInstruction);
				}
				break;
			case ld::Fixup::kindStoreTargetAddressARM64TLVPLoadNowLeaPageOff12:
				accumulator = addressOf(state, fit, &toTarget);
				// fall into kindStoreARM64TLVPLeaPageOff12 case
			case ld::Fixup::kindStoreARM64TLVPLoadNowLeaPageOff12:
				{
					// TLV thunk in same linkage unit, so LEA it directly, changing LDR instruction to a ADD
					instruction = get32LE(fixUpLocation);
					if ( (instruction & 0xBFC00000) != 0xB9400000 )
						throwf("TLV load reloc does not point to a LDR instruction in %s", atom->name());
					uint32_t offset = accumulator & 0x00000FFF;
					uint32_t imm12 = offset << 10;
					newInstruction = 0x91000000 | imm12 | (instruction & 0x000003FF);
					set32LE(fixUpLocation, newInstruction);
				}
				break;
			case ld::Fixup::kindStoreARM64PointerToGOT:
				set64LE(fixUpLocation, accumulator);
				break;
        case ld::Fixup::kindStoreARM64PCRelToGOT:
				if ( fit->contentAddendOnly )
					delta = accumulator;
				else
					delta = accumulator - (atom->finalAddress() + fit->offsetInAtom);
				set32LE(fixUpLocation, delta);
				break;
#endif
		}
	}
	
#if SUPPORT_ARCH_arm64
	// after all fixups are done on atom, if there are potential optimizations, do those
	if ( (usedByHints.size() != 0) && (_options.outputKind() != Options::kObjectFile) && !_options.ignoreOptimizationHints() ) {
		// fill in second part of usedByHints map, so we can see the target of fixups that might be optimized
		for (ld::Fixup::iterator fit = atom->fixupsBegin(), end=atom->fixupsEnd(); fit != end; ++fit) {
			switch ( fit->kind ) {
				case ld::Fixup::kindLinkerOptimizationHint:
				case ld::Fixup::kindNoneFollowOn:
				case ld::Fixup::kindNoneGroupSubordinate:
				case ld::Fixup::kindNoneGroupSubordinateFDE:
				case ld::Fixup::kindNoneGroupSubordinateLSDA:
				case ld::Fixup::kindNoneGroupSubordinatePersonality:
					break;
				default:
					if ( fit->firstInCluster() ) {
						std::map<uint32_t, const Fixup*>::iterator pos = usedByHints.find(fit->offsetInAtom);
						if ( pos != usedByHints.end() ) {
							assert(pos->second == NULL && "two fixups in same hint location");
							pos->second = fit;
							//fprintf(stderr, "setting %s usedByHints[0x%04X], kind = %d\n",  atom->name(), fit->offsetInAtom, fit->kind);
						}
					}
			}
		}
		
		// apply hints pass 1
		for (ld::Fixup::iterator fit = atom->fixupsBegin(), end=atom->fixupsEnd(); fit != end; ++fit) {
			if ( fit->kind != ld::Fixup::kindLinkerOptimizationHint ) 
				continue;
			InstructionInfo infoA;
			InstructionInfo infoB;
			InstructionInfo infoC;
			InstructionInfo infoD;
			LoadStoreInfo ldrInfoB, ldrInfoC;
			AddInfo addInfoB;
			AdrpInfo adrpInfoA;
			bool usableSegment;
			bool targetFourByteAligned;
			bool literalableSize, isADRP, isADD, isLDR, isSTR;
			//uint8_t loadSize, destReg;
			//uint32_t scaledOffset;
			//uint32_t imm12;
			ld::Fixup::LOH_arm64 alt;
			alt.addend = fit->u.addend;
			setInfo(state, atom, buffer, usedByHints, fit->offsetInAtom, (alt.info.delta1 << 2), &infoA);
			if ( alt.info.count > 0 ) 
				setInfo(state, atom, buffer, usedByHints, fit->offsetInAtom, (alt.info.delta2 << 2), &infoB);
			if ( alt.info.count > 1 )
				setInfo(state, atom, buffer, usedByHints, fit->offsetInAtom, (alt.info.delta3 << 2), &infoC);
			if ( alt.info.count > 2 )
				setInfo(state, atom, buffer, usedByHints, fit->offsetInAtom, (alt.info.delta4 << 2), &infoD);

			if ( _options.sharedRegionEligible() ) {
				if ( _options.sharedRegionEncodingV2() ) {
					// In v2 format, all references might be move at dyld shared cache creation time
					usableSegment = false;
				}
				else {
					// In v1 format, only references to something in __TEXT segment could be optimized
					usableSegment = (strcmp(atom->section().segmentName(), infoB.target->section().segmentName()) == 0);
				}
			}
			else {
				// main executables can optimize any reference
				usableSegment = true;
			}

			switch ( alt.info.kind ) {
				case LOH_ARM64_ADRP_ADRP:
					// processed in pass 2 because some ADRP may have been removed
					break;
				case LOH_ARM64_ADRP_LDR:
					LOH_ASSERT(alt.info.count == 1);
					LOH_ASSERT(isPageKind(infoA.fixup));
					LOH_ASSERT(isPageOffsetKind(infoB.fixup));
					LOH_ASSERT(infoA.target == infoB.target);
					LOH_ASSERT(infoA.targetAddress == infoB.targetAddress);
					isADRP = parseADRP(infoA.instruction, adrpInfoA);
					LOH_ASSERT(isADRP);
					isLDR = parseLoadOrStore(infoB.instruction, ldrInfoB);
					// silently ignore LDRs transformed to ADD by TLV pass
					if ( !isLDR && infoB.fixup->kind == ld::Fixup::kindStoreTargetAddressARM64TLVPLoadNowLeaPageOff12 )
						break;
					LOH_ASSERT(isLDR);
					LOH_ASSERT(ldrInfoB.baseReg == adrpInfoA.destReg);
					LOH_ASSERT(ldrInfoB.offset == (infoA.targetAddress & 0x00000FFF));
					literalableSize = ( (ldrInfoB.size != 1) && (ldrInfoB.size != 2) );
					targetFourByteAligned = ( (infoA.targetAddress & 0x3) == 0 );
					if ( literalableSize && usableSegment && targetFourByteAligned && withinOneMeg(infoB.instructionAddress, infoA.targetAddress) ) {
						set32LE(infoA.instructionContent, makeNOP());
						set32LE(infoB.instructionContent, makeLDR_literal(ldrInfoB, infoA.targetAddress, infoB.instructionAddress));
						if ( _options.verboseOptimizationHints() )
							fprintf(stderr, "adrp-ldr at 0x%08llX transformed to LDR literal, usableSegment=%d usableSegment\n", infoB.instructionAddress, usableSegment);
					}
					else {
						if ( _options.verboseOptimizationHints() )
							fprintf(stderr, "adrp-ldr at 0x%08llX not transformed, isLDR=%d, literalableSize=%d, inRange=%d, usableSegment=%d, scaledOffset=%d\n", 
								infoB.instructionAddress, isLDR, literalableSize, withinOneMeg(infoB.instructionAddress, infoA.targetAddress), usableSegment, ldrInfoB.offset);
					}
					break;
				case LOH_ARM64_ADRP_ADD_LDR:
					LOH_ASSERT(alt.info.count == 2);
					LOH_ASSERT(isPageKind(infoA.fixup));
					LOH_ASSERT(isPageOffsetKind(infoB.fixup));
					LOH_ASSERT(infoC.fixup == NULL);
					LOH_ASSERT(infoA.target == infoB.target);
					LOH_ASSERT(infoA.targetAddress == infoB.targetAddress);
					isADRP = parseADRP(infoA.instruction, adrpInfoA);
					LOH_ASSERT(isADRP);
					isADD = parseADD(infoB.instruction, addInfoB);
					LOH_ASSERT(isADD);
					LOH_ASSERT(adrpInfoA.destReg == addInfoB.srcReg);
					isLDR = parseLoadOrStore(infoC.instruction, ldrInfoC);
					LOH_ASSERT(isLDR);
					LOH_ASSERT(addInfoB.destReg == ldrInfoC.baseReg);
					targetFourByteAligned = ( ((infoB.targetAddress+ldrInfoC.offset) & 0x3) == 0 );
					literalableSize  = ( (ldrInfoC.size != 1) && (ldrInfoC.size != 2) );
					if ( literalableSize && usableSegment && targetFourByteAligned && withinOneMeg(infoC.instructionAddress, infoA.targetAddress+ldrInfoC.offset) ) {
						// can do T1 transformation to LDR literal
						set32LE(infoA.instructionContent, makeNOP());
						set32LE(infoB.instructionContent, makeNOP());
						set32LE(infoC.instructionContent, makeLDR_literal(ldrInfoC, infoA.targetAddress+ldrInfoC.offset, infoC.instructionAddress));
						if ( _options.verboseOptimizationHints() ) {
							fprintf(stderr, "adrp-add-ldr at 0x%08llX T1 transformed to LDR literal\n", infoC.instructionAddress);
						}
					}
					else if ( usableSegment && withinOneMeg(infoA.instructionAddress, infoA.targetAddress+ldrInfoC.offset) ) {
						// can to T4 transformation and turn ADRP/ADD into ADR
						set32LE(infoA.instructionContent, makeADR(ldrInfoC.baseReg, infoA.targetAddress+ldrInfoC.offset, infoA.instructionAddress));
						set32LE(infoB.instructionContent, makeNOP());	
						ldrInfoC.offset = 0; // offset is now in ADR instead of ADD or LDR
						set32LE(infoC.instructionContent, makeLoadOrStore(ldrInfoC));
						set32LE(infoC.instructionContent, infoC.instruction & 0xFFC003FF);	
						if ( _options.verboseOptimizationHints() )
							fprintf(stderr, "adrp-add-ldr at 0x%08llX T4 transformed to ADR/LDR\n", infoB.instructionAddress);						
					}
					else if ( ((infoB.targetAddress % ldrInfoC.size) == 0) && (ldrInfoC.offset == 0) ) {
						// can do T2 transformation by merging ADD into LD
						// Leave ADRP as-is
						set32LE(infoB.instructionContent, makeNOP());	
						ldrInfoC.offset += addInfoB.addend;
						ldrInfoC.baseReg = adrpInfoA.destReg;
						set32LE(infoC.instructionContent, makeLoadOrStore(ldrInfoC));
						if ( _options.verboseOptimizationHints() )
							fprintf(stderr, "adrp-add-ldr at 0x%08llX T2 transformed to ADRP/LDR \n", infoC.instructionAddress);
					}
					else {
						if ( _options.verboseOptimizationHints() )
							fprintf(stderr, "adrp-add-ldr at 0x%08llX could not be transformed, loadSize=%d, literalableSize=%d, inRange=%d, usableSegment=%d, targetFourByteAligned=%d, imm12=%d\n", 
									infoC.instructionAddress, ldrInfoC.size, literalableSize, withinOneMeg(infoC.instructionAddress, infoA.targetAddress+ldrInfoC.offset), usableSegment, targetFourByteAligned, ldrInfoC.offset);
					}
					break;
				case LOH_ARM64_ADRP_ADD:
					LOH_ASSERT(alt.info.count == 1);
					LOH_ASSERT(isPageKind(infoA.fixup));
					LOH_ASSERT(isPageOffsetKind(infoB.fixup));
					LOH_ASSERT(infoA.target == infoB.target);
					LOH_ASSERT(infoA.targetAddress == infoB.targetAddress);
					isADRP = parseADRP(infoA.instruction, adrpInfoA);
					LOH_ASSERT(isADRP);
					isADD = parseADD(infoB.instruction, addInfoB);
					LOH_ASSERT(isADD);
					LOH_ASSERT(adrpInfoA.destReg == addInfoB.srcReg);
					if ( usableSegment && withinOneMeg(infoA.targetAddress, infoA.instructionAddress) ) {
						// can do T4 transformation and use ADR 
						set32LE(infoA.instructionContent, makeADR(addInfoB.destReg, infoA.targetAddress, infoA.instructionAddress));
						set32LE(infoB.instructionContent, makeNOP());	
						if ( _options.verboseOptimizationHints() )
							fprintf(stderr, "adrp-add at 0x%08llX transformed to ADR\n", infoB.instructionAddress);
					}
					else {
						if ( _options.verboseOptimizationHints() )
							fprintf(stderr, "adrp-add at 0x%08llX not transformed, isAdd=%d, inRange=%d, usableSegment=%d\n", 
								infoB.instructionAddress, isADD, withinOneMeg(infoA.targetAddress, infoA.instructionAddress), usableSegment);
					}
					break;
				case LOH_ARM64_ADRP_LDR_GOT_LDR:
					LOH_ASSERT(alt.info.count == 2);
					LOH_ASSERT(isPageKind(infoA.fixup, true));
					LOH_ASSERT(isPageOffsetKind(infoB.fixup, true));
					LOH_ASSERT(infoC.fixup == NULL);
					LOH_ASSERT(infoA.target == infoB.target);
					LOH_ASSERT(infoA.targetAddress == infoB.targetAddress);
					isADRP = parseADRP(infoA.instruction, adrpInfoA);
					LOH_ASSERT(isADRP);
					isLDR = parseLoadOrStore(infoC.instruction, ldrInfoC);
					LOH_ASSERT(isLDR);
					isADD = parseADD(infoB.instruction, addInfoB);
					isLDR = parseLoadOrStore(infoB.instruction, ldrInfoB);
					if ( isLDR ) {
						// target of GOT is external
						LOH_ASSERT(ldrInfoB.size == 8);
						LOH_ASSERT(!ldrInfoB.isFloat);
						LOH_ASSERT(ldrInfoC.baseReg == ldrInfoB.reg);
						//fprintf(stderr, "infoA.target=%p, %s, infoA.targetAddress=0x%08llX\n", infoA.target, infoA.target->name(), infoA.targetAddress);
						targetFourByteAligned = ( ((infoA.targetAddress + ldrInfoC.offset) & 0x3) == 0 );
						if ( usableSegment && targetFourByteAligned && withinOneMeg(infoB.instructionAddress, infoA.targetAddress + ldrInfoC.offset) ) {
							// can do T5 transform
							set32LE(infoA.instructionContent, makeNOP());
							set32LE(infoB.instructionContent, makeLDR_literal(ldrInfoB, infoA.targetAddress, infoB.instructionAddress));
							if ( _options.verboseOptimizationHints() ) {
								fprintf(stderr, "adrp-ldr-got-ldr at 0x%08llX T5 transformed to LDR literal of GOT plus LDR\n", infoC.instructionAddress);
							}
						}
						else {
							if ( _options.verboseOptimizationHints() ) 
								fprintf(stderr, "adrp-ldr-got-ldr at 0x%08llX no optimization done\n", infoC.instructionAddress);
						}
					}
					else if ( isADD ) {
						// target of GOT is in same linkage unit and B instruction was changed to ADD to compute LEA of target
						LOH_ASSERT(addInfoB.srcReg == adrpInfoA.destReg);
						LOH_ASSERT(addInfoB.destReg == ldrInfoC.baseReg);
						targetFourByteAligned = ( ((infoA.targetAddress) & 0x3) == 0 );
						literalableSize  = ( (ldrInfoC.size != 1) && (ldrInfoC.size != 2) );
						if ( usableSegment && literalableSize && targetFourByteAligned && withinOneMeg(infoC.instructionAddress, infoA.targetAddress + ldrInfoC.offset) ) {
							// can do T1 transform
							set32LE(infoA.instructionContent, makeNOP());	
							set32LE(infoB.instructionContent, makeNOP());	
							set32LE(infoC.instructionContent, makeLDR_literal(ldrInfoC, infoA.targetAddress + ldrInfoC.offset, infoC.instructionAddress));
							if ( _options.verboseOptimizationHints() ) 
								fprintf(stderr, "adrp-ldr-got-ldr at 0x%08llX T1 transformed to LDR literal\n", infoC.instructionAddress);
						}
						else if ( usableSegment && withinOneMeg(infoA.instructionAddress, infoA.targetAddress) ) {
							// can do T4 transform
							set32LE(infoA.instructionContent, makeADR(ldrInfoC.baseReg, infoA.targetAddress, infoA.instructionAddress));
							set32LE(infoB.instructionContent, makeNOP());	
							set32LE(infoC.instructionContent, makeLoadOrStore(ldrInfoC));
							if ( _options.verboseOptimizationHints() ) {
								fprintf(stderr, "adrp-ldr-got-ldr at 0x%08llX T4 transformed to ADR/LDR\n", infoC.instructionAddress);
							}
						}
						else if ( ((infoA.targetAddress % ldrInfoC.size) == 0) && ((addInfoB.addend + ldrInfoC.offset) < 4096) ) {
							// can do T2 transform
							set32LE(infoB.instructionContent, makeNOP());
							ldrInfoC.baseReg = adrpInfoA.destReg;
							ldrInfoC.offset += addInfoB.addend;
							set32LE(infoC.instructionContent, makeLoadOrStore(ldrInfoC));
							if ( _options.verboseOptimizationHints() ) {
								fprintf(stderr, "adrp-ldr-got-ldr at 0x%08llX T2 transformed to ADRP/NOP/LDR\n", infoC.instructionAddress);
							}
						}
						else {
							// T3 transform already done by ld::passes:got:doPass()
							if ( _options.verboseOptimizationHints() ) {
								fprintf(stderr, "adrp-ldr-got-ldr at 0x%08llX T3 transformed to ADRP/ADD/LDR\n", infoC.instructionAddress);
							}
						}
					}
					else {
						if ( _options.verboseOptimizationHints() ) 							
							fprintf(stderr, "adrp-ldr-got-ldr at 0x%08llX not ADD or LDR\n", infoC.instructionAddress);
					}
					break;
				case LOH_ARM64_ADRP_ADD_STR:
					LOH_ASSERT(alt.info.count == 2);
					LOH_ASSERT(isPageKind(infoA.fixup));
					LOH_ASSERT(isPageOffsetKind(infoB.fixup));
					LOH_ASSERT(infoC.fixup == NULL);
					LOH_ASSERT(infoA.target == infoB.target);
					LOH_ASSERT(infoA.targetAddress == infoB.targetAddress);
					isADRP = parseADRP(infoA.instruction, adrpInfoA);
					LOH_ASSERT(isADRP);
					isADD = parseADD(infoB.instruction, addInfoB);
					LOH_ASSERT(isADD);
					LOH_ASSERT(adrpInfoA.destReg == addInfoB.srcReg);
					isSTR = (parseLoadOrStore(infoC.instruction, ldrInfoC) && ldrInfoC.isStore);
					LOH_ASSERT(isSTR);
					LOH_ASSERT(addInfoB.destReg == ldrInfoC.baseReg);
					if ( usableSegment && withinOneMeg(infoA.instructionAddress, infoA.targetAddress+ldrInfoC.offset) ) {
						// can to T4 transformation and turn ADRP/ADD into ADR
						set32LE(infoA.instructionContent, makeADR(ldrInfoC.baseReg, infoA.targetAddress+ldrInfoC.offset, infoA.instructionAddress));
						set32LE(infoB.instructionContent, makeNOP());	
						ldrInfoC.offset = 0; // offset is now in ADR instead of ADD or LDR
						set32LE(infoC.instructionContent, makeLoadOrStore(ldrInfoC));
						set32LE(infoC.instructionContent, infoC.instruction & 0xFFC003FF);	
						if ( _options.verboseOptimizationHints() )
							fprintf(stderr, "adrp-add-str at 0x%08llX T4 transformed to ADR/STR\n", infoB.instructionAddress);						
					}
					else if ( ((infoB.targetAddress % ldrInfoC.size) == 0) && (ldrInfoC.offset == 0) ) {
						// can do T2 transformation by merging ADD into STR
						// Leave ADRP as-is
						set32LE(infoB.instructionContent, makeNOP());	
						ldrInfoC.offset += addInfoB.addend;
						set32LE(infoC.instructionContent, makeLoadOrStore(ldrInfoC));
						if ( _options.verboseOptimizationHints() )
							fprintf(stderr, "adrp-add-str at 0x%08llX T2 transformed to ADRP/STR \n", infoC.instructionAddress);
					}
					else {
						if ( _options.verboseOptimizationHints() )
							fprintf(stderr, "adrp-add-str at 0x%08llX could not be transformed, loadSize=%d, inRange=%d, usableSegment=%d, imm12=%d\n", 
									infoC.instructionAddress, ldrInfoC.size, withinOneMeg(infoC.instructionAddress, infoA.targetAddress+ldrInfoC.offset), usableSegment, ldrInfoC.offset);
					}
					break;
				case LOH_ARM64_ADRP_LDR_GOT_STR:
					LOH_ASSERT(alt.info.count == 2);
					LOH_ASSERT(isPageKind(infoA.fixup, true));
					LOH_ASSERT(isPageOffsetKind(infoB.fixup, true));
					LOH_ASSERT(infoC.fixup == NULL);
					LOH_ASSERT(infoA.target == infoB.target);
					LOH_ASSERT(infoA.targetAddress == infoB.targetAddress);
					isADRP = parseADRP(infoA.instruction, adrpInfoA);
					LOH_ASSERT(isADRP);
					isSTR = (parseLoadOrStore(infoC.instruction, ldrInfoC) && ldrInfoC.isStore);
					LOH_ASSERT(isSTR);
					isADD = parseADD(infoB.instruction, addInfoB);
					isLDR = parseLoadOrStore(infoB.instruction, ldrInfoB);
					if ( isLDR ) {
						// target of GOT is external
						LOH_ASSERT(ldrInfoB.size == 8);
						LOH_ASSERT(!ldrInfoB.isFloat);
						LOH_ASSERT(ldrInfoC.baseReg == ldrInfoB.reg);
						targetFourByteAligned = ( ((infoA.targetAddress + ldrInfoC.offset) & 0x3) == 0 );
						if ( usableSegment && targetFourByteAligned && withinOneMeg(infoB.instructionAddress, infoA.targetAddress + ldrInfoC.offset) ) {
							// can do T5 transform
							set32LE(infoA.instructionContent, makeNOP());
							set32LE(infoB.instructionContent, makeLDR_literal(ldrInfoB, infoA.targetAddress, infoB.instructionAddress));
							if ( _options.verboseOptimizationHints() ) {
								fprintf(stderr, "adrp-ldr-got-str at 0x%08llX T5 transformed to LDR literal of GOT plus STR\n", infoC.instructionAddress);
							}
						}
						else {
							if ( _options.verboseOptimizationHints() ) 
								fprintf(stderr, "adrp-ldr-got-str at 0x%08llX no optimization done\n", infoC.instructionAddress);
						}
					}
					else if ( isADD ) {
						// target of GOT is in same linkage unit and B instruction was changed to ADD to compute LEA of target
						LOH_ASSERT(addInfoB.srcReg == adrpInfoA.destReg);
						LOH_ASSERT(addInfoB.destReg == ldrInfoC.baseReg);
						targetFourByteAligned = ( ((infoA.targetAddress) & 0x3) == 0 );
						literalableSize  = ( (ldrInfoC.size != 1) && (ldrInfoC.size != 2) );
						if ( usableSegment && withinOneMeg(infoA.instructionAddress, infoA.targetAddress) ) {
							// can do T4 transform
							set32LE(infoA.instructionContent, makeADR(ldrInfoC.baseReg, infoA.targetAddress, infoA.instructionAddress));
							set32LE(infoB.instructionContent, makeNOP());	
							set32LE(infoC.instructionContent, makeLoadOrStore(ldrInfoC));
							if ( _options.verboseOptimizationHints() ) {
								fprintf(stderr, "adrp-ldr-got-str at 0x%08llX T4 transformed to ADR/STR\n", infoC.instructionAddress);
							}
						}
						else if ( ((infoA.targetAddress % ldrInfoC.size) == 0) && (ldrInfoC.offset == 0) ) {
							// can do T2 transform
							set32LE(infoB.instructionContent, makeNOP());
							ldrInfoC.baseReg = adrpInfoA.destReg;
							ldrInfoC.offset += addInfoB.addend;
							set32LE(infoC.instructionContent, makeLoadOrStore(ldrInfoC));
							if ( _options.verboseOptimizationHints() ) {
								fprintf(stderr, "adrp-ldr-got-str at 0x%08llX T4 transformed to ADRP/NOP/STR\n", infoC.instructionAddress);
							}
						}
						else {
							// T3 transform already done by ld::passes:got:doPass()
							if ( _options.verboseOptimizationHints() ) {
								fprintf(stderr, "adrp-ldr-got-str at 0x%08llX T3 transformed to ADRP/ADD/STR\n", infoC.instructionAddress);
							}
						}
					}
					else {
						if ( _options.verboseOptimizationHints() ) 							
							fprintf(stderr, "adrp-ldr-got-str at 0x%08llX not ADD or LDR\n", infoC.instructionAddress);
					}
					break;
				case LOH_ARM64_ADRP_LDR_GOT:
					LOH_ASSERT(alt.info.count == 1);
					LOH_ASSERT(isPageKind(infoA.fixup, true));
					LOH_ASSERT(isPageOffsetKind(infoB.fixup, true));
					LOH_ASSERT(infoA.target == infoB.target);
					LOH_ASSERT(infoA.targetAddress == infoB.targetAddress);
					isADRP = parseADRP(infoA.instruction, adrpInfoA);
					isADD = parseADD(infoB.instruction, addInfoB);
					isLDR = parseLoadOrStore(infoB.instruction, ldrInfoB);
					if ( isADRP ) {
						if ( isLDR ) {
							if ( usableSegment && withinOneMeg(infoB.instructionAddress, infoA.targetAddress) ) {
								// can do T5 transform (LDR literal load of GOT)
								set32LE(infoA.instructionContent, makeNOP());
								set32LE(infoB.instructionContent, makeLDR_literal(ldrInfoB, infoA.targetAddress, infoB.instructionAddress));
								if ( _options.verboseOptimizationHints() ) {
									fprintf(stderr, "adrp-ldr-got at 0x%08llX T5 transformed to NOP/LDR\n", infoC.instructionAddress);
								}
							}
						}
						else if ( isADD ) {
							if ( usableSegment && withinOneMeg(infoA.instructionAddress, infoA.targetAddress) ) {
								// can do T4 transform (ADR to compute local address)
								set32LE(infoA.instructionContent, makeADR(addInfoB.destReg, infoA.targetAddress, infoA.instructionAddress));
								set32LE(infoB.instructionContent, makeNOP());
								if ( _options.verboseOptimizationHints() ) {
									fprintf(stderr, "adrp-ldr-got at 0x%08llX T4 transformed to ADR/STR\n", infoC.instructionAddress);
								}
							}
						}
						else {
							if ( _options.verboseOptimizationHints() )
								fprintf(stderr, "adrp-ldr-got at 0x%08llX not LDR or ADD\n", infoB.instructionAddress);
						}
					}
					else {
						if ( _options.verboseOptimizationHints() )
							fprintf(stderr, "adrp-ldr-got at 0x%08llX not ADRP\n", infoA.instructionAddress);
					}
					break;
				default:
						if ( _options.verboseOptimizationHints() ) 							
							fprintf(stderr, "unknown hint kind %d alt.info.kind at 0x%08llX\n", alt.info.kind, infoA.instructionAddress);
					break;
			}
		}
		// apply hints pass 2
		for (ld::Fixup::iterator fit = atom->fixupsBegin(), end=atom->fixupsEnd(); fit != end; ++fit) {
			if ( fit->kind != ld::Fixup::kindLinkerOptimizationHint ) 
				continue;
			InstructionInfo infoA;
			InstructionInfo infoB;
			ld::Fixup::LOH_arm64 alt;
			alt.addend = fit->u.addend;
			setInfo(state, atom, buffer, usedByHints, fit->offsetInAtom, (alt.info.delta1 << 2), &infoA);
			if ( alt.info.count > 0 ) 
				setInfo(state, atom, buffer, usedByHints, fit->offsetInAtom, (alt.info.delta2 << 2), &infoB);

			switch ( alt.info.kind ) {
				case LOH_ARM64_ADRP_ADRP:
					LOH_ASSERT(isPageKind(infoA.fixup));
					LOH_ASSERT(isPageKind(infoB.fixup));
					if ( (infoA.instruction & 0x9F000000) != 0x90000000 ) {
						if ( _options.verboseOptimizationHints() )
							fprintf(stderr, "may-reused-adrp at 0x%08llX no longer an ADRP, now 0x%08X\n", infoA.instructionAddress, infoA.instruction);
						sAdrpNA++;
						break;
					}
					if ( (infoB.instruction & 0x9F000000) != 0x90000000 ) {
						if ( _options.verboseOptimizationHints() )
							fprintf(stderr, "may-reused-adrp at 0x%08llX no longer an ADRP, now 0x%08X\n", infoB.instructionAddress, infoA.instruction);
						sAdrpNA++;
						break;
					}
					if ( (infoA.targetAddress & (-4096)) == (infoB.targetAddress & (-4096)) ) {
						set32LE(infoB.instructionContent, 0xD503201F);
						sAdrpNoped++;
					}
					else {
						sAdrpNotNoped++;
					}
					break;
			}				
		}
	}
#endif // SUPPORT_ARCH_arm64

}

void OutputFile::copyNoOps(uint8_t* from, uint8_t* to, bool thumb)
{
	switch ( _options.architecture() ) {
		case CPU_TYPE_I386:
		case CPU_TYPE_X86_64:
			for (uint8_t* p=from; p < to; ++p)
				*p = 0x90;
			break;
		case CPU_TYPE_ARM:
			if ( thumb ) {
				for (uint8_t* p=from; p < to; p += 2)
					OSWriteLittleInt16((uint16_t*)p, 0, 0x46c0);
			}
			else {
				for (uint8_t* p=from; p < to; p += 4)
					OSWriteLittleInt32((uint32_t*)p, 0, 0xe1a00000);
			}
			break;
		default:
			for (uint8_t* p=from; p < to; ++p)
				*p = 0x00;
			break;
	}
}

bool OutputFile::takesNoDiskSpace(const ld::Section* sect)
{
	switch ( sect->type() ) {
		case ld::Section::typeZeroFill:
		case ld::Section::typeTLVZeroFill:
			return _options.optimizeZeroFill();
		case ld::Section::typePageZero:
		case ld::Section::typeStack:
		case ld::Section::typeAbsoluteSymbols:
		case ld::Section::typeTentativeDefs:
			return true;
		default:
			break;
	}
	return false;
}

bool OutputFile::hasZeroForFileOffset(const ld::Section* sect)
{
	switch ( sect->type() ) {
		case ld::Section::typeZeroFill:
		case ld::Section::typeTLVZeroFill:
			return _options.optimizeZeroFill();
		case ld::Section::typePageZero:
		case ld::Section::typeStack:
		case ld::Section::typeTentativeDefs:
			return true;
		default:
			break;
	}
	return false;
}

void OutputFile::writeAtoms(ld::Internal& state, uint8_t* wholeBuffer)
{
	// have each atom write itself
	uint64_t fileOffsetOfEndOfLastAtom = 0;
	uint64_t mhAddress = 0;
	bool lastAtomUsesNoOps = false;
	for (std::vector<ld::Internal::FinalSection*>::iterator sit = state.sections.begin(); sit != state.sections.end(); ++sit) {
		ld::Internal::FinalSection* sect = *sit;
		if ( sect->type() == ld::Section::typeMachHeader )
			mhAddress = sect->address;
		if ( takesNoDiskSpace(sect) )
			continue;
		const bool sectionUsesNops = (sect->type() == ld::Section::typeCode);
		//fprintf(stderr, "file offset=0x%08llX, section %s\n", sect->fileOffset, sect->sectionName());
		std::vector<const ld::Atom*>& atoms = sect->atoms;
		bool lastAtomWasThumb = false;
		for (std::vector<const ld::Atom*>::iterator ait = atoms.begin(); ait != atoms.end(); ++ait) {
			const ld::Atom* atom = *ait;
			if ( atom->definition() == ld::Atom::definitionProxy )
				continue;
			try {
				uint64_t fileOffset = atom->finalAddress() - sect->address + sect->fileOffset;
				// check for alignment padding between atoms
				if ( (fileOffset != fileOffsetOfEndOfLastAtom) && lastAtomUsesNoOps ) {
					this->copyNoOps(&wholeBuffer[fileOffsetOfEndOfLastAtom], &wholeBuffer[fileOffset], lastAtomWasThumb);
				}
				// copy atom content
				atom->copyRawContent(&wholeBuffer[fileOffset]);
				// apply fix ups
				this->applyFixUps(state, mhAddress, atom, &wholeBuffer[fileOffset]);
				fileOffsetOfEndOfLastAtom = fileOffset+atom->size();
				lastAtomUsesNoOps = sectionUsesNops;
				lastAtomWasThumb = atom->isThumb();
			}
			catch (const char* msg) {
				if ( atom->file() != NULL )
					throwf("%s in '%s' from %s", msg, atom->name(), atom->safeFilePath());
				else
					throwf("%s in '%s'", msg, atom->name());
			}
		}
	}
	
	if ( _options.verboseOptimizationHints() ) {
		//fprintf(stderr, "ADRP optimized away:   %d\n", sAdrpNA);
		//fprintf(stderr, "ADRPs changed to NOPs: %d\n", sAdrpNoped);
		//fprintf(stderr, "ADRPs unchanged:       %d\n", sAdrpNotNoped);
	}

	if ( _options.makeThreadedStartsSection() ) {
		assert(_threadedRebaseBindIndices.empty());

		std::vector<OutputFile::BindingInfo>& bindInfo = _bindingInfo;
		std::vector<OutputFile::RebaseInfo>& rebaseInfo = _rebaseInfo;

		std::vector<int64_t>& threadedRebaseBindIndices = _threadedRebaseBindIndices;
		threadedRebaseBindIndices.reserve(bindInfo.size() + rebaseInfo.size());

		for (int64_t i = 0, e = rebaseInfo.size(); i != e; ++i)
			threadedRebaseBindIndices.push_back(-i);

		for (int64_t i = 0, e = bindInfo.size(); i != e; ++i)
			threadedRebaseBindIndices.push_back(i + 1);

		// Now sort the entries by address.
		std::sort(threadedRebaseBindIndices.begin(), threadedRebaseBindIndices.end(),
				  [&rebaseInfo, &bindInfo](int64_t indexA, int64_t indexB) {
					  if (indexA == indexB)
						  return false;
					  uint64_t addressA = indexA <= 0 ? rebaseInfo[-indexA]._address : bindInfo[indexA - 1]._address;
					  uint64_t addressB = indexB <= 0 ? rebaseInfo[-indexB]._address : bindInfo[indexB - 1]._address;
					  assert(addressA != addressB);
					  return addressA < addressB;
				  });
	}

	// new rebasing/binding scheme requires making another pass at DATA
	// segment and building linked list of rebase locations
	if ( _options.useLinkedListBinding() && !_threadedRebaseBindIndices.empty() ) {
		uint64_t curSegStart = 0;
		uint64_t curSegEnd = 0;
		uint32_t curSegIndex = 0;
		ld::Internal::FinalSection* curSection = NULL;

		const uint64_t deltaBits = 11;
		const uint32_t fixupAlignment = _options.makeThreadedStartsSection() ? 4 : 8;
		const bool allowThreadsToCrossPages = _options.makeThreadedStartsSection();
		std::vector<uint64_t> threadStarts;

		// Find the thread starts section
		ld::Internal::FinalSection* threadStartsSection = nullptr;
		uint64_t threadStartsReservedSpace = 0;
		if ( _options.makeThreadedStartsSection() ) {
			for (ld::Internal::FinalSection* sect : state.sections) {
				if ( sect->type() == ld::Section::typeThreadStarts ) {
					threadStartsSection = sect;
					break;
				}
			}
			assert(threadStartsSection);
			threadStartsReservedSpace = (threadStartsSection->size - 4) / 4;
			threadStarts.reserve(threadStartsReservedSpace);
		}
		
		auto getAddress = [this](int64_t index) {
			if (index <= 0)
				return _rebaseInfo[-index]._address;
			else
				return _bindingInfo[index - 1]._address;
		};

		if ( (_bindingInfo.size() > 1)
			&& ! findSegment(state, getAddress(_threadedRebaseBindIndices.front()),
							 &curSegStart, &curSegEnd, &curSegIndex) )
			throw "binding address outside range of any segment";
		
		auto applyBind = [&](int64_t currentIndex, int64_t nextIndex) {
			uint64_t currentAddress = getAddress(currentIndex);
			uint64_t nextAddress = getAddress(nextIndex);

			// The very first pointer we see must be a new chain
			if ( _options.makeThreadedStartsSection() && curSection == NULL )
				threadStarts.push_back(currentAddress);

			if ( (curSection == NULL)
				|| (currentAddress < curSection->address)
				|| (currentAddress >= curSection->address+curSection->size) ) {
				for (ld::Internal::FinalSection* sect : state.sections) {
					if ( (sect->address <= currentAddress)
						&& (currentAddress < sect->address+sect->size) ) {
						curSection = sect;
						break;
					}
				}
			}

			bool makeChainToNextAddress = true;
			if ( allowThreadsToCrossPages ) {
				// Even if we allow threads to cross pages, we still need to have the same section.
				if ( (nextAddress < curSection->address) || (nextAddress >= curSection->address+curSection->size) )
					makeChainToNextAddress = false;
			} else {
				// If threads can't cross pages then make sure they are on the same page.
				uint64_t currentPageIndex = ( currentAddress - curSegStart) / 4096;
				uint64_t nextPageIndex = ( nextAddress - curSegStart) / 4096;
				if ( currentPageIndex != nextPageIndex )
					makeChainToNextAddress = false;
			}

			uint64_t delta = 0;
			if (makeChainToNextAddress) {
				delta = nextAddress - currentAddress;

				// The value should already be aligned to 4 or 8, so make sure the low bits are zeroes
				assert( (delta & (fixupAlignment - 1)) == 0 );
				delta /= fixupAlignment;
				if ( delta >= (1 << deltaBits) ) {
					// Current and next are both in the same segment, so see if they are
					// on the same page.  If so, patch current to point to next.
					makeChainToNextAddress = false;
				}
			}

			if (!makeChainToNextAddress) {
				delta = 0;
				if (_options.makeThreadedStartsSection())
					threadStarts.push_back(nextAddress);
			}

			uint8_t* lastBindLocation = wholeBuffer + curSection->fileOffset + currentAddress - curSection->address;
			switch ( _options.architecture() ) {
				case CPU_TYPE_X86_64:
				case CPU_TYPE_ARM64:
					uint64_t value = 0;
					if (currentIndex <= 0) {
						// For rebases, bits [0..50] is the mh offset which is already set
						// Bit 62 is a 0 to say this is a rebase
						value = get64LE(lastBindLocation);
#if SUPPORT_ARCH_arm64e
						auto fixupOffset = (uintptr_t)(lastBindLocation - mhAddress);
						auto it = _authenticatedFixupData.find(fixupOffset);
						if (it != _authenticatedFixupData.end()) {
							// For authenticated data, we zeroed out the location
							assert(value == 0);
							const auto &authData = it->second.first;
							uint64_t accumulator = it->second.second;
							assert(accumulator >= mhAddress);
							accumulator -= mhAddress;

							// Make sure the high bits aren't set.  The low 32-bits may
							// be the target value.
							assert((accumulator & 0xFFFFFFFF00000000ULL) == 0);
							accumulator |= ((uint64_t)authData.discriminator) << 32;
							accumulator |= ((uint64_t)authData.hasAddressDiversity) << 48;
							accumulator |= ((uint64_t)authData.key) << 49;
							// Set the high bit as we are authenticated
							accumulator |= 1ULL << 63;

							value = accumulator;
						} else
#endif
						{
							// Regular pointer which needs to fit in 51-bits of value.
							// C++ RTTI uses the top bit, so we'll allow the whole top-byte
							// and the bottom 43-bits with sign-extension to be fit in to 51-bits.
							uint64_t top8Bits = value & 0xFF00000000000000ULL;
							uint64_t bottom43Bits = value & 0x000007FFFFFFFFFFULL;
							// Ensure that the sign-extended bottom 43-bits is equivalent in sign to the gap bits
							assert( ((value & ~0xFF0003FFFFFFFFFF) == 0) || ((value & ~0xFF0003FFFFFFFFFF) == ~0xFF0003FFFFFFFFFF) );
							value = ( top8Bits >> 13 ) | bottom43Bits;
						}
					} else {
						// The ordinal in [0..15]
						// Bit 62 is a 1 to say this is a bind
						value = get64LE(lastBindLocation);
#if SUPPORT_ARCH_arm64e
						auto fixupOffset = (uintptr_t)(lastBindLocation - mhAddress);
						auto it = _authenticatedFixupData.find(fixupOffset);
						if (it != _authenticatedFixupData.end()) {
							// For authenticated data, we zeroed out the location
							assert(value == 0);
							const auto &authData = it->second.first;
							uint64_t accumulator = it->second.second;

							// Make sure the high bits aren't set.  The low 32-bits may
							// be the target value.
							// Note, this doesn't work for binds to a weak def as we actually
							// manage to resolve their address to an address in this binary so
							// its not 0.
							if (_bindingInfo[currentIndex - 1]._libraryOrdinal == BIND_SPECIAL_DYLIB_WEAK_LOOKUP)
								accumulator = 0;
							assert((accumulator & 0xFFFFFFFF00000000ULL) == 0);
							accumulator |= ((uint64_t)authData.discriminator) << 32;
							accumulator |= ((uint64_t)authData.hasAddressDiversity) << 48;
							accumulator |= ((uint64_t)authData.key) << 49;
							// Set the high bit as we are authenticated
							accumulator |= 1ULL << 63;

							value = accumulator;
						} else
#endif
						{
							// Regular pointer
							// The current data is unused as we get a new address from the bind table.
							// So zero it out to avoid the bits interfering with the authentication bits.
							value = 0;
						}
						value &= 0xFFFFFFFFFFFF0000;
						value |= _bindingInfo[currentIndex - 1]._threadedBindOrdinal;
						value |= 1ULL << 62;
					}

					// The delta is bits [51..61]
					value |= ( delta << 51 );
					set64LE(lastBindLocation, value);
					break;
			}
		};

		// Loop over every value and see if it needs to point to its successor.
		// Note that on every iteration, info[i] is already known to be in the current
		// segment.
		for (int64_t i = 0, e = _threadedRebaseBindIndices.size() - 1; i != e; ++i) {
			int64_t currentIndex = _threadedRebaseBindIndices[i];
			int64_t nextIndex = _threadedRebaseBindIndices[i + 1];
			uint64_t nextAddress = getAddress(nextIndex);
			if ( (nextAddress < curSegStart) || ( nextAddress >= curSegEnd) ) {
				// The next pointer is in a new segment.
				// This means current is the end of a chain, and we need to move
				// the segment addresses on to be the next ones.
				if ( ! findSegment(state, nextAddress, &curSegStart, &curSegEnd, &curSegIndex) )
					throw "binding address outside range of any segment";
			}
			
			applyBind(currentIndex, nextIndex);
		}
		
		applyBind(_threadedRebaseBindIndices.back(), _threadedRebaseBindIndices.back());

		if ( _options.makeThreadedStartsSection() ) {
			if ( threadStarts.size() > threadStartsReservedSpace )
				throw "overflow in thread starts section";

			// Now write over this section content with the new array.
			const ld::Atom *threadStartsAtom = nullptr;
			for (const ld::Atom *atom : threadStartsSection->atoms) {
				if ( (atom->contentType() == ld::Atom::typeSectionStart) || (atom->contentType() == ld::Atom::typeSectionEnd) ) {
					assert(atom->size() == 0);
					continue;
				}
				assert(threadStartsAtom == nullptr);
				threadStartsAtom = atom;
			}
			uint64_t threadStartsFileOffset = threadStartsAtom->finalAddress() - threadStartsSection->address + threadStartsSection->fileOffset;
			// Skip the header
			threadStartsFileOffset += sizeof(uint32_t);
			for (uint64_t threadStart : threadStarts) {
				uint64_t offset = threadStart - mhAddress;
				assert(offset < 0x100000000);
				set32LE(&wholeBuffer[threadStartsFileOffset], offset);
				threadStartsFileOffset += sizeof(uint32_t);
			}
		}
	}
}

void OutputFile::computeContentUUID(ld::Internal& state, uint8_t* wholeBuffer)
{
	const bool log = false;
	if ( (_options.outputKind() != Options::kObjectFile) || state.someObjectFileHasDwarf ) {
		uint8_t digest[CC_MD5_DIGEST_LENGTH];
		std::vector<std::pair<uint64_t, uint64_t>> excludeRegions;
		uint64_t bitcodeCmdOffset;
		uint64_t bitcodeCmdEnd;
		uint64_t bitcodeSectOffset;
		uint64_t bitcodePaddingEnd;
		if ( _headersAndLoadCommandAtom->bitcodeBundleCommand(bitcodeCmdOffset, bitcodeCmdEnd,
															  bitcodeSectOffset, bitcodePaddingEnd) ) {
			// Exclude embedded bitcode bundle section which contains timestamps in XAR header
			// Note the timestamp is in the compressed XML header which means it might change the size of
			// bitcode section. The load command which include the size of the section and the padding after
			// the bitcode section should also be excluded in the UUID computation.
			// Bitcode section should appears before LINKEDIT
			// Exclude section cmd
			if ( log ) fprintf(stderr, "bundle cmd start=0x%08llX, bundle cmd end=0x%08llX\n",
							   bitcodeCmdOffset, bitcodeCmdEnd);
			excludeRegions.emplace_back(std::pair<uint64_t, uint64_t>(bitcodeCmdOffset, bitcodeCmdEnd));
			// Exclude section content
			if ( log ) fprintf(stderr, "bundle start=0x%08llX, bundle end=0x%08llX\n",
							   bitcodeSectOffset, bitcodePaddingEnd);
			excludeRegions.emplace_back(std::pair<uint64_t, uint64_t>(bitcodeSectOffset, bitcodePaddingEnd));
		}
		uint32_t	stabsStringsOffsetStart;
		uint32_t	tabsStringsOffsetEnd;
		uint32_t	stabsOffsetStart;
		uint32_t	stabsOffsetEnd;
		if ( _symbolTableAtom->hasStabs(stabsStringsOffsetStart, tabsStringsOffsetEnd, stabsOffsetStart, stabsOffsetEnd) ) {
			// find two areas of file that are stabs info and should not contribute to checksum
			uint64_t stringPoolFileOffset = 0;
			uint64_t symbolTableFileOffset = 0;
			for (std::vector<ld::Internal::FinalSection*>::iterator sit = state.sections.begin(); sit != state.sections.end(); ++sit) {
				ld::Internal::FinalSection* sect = *sit;
				if ( sect->type() == ld::Section::typeLinkEdit ) {
					if ( strcmp(sect->sectionName(), "__string_pool") == 0 )
						stringPoolFileOffset = sect->fileOffset;
					else if ( strcmp(sect->sectionName(), "__symbol_table") == 0 )
						symbolTableFileOffset = sect->fileOffset;
				}
			}
			uint64_t firstStabNlistFileOffset  = symbolTableFileOffset + stabsOffsetStart;
			uint64_t lastStabNlistFileOffset   = symbolTableFileOffset + stabsOffsetEnd;
			uint64_t firstStabStringFileOffset = stringPoolFileOffset  + stabsStringsOffsetStart;
			uint64_t lastStabStringFileOffset  = stringPoolFileOffset  + tabsStringsOffsetEnd;
			if ( log ) fprintf(stderr, "stabNlist offset=0x%08llX, size=0x%08llX\n", firstStabNlistFileOffset, lastStabNlistFileOffset-firstStabNlistFileOffset);
			if ( log ) fprintf(stderr, "stabString offset=0x%08llX, size=0x%08llX\n", firstStabStringFileOffset, lastStabStringFileOffset-firstStabStringFileOffset);
			assert(firstStabNlistFileOffset <= firstStabStringFileOffset);
			excludeRegions.emplace_back(std::pair<uint64_t, uint64_t>(firstStabNlistFileOffset, lastStabNlistFileOffset));
			excludeRegions.emplace_back(std::pair<uint64_t, uint64_t>(firstStabStringFileOffset, lastStabStringFileOffset));
			// exclude LINKEDIT LC_SEGMENT (size field depends on stabs size)
			uint64_t linkeditSegCmdOffset;
			uint64_t linkeditSegCmdSize;
			_headersAndLoadCommandAtom->linkeditCmdInfo(linkeditSegCmdOffset, linkeditSegCmdSize);
			excludeRegions.emplace_back(std::pair<uint64_t, uint64_t>(linkeditSegCmdOffset, linkeditSegCmdOffset+linkeditSegCmdSize));
			if ( log ) fprintf(stderr, "linkedit SegCmdOffset=0x%08llX, size=0x%08llX\n", linkeditSegCmdOffset, linkeditSegCmdSize);
			uint64_t symbolTableCmdOffset;
			uint64_t symbolTableCmdSize;
			_headersAndLoadCommandAtom->symbolTableCmdInfo(symbolTableCmdOffset, symbolTableCmdSize);
			excludeRegions.emplace_back(std::pair<uint64_t, uint64_t>(symbolTableCmdOffset, symbolTableCmdOffset+symbolTableCmdSize));
			if ( log ) fprintf(stderr, "linkedit SegCmdOffset=0x%08llX, size=0x%08llX\n", symbolTableCmdOffset, symbolTableCmdSize);
		}
		if ( !excludeRegions.empty() ) {
			CC_MD5_CTX md5state;
			CC_MD5_Init(&md5state);
			// rdar://problem/19487042 include the output leaf file name in the hash
			const char* lastSlash = strrchr(_options.outputFilePath(), '/');
			if ( lastSlash !=  NULL ) {
				CC_MD5_Update(&md5state, lastSlash, strlen(lastSlash));
			}
			// <rdar://problem/38679559> use train name when calculating a binary's UUID
			const char* buildName = _options.buildContextName();
			if ( buildName != NULL ) {
				CC_MD5_Update(&md5state, buildName, strlen(buildName));
			}
			std::sort(excludeRegions.begin(), excludeRegions.end());
			uint64_t checksumStart = 0;
			for ( auto& region : excludeRegions ) {
				uint64_t regionStart = region.first;
				uint64_t regionEnd = region.second;
				assert(checksumStart <= regionStart && regionStart <= regionEnd && "Region overlapped");
				if ( log ) fprintf(stderr, "checksum 0x%08llX -> 0x%08llX\n", checksumStart, regionStart);
				CC_MD5_Update(&md5state, &wholeBuffer[checksumStart], regionStart - checksumStart);
				checksumStart = regionEnd;
			}
			if ( log ) fprintf(stderr, "checksum 0x%08llX -> 0x%08llX\n", checksumStart, _fileSize);
			CC_MD5_Update(&md5state, &wholeBuffer[checksumStart], _fileSize-checksumStart);
			CC_MD5_Final(digest, &md5state);
			if ( log ) fprintf(stderr, "uuid=%02X, %02X, %02X, %02X, %02X, %02X, %02X, %02X\n", digest[0], digest[1], digest[2],
							   digest[3], digest[4], digest[5], digest[6],  digest[7]);
		}
		else {
			CC_MD5(wholeBuffer, _fileSize, digest);
		}
		// <rdar://problem/6723729> LC_UUID uuids should conform to RFC 4122 UUID version 4 & UUID version 5 formats
		digest[6] = ( digest[6] & 0x0F ) | ( 3 << 4 );
		digest[8] = ( digest[8] & 0x3F ) | 0x80;
		// update buffer with new UUID
		_headersAndLoadCommandAtom->setUUID(digest);
		_headersAndLoadCommandAtom->recopyUUIDCommand();
	}
}

static int sDescriptorOfPathToRemove = -1;
static void removePathAndExit(int sig)
{
	if ( sDescriptorOfPathToRemove != -1 ) {
		char path[MAXPATHLEN];
		if ( ::fcntl(sDescriptorOfPathToRemove, F_GETPATH, path) == 0 )
			::unlink(path);
	}
	fprintf(stderr, "ld: interrupted\n");
	exit(1);
}
	
void OutputFile::writeOutputFile(ld::Internal& state)
{
	// for UNIX conformance, error if file exists and is not writable
	if ( (access(_options.outputFilePath(), F_OK) == 0) && (access(_options.outputFilePath(), W_OK) == -1) )
		throwf("can't write output file: %s", _options.outputFilePath());

	mode_t permissions = 0777;
	if ( _options.outputKind() == Options::kObjectFile )
		permissions = 0666;
	mode_t umask = ::umask(0);
	::umask(umask); // put back the original umask
	permissions &= ~umask;
	// Calling unlink first assures the file is gone so that open creates it with correct permissions
	// It also handles the case where __options.outputFilePath() file is not writable but its directory is
	// And it means we don't have to truncate the file when done writing (in case new is smaller than old)
	// Lastly, only delete existing file if it is a normal file (e.g. not /dev/null).
	struct stat stat_buf;
	bool outputIsRegularFile = false;
	bool outputIsMappableFile = false;
	if ( stat(_options.outputFilePath(), &stat_buf) != -1 ) {
		if (stat_buf.st_mode & S_IFREG) {
			outputIsRegularFile = true;
			// <rdar://problem/12264302> Don't use mmap on non-hfs volumes
			struct statfs fsInfo;
			if ( statfs(_options.outputFilePath(), &fsInfo) != -1 ) {
				if ( (strcmp(fsInfo.f_fstypename, "hfs") == 0) || (strcmp(fsInfo.f_fstypename, "apfs") == 0) ) {
					(void)unlink(_options.outputFilePath());
					outputIsMappableFile = true;
				}
			}
			else {
				outputIsMappableFile = false;
			}
		} 
		else {
			outputIsRegularFile = false;
		}
	}
	else {
		// special files (pipes, devices, etc) must already exist
		outputIsRegularFile = true;
		// output file does not exist yet
		char dirPath[PATH_MAX];
		strcpy(dirPath, _options.outputFilePath());
		char* end = strrchr(dirPath, '/');
		if ( end != NULL ) {
			end[1] = '\0';
			struct statfs fsInfo;
			if ( statfs(dirPath, &fsInfo) != -1 ) {
				if ( (strcmp(fsInfo.f_fstypename, "hfs") == 0) || (strcmp(fsInfo.f_fstypename, "apfs") == 0) ) {
					outputIsMappableFile = true;
				}
			}
		}
	}
	
	//fprintf(stderr, "outputIsMappableFile=%d, outputIsRegularFile=%d, path=%s\n", outputIsMappableFile, outputIsRegularFile, _options.outputFilePath());
	
	int fd;
	// Construct a temporary path of the form {outputFilePath}.ld_XXXXXX
	const char filenameTemplate[] = ".ld_XXXXXX";
	char tmpOutput[PATH_MAX];
	uint8_t *wholeBuffer;
	if ( outputIsRegularFile && outputIsMappableFile ) {
		// <rdar://problem/20959031> ld64 should clean up temporary files on SIGINT
		::signal(SIGINT, removePathAndExit);

		strcpy(tmpOutput, _options.outputFilePath());
		// If the path is too long to add a suffix for a temporary name then
		// just fall back to using the output path. 
		if (strlen(tmpOutput)+strlen(filenameTemplate) < PATH_MAX) {
			strcat(tmpOutput, filenameTemplate);
			fd = mkstemp(tmpOutput);
			sDescriptorOfPathToRemove = fd;
		} 
		else {
			fd = open(tmpOutput, O_RDWR|O_CREAT, permissions);
		}
		if ( fd == -1 ) 
			throwf("can't open output file for writing '%s', errno=%d", tmpOutput, errno);
		if ( ftruncate(fd, _fileSize) == -1 ) {
			int err = errno;
			unlink(tmpOutput);
			if ( err == ENOSPC )
				throwf("not enough disk space for writing '%s'", _options.outputFilePath());
			else
				throwf("can't grow file for writing '%s', errno=%d", _options.outputFilePath(), err);
		}
		
		wholeBuffer = (uint8_t *)mmap(NULL, _fileSize, PROT_WRITE|PROT_READ, MAP_SHARED, fd, 0);
		if ( wholeBuffer == MAP_FAILED )
			throwf("can't create buffer of %llu bytes for output", _fileSize);
	} 
	else {
		if ( outputIsRegularFile )
			fd = open(_options.outputFilePath(),  O_RDWR|O_CREAT, permissions);
		else
			fd = open(_options.outputFilePath(),  O_WRONLY);
		if ( fd == -1 ) 
			throwf("can't open output file for writing: %s, errno=%d", _options.outputFilePath(), errno);
		// try to allocate buffer for entire output file content
		wholeBuffer = (uint8_t*)calloc(_fileSize, 1);
		if ( wholeBuffer == NULL )
			throwf("can't create buffer of %llu bytes for output", _fileSize);
	}
	
	if ( _options.UUIDMode() == Options::kUUIDRandom ) {
		uint8_t bits[16];
		::uuid_generate_random(bits);
		_headersAndLoadCommandAtom->setUUID(bits);
	}

	writeAtoms(state, wholeBuffer);
	
	// compute UUID 
	if ( _options.UUIDMode() == Options::kUUIDContent )
		computeContentUUID(state, wholeBuffer);

	if ( outputIsRegularFile && outputIsMappableFile ) {
		if ( ::chmod(tmpOutput, permissions) == -1 ) {
			unlink(tmpOutput);
			throwf("can't set permissions on output file: %s, errno=%d", tmpOutput, errno);
		}
		if ( ::rename(tmpOutput, _options.outputFilePath()) == -1 && strcmp(tmpOutput, _options.outputFilePath()) != 0) {
			unlink(tmpOutput);
			throwf("can't move output file in place, errno=%d", errno);
		}
	} 
	else {
		if ( ::write(fd, wholeBuffer, _fileSize) == -1 ) {
			throwf("can't write to output file: %s, errno=%d", _options.outputFilePath(), errno);
		}
		sDescriptorOfPathToRemove = -1;
		::close(fd);
		// <rdar://problem/13118223> NFS: iOS incremental builds in Xcode 4.6 fail with codesign error
		// NFS seems to pad the end of the file sometimes.  Calling trunc seems to correct it...
		::truncate(_options.outputFilePath(), _fileSize);
	}

	// Rename symbol map file if needed
	if ( _options.renameReverseSymbolMap() ) {
		assert(_options.hideSymbols() && _options.reverseSymbolMapPath() != NULL && "Must hide symbol and specify a path");
		uuid_string_t UUIDString;
		const uint8_t* rawUUID = _headersAndLoadCommandAtom->getUUID();
		uuid_unparse_upper(rawUUID, UUIDString);
		char outputMapPath[PATH_MAX];
		sprintf(outputMapPath, "%s/%s.bcsymbolmap", _options.reverseSymbolMapPath(), UUIDString);
		if ( ::rename(_options.reverseMapTempPath().c_str(), outputMapPath) != 0 )
			throwf("could not create bcsymbolmap file: %s", outputMapPath);
	}
}

struct AtomByNameSorter
{
	bool operator()(const ld::Atom* left, const ld::Atom* right) const
	{
		return (strcmp(left->name(), right->name()) < 0);
	}

	bool operator()(const ld::Atom* left, const char* right) const
	{
		return (strcmp(left->name(), right) < 0);
	}

	bool operator()(const char* left, const ld::Atom* right) const
	{
		return (strcmp(left, right->name()) < 0);
	}
};


class NotInSet
{
public:
	NotInSet(const std::set<const ld::Atom*>& theSet) : _set(theSet)  {}

	bool operator()(const ld::Atom* atom) const {
		return ( _set.count(atom) == 0 );
	}
private:
	const std::set<const ld::Atom*>&  _set;
};


void OutputFile::buildSymbolTable(ld::Internal& state)
{
	unsigned int machoSectionIndex = 0;
	for (std::vector<ld::Internal::FinalSection*>::iterator sit = state.sections.begin(); sit != state.sections.end(); ++sit) {
		ld::Internal::FinalSection* sect = *sit;
		bool setMachoSectionIndex = !sect->isSectionHidden() && (sect->type() != ld::Section::typeTentativeDefs);
		if ( setMachoSectionIndex ) 
			++machoSectionIndex;
		for (std::vector<const ld::Atom*>::iterator ait = sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
			const ld::Atom* atom = *ait;
			if ( setMachoSectionIndex )
				(const_cast<ld::Atom*>(atom))->setMachoSection(machoSectionIndex);
			else if ( sect->type() == ld::Section::typeMachHeader )
				(const_cast<ld::Atom*>(atom))->setMachoSection(1); // __mh_execute_header is not in any section by needs n_sect==1
			else if ( sect->type() == ld::Section::typeLastSection )
				(const_cast<ld::Atom*>(atom))->setMachoSection(machoSectionIndex); // use section index of previous section
			else if ( sect->type() == ld::Section::typeFirstSection )
				(const_cast<ld::Atom*>(atom))->setMachoSection(machoSectionIndex+1); // use section index of next section
				
			// in -r mode, clarify symbolTableNotInFinalLinkedImages
			if ( _options.outputKind() == Options::kObjectFile ) {
				if ( (_options.architecture() == CPU_TYPE_X86_64)
				  || (_options.architecture() == CPU_TYPE_ARM64)
				   ) {
					// x86_64 .o files need labels on anonymous literal strings
					if ( (sect->type() == ld::Section::typeCString) && (atom->combine() == ld::Atom::combineByNameAndContent) ) {
						(const_cast<ld::Atom*>(atom))->setSymbolTableInclusion(ld::Atom::symbolTableIn);
						_localAtoms.push_back(atom);
						continue;
					}
				}
				if ( sect->type() == ld::Section::typeCFI ) {
					if ( _options.removeEHLabels() )
						(const_cast<ld::Atom*>(atom))->setSymbolTableInclusion(ld::Atom::symbolTableNotIn);
					else
						(const_cast<ld::Atom*>(atom))->setSymbolTableInclusion(ld::Atom::symbolTableIn);
				}
				else if ( sect->type() == ld::Section::typeTempAlias ) {
					assert(_options.outputKind() == Options::kObjectFile);
					_importedAtoms.push_back(atom);
					continue;
				}
				if ( atom->symbolTableInclusion() == ld::Atom::symbolTableNotInFinalLinkedImages )
					(const_cast<ld::Atom*>(atom))->setSymbolTableInclusion(ld::Atom::symbolTableIn);
			}

			// TEMP work around until <rdar://problem/7702923> goes in
			if ( (atom->symbolTableInclusion() == ld::Atom::symbolTableInAndNeverStrip)
				&& (atom->scope() == ld::Atom::scopeLinkageUnit)
				&& (_options.outputKind() == Options::kDynamicLibrary) ) {
					(const_cast<ld::Atom*>(atom))->setScope(ld::Atom::scopeGlobal);
			}
			
			// <rdar://problem/6783167> support auto hidden weak symbols: .weak_def_can_be_hidden
			if ( atom->autoHide() && (_options.outputKind() != Options::kObjectFile) ) {
				// adding auto-hide symbol to .exp file should keep it global
				if ( !_options.hasExportMaskList() || !_options.shouldExport(atom->name()) )
					(const_cast<ld::Atom*>(atom))->setScope(ld::Atom::scopeLinkageUnit);
			}
			
			// <rdar://problem/8626058> ld should consistently warn when resolvers are not exported
			if ( (atom->contentType() == ld::Atom::typeResolver) && (atom->scope() == ld::Atom::scopeLinkageUnit) )
				warning("resolver functions should be external, but '%s' is hidden", atom->name());
			
			if ( sect->type() == ld::Section::typeImportProxies ) {
				if ( atom->combine() == ld::Atom::combineByName )
					this->usesWeakExternalSymbols = true;
				// alias proxy is a re-export with a name change, don't import changed name
				if ( ! atom->isAlias() )
					_importedAtoms.push_back(atom);
				// scope of proxies are usually linkage unit, so done
				// if scope is global, we need to re-export it too
				if ( atom->scope() == ld::Atom::scopeGlobal )
					_exportedAtoms.push_back(atom);
				continue;
			}
			if ( atom->symbolTableInclusion() == ld::Atom::symbolTableNotInFinalLinkedImages ) {
				assert(_options.outputKind() != Options::kObjectFile);
				continue;  // don't add to symbol table
			}
			if ( atom->symbolTableInclusion() == ld::Atom::symbolTableNotIn ) {
				continue;  // don't add to symbol table
			}
			if ( (atom->symbolTableInclusion() == ld::Atom::symbolTableInWithRandomAutoStripLabel) 
				&& (_options.outputKind() != Options::kObjectFile) ) {
				continue;  // don't add to symbol table
			}
			
			if ( (atom->definition() == ld::Atom::definitionTentative) && (_options.outputKind() == Options::kObjectFile) ) {
				if ( _options.makeTentativeDefinitionsReal() ) {
					// -r -d turns tentative defintions into real def
					_exportedAtoms.push_back(atom);
				}
				else {
					// in mach-o object files tentative defintions are stored like undefined symbols
					_importedAtoms.push_back(atom);
				}
				continue;
			}

			switch ( atom->scope() ) {
				case ld::Atom::scopeTranslationUnit:
					if ( _options.keepLocalSymbol(atom->name()) ) {	
						_localAtoms.push_back(atom);
					}
					else {
						if ( _options.outputKind() == Options::kObjectFile ) {
							(const_cast<ld::Atom*>(atom))->setSymbolTableInclusion(ld::Atom::symbolTableInWithRandomAutoStripLabel);
							_localAtoms.push_back(atom);
						}
						else
							(const_cast<ld::Atom*>(atom))->setSymbolTableInclusion(ld::Atom::symbolTableNotIn);
					}	
					break;
				case ld::Atom::scopeGlobal:
					_exportedAtoms.push_back(atom);
					break;
				case ld::Atom::scopeLinkageUnit:
					if ( _options.outputKind() == Options::kObjectFile ) {
						if ( _options.keepPrivateExterns() ) {
							if ( atom->symbolTableInclusion() == ld::Atom::symbolTableInWithRandomAutoStripLabel ) {
								// <rdar://problem/42150005> ld -r should not promote static 'l' labels to hidden
								(const_cast<ld::Atom*>(atom))->setScope(ld::Atom::scopeTranslationUnit);
								_localAtoms.push_back(atom);
							}
							else {
								_exportedAtoms.push_back(atom);
							}
						}
						else if ( _options.keepLocalSymbol(atom->name()) ) {
							_localAtoms.push_back(atom);
						}
						else {
							(const_cast<ld::Atom*>(atom))->setSymbolTableInclusion(ld::Atom::symbolTableInWithRandomAutoStripLabel);
							_localAtoms.push_back(atom);
						}
					}
					else {
						if ( _options.keepLocalSymbol(atom->name()) ) 
							_localAtoms.push_back(atom);
						// <rdar://problem/5804214> ld should never have a symbol in the non-lazy indirect symbol table with index 0
						// this works by making __mh_execute_header be a local symbol which takes symbol index 0
						else if ( (atom->symbolTableInclusion() == ld::Atom::symbolTableInAndNeverStrip) && !_options.makeCompressedDyldInfo() && !_options.makeThreadedStartsSection() )
							_localAtoms.push_back(atom);
						else
							(const_cast<ld::Atom*>(atom))->setSymbolTableInclusion(ld::Atom::symbolTableNotIn);
					}
					break;
			}
		}
	}
	
	// <rdar://problem/6978069> ld adds undefined symbol from .exp file to binary
	if ( (_options.outputKind() == Options::kKextBundle) && _options.hasExportRestrictList() ) {
		// search for referenced undefines
		std::set<const ld::Atom*> referencedProxyAtoms;
		for (std::vector<ld::Internal::FinalSection*>::iterator sit=state.sections.begin(); sit != state.sections.end(); ++sit) {
			ld::Internal::FinalSection* sect = *sit;
			for (std::vector<const ld::Atom*>::iterator ait=sect->atoms.begin();  ait != sect->atoms.end(); ++ait) {
				const ld::Atom* atom = *ait;
				for (ld::Fixup::iterator fit = atom->fixupsBegin(), end=atom->fixupsEnd(); fit != end; ++fit) {
					switch ( fit->binding ) {
						case ld::Fixup::bindingsIndirectlyBound:
							referencedProxyAtoms.insert(state.indirectBindingTable[fit->u.bindingIndex]);
							break;
						case ld::Fixup::bindingDirectlyBound:
							referencedProxyAtoms.insert(fit->u.target);
							break;
						default:
							break;
					}
				}
			}
		}
		// remove any unreferenced _importedAtoms
		_importedAtoms.erase(std::remove_if(_importedAtoms.begin(), _importedAtoms.end(), NotInSet(referencedProxyAtoms)), _importedAtoms.end());			
	}
	
	// sort by name
	std::sort(_exportedAtoms.begin(), _exportedAtoms.end(), AtomByNameSorter());
	std::sort(_importedAtoms.begin(), _importedAtoms.end(), AtomByNameSorter());

	std::map<std::string, std::vector<std::string>> addedSymbols;
	std::map<std::string, std::vector<std::string>> hiddenSymbols;
	for (const auto *atom : _exportedAtoms) {
		// The exported symbols have already been sorted. Early exit the loop
		// once we see a symbol that is lexicographically past the special
		// linker symbol.
		if (atom->name()[0] > '$')
			break;

		std::string name(atom->name());
		if (name.rfind("$ld$add$", 7) == 0) {
			auto pos = name.find_first_of('$', 10);
			if (pos == std::string::npos) {
				warning("bad special linker symbol '%s'", atom->name());
				continue;
			}
			auto &&symbolName = name.substr(pos+1);
			auto it = addedSymbols.emplace(symbolName, std::initializer_list<std::string>{name});
			if (!it.second)
				it.first->second.emplace_back(name);
		} else if (name.rfind("$ld$hide$", 8) == 0) {
			auto pos = name.find_first_of('$', 11);
			if (pos == std::string::npos) {
				warning("bad special linker symbol '%s'", atom->name());
				continue;
			}
			auto &&symbolName = name.substr(pos+1);
			auto it = hiddenSymbols.emplace(symbolName, std::initializer_list<std::string>{name});
			if (!it.second)
				it.first->second.emplace_back(name);
		}
	}

	for (const auto &it : addedSymbols) {
		if (!std::binary_search(_exportedAtoms.begin(), _exportedAtoms.end(), it.first.c_str(), AtomByNameSorter()))
			continue;
		for (const auto &symbol :  it.second)
			warning("linker symbol '%s' adds already existing symbol '%s'", symbol.c_str(), it.first.c_str());
	}

	auto it = hiddenSymbols.begin();
	while (it != hiddenSymbols.end()) {
		if (std::binary_search(_exportedAtoms.begin(), _exportedAtoms.end(), it->first.c_str(), AtomByNameSorter()))
			it = hiddenSymbols.erase(it);
		else
			++it;
	}

	for (const auto &it : hiddenSymbols) {
		for (const auto &symbol :  it.second)
			warning("linker symbol '%s' hides a non-existent symbol '%s'", symbol.c_str(), it.first.c_str());
	}
}

void OutputFile::addPreloadLinkEdit(ld::Internal& state)
{
	switch ( _options.architecture() ) {
#if SUPPORT_ARCH_i386
		case CPU_TYPE_I386:
			if ( _hasLocalRelocations ) {
				_localRelocsAtom = new LocalRelocationsAtom<x86>(_options, state, *this);
				localRelocationsSection = state.addAtom(*_localRelocsAtom);
			}
			if ( _hasExternalRelocations ) {
				_externalRelocsAtom = new ExternalRelocationsAtom<x86>(_options, state, *this);
				externalRelocationsSection = state.addAtom(*_externalRelocsAtom);
			}
			if ( _hasDataInCodeInfo ) {
				_dataInCodeAtom = new DataInCodeAtom<x86_64>(_options, state, *this);
				dataInCodeSection = state.addAtom(*_dataInCodeAtom);
			}
			if ( _hasSymbolTable ) {
				_indirectSymbolTableAtom = new IndirectSymbolTableAtom<x86>(_options, state, *this);
				indirectSymbolTableSection = state.addAtom(*_indirectSymbolTableAtom);
				_symbolTableAtom = new SymbolTableAtom<x86>(_options, state, *this);
				symbolTableSection = state.addAtom(*_symbolTableAtom);
				_stringPoolAtom = new StringPoolAtom(_options, state, *this, 4);
				stringPoolSection = state.addAtom(*_stringPoolAtom);
			}
			break;
#endif
#if SUPPORT_ARCH_x86_64
		case CPU_TYPE_X86_64:
			if ( _hasLocalRelocations ) {
				_localRelocsAtom = new LocalRelocationsAtom<x86_64>(_options, state, *this);
				localRelocationsSection = state.addAtom(*_localRelocsAtom);
			}
			if ( _hasExternalRelocations ) {
				_externalRelocsAtom = new ExternalRelocationsAtom<x86_64>(_options, state, *this);
				externalRelocationsSection = state.addAtom(*_externalRelocsAtom);
			}
			if ( _hasDataInCodeInfo ) {
				_dataInCodeAtom = new DataInCodeAtom<x86_64>(_options, state, *this);
				dataInCodeSection = state.addAtom(*_dataInCodeAtom);
			}
			if ( _hasSymbolTable ) {
				_indirectSymbolTableAtom = new IndirectSymbolTableAtom<x86_64>(_options, state, *this);
				indirectSymbolTableSection = state.addAtom(*_indirectSymbolTableAtom);
				_symbolTableAtom = new SymbolTableAtom<x86_64>(_options, state, *this);
				symbolTableSection = state.addAtom(*_symbolTableAtom);
				_stringPoolAtom = new StringPoolAtom(_options, state, *this, 4);
				stringPoolSection = state.addAtom(*_stringPoolAtom);
			}
			break;
#endif
#if SUPPORT_ARCH_arm_any
		case CPU_TYPE_ARM:
			if ( _hasLocalRelocations ) {
				_localRelocsAtom = new LocalRelocationsAtom<arm>(_options, state, *this);
				localRelocationsSection = state.addAtom(*_localRelocsAtom);
			}
			if ( _hasExternalRelocations ) {
				_externalRelocsAtom = new ExternalRelocationsAtom<arm>(_options, state, *this);
				externalRelocationsSection = state.addAtom(*_externalRelocsAtom);
			}
			if ( _hasDataInCodeInfo ) {
				_dataInCodeAtom = new DataInCodeAtom<x86_64>(_options, state, *this);
				dataInCodeSection = state.addAtom(*_dataInCodeAtom);
			}
			if ( _hasSymbolTable ) {
				_indirectSymbolTableAtom = new IndirectSymbolTableAtom<arm>(_options, state, *this);
				indirectSymbolTableSection = state.addAtom(*_indirectSymbolTableAtom);
				_symbolTableAtom = new SymbolTableAtom<arm>(_options, state, *this);
				symbolTableSection = state.addAtom(*_symbolTableAtom);
				_stringPoolAtom = new StringPoolAtom(_options, state, *this, 4);
				stringPoolSection = state.addAtom(*_stringPoolAtom);
			}
			break;
#endif
#if SUPPORT_ARCH_arm64
		case CPU_TYPE_ARM64:
			if ( _hasLocalRelocations ) {
				_localRelocsAtom = new LocalRelocationsAtom<arm64>(_options, state, *this);
				localRelocationsSection = state.addAtom(*_localRelocsAtom);
			}
			if ( _hasExternalRelocations ) {
				_externalRelocsAtom = new ExternalRelocationsAtom<arm64>(_options, state, *this);
				externalRelocationsSection = state.addAtom(*_externalRelocsAtom);
			}
			if ( _hasDataInCodeInfo ) {
				_dataInCodeAtom = new DataInCodeAtom<x86_64>(_options, state, *this);
				dataInCodeSection = state.addAtom(*_dataInCodeAtom);
			}
			if ( _hasSymbolTable ) {
				_indirectSymbolTableAtom = new IndirectSymbolTableAtom<arm64>(_options, state, *this);
				indirectSymbolTableSection = state.addAtom(*_indirectSymbolTableAtom);
				_symbolTableAtom = new SymbolTableAtom<arm64>(_options, state, *this);
				symbolTableSection = state.addAtom(*_symbolTableAtom);
				_stringPoolAtom = new StringPoolAtom(_options, state, *this, 4);
				stringPoolSection = state.addAtom(*_stringPoolAtom);
			}
			break;
#endif
		default:
			throw "-preload not supported";
	}

}


void OutputFile::addLinkEdit(ld::Internal& state)
{
	// for historical reasons, -preload orders LINKEDIT content differently
	if  ( _options.outputKind() == Options::kPreload ) 
		return addPreloadLinkEdit(state);
	
	switch ( _options.architecture() ) {
#if SUPPORT_ARCH_i386
		case CPU_TYPE_I386:
			if ( _hasSectionRelocations ) {
				_sectionsRelocationsAtom = new SectionRelocationsAtom<x86>(_options, state, *this);
				sectionRelocationsSection = state.addAtom(*_sectionsRelocationsAtom);
			}
			if ( _hasDyldInfo ) {
				_rebasingInfoAtom = new RebaseInfoAtom<x86>(_options, state, *this);
				rebaseSection = state.addAtom(*_rebasingInfoAtom);
				
				_bindingInfoAtom = new BindingInfoAtom<x86>(_options, state, *this);
				bindingSection = state.addAtom(*_bindingInfoAtom);
				
				_weakBindingInfoAtom = new WeakBindingInfoAtom<x86>(_options, state, *this);
				weakBindingSection = state.addAtom(*_weakBindingInfoAtom);
				
				_lazyBindingInfoAtom = new LazyBindingInfoAtom<x86>(_options, state, *this);
				lazyBindingSection = state.addAtom(*_lazyBindingInfoAtom);
				
				_exportInfoAtom = new ExportInfoAtom<x86>(_options, state, *this);
				exportSection = state.addAtom(*_exportInfoAtom);
			}
			if ( _hasLocalRelocations ) {
				_localRelocsAtom = new LocalRelocationsAtom<x86>(_options, state, *this);
				localRelocationsSection = state.addAtom(*_localRelocsAtom);
			}
			if  ( _hasSplitSegInfo ) {
				if ( _options.sharedRegionEncodingV2() )
					_splitSegInfoAtom = new SplitSegInfoV2Atom<x86>(_options, state, *this);
				else
					_splitSegInfoAtom = new SplitSegInfoV1Atom<x86>(_options, state, *this);
				splitSegInfoSection = state.addAtom(*_splitSegInfoAtom);
			}
			if ( _hasFunctionStartsInfo ) {
				_functionStartsAtom = new FunctionStartsAtom<x86>(_options, state, *this);
				functionStartsSection = state.addAtom(*_functionStartsAtom);
			}
			if ( _hasDataInCodeInfo ) {
				_dataInCodeAtom = new DataInCodeAtom<x86>(_options, state, *this);
				dataInCodeSection = state.addAtom(*_dataInCodeAtom);
			}
			if ( _hasOptimizationHints ) {
				_optimizationHintsAtom = new OptimizationHintsAtom<x86>(_options, state, *this);
				optimizationHintsSection = state.addAtom(*_optimizationHintsAtom);
			}
			if ( _hasSymbolTable ) {
				_symbolTableAtom = new SymbolTableAtom<x86>(_options, state, *this);
				symbolTableSection = state.addAtom(*_symbolTableAtom);
			}
			if ( _hasExternalRelocations ) {
				_externalRelocsAtom = new ExternalRelocationsAtom<x86>(_options, state, *this);
				externalRelocationsSection = state.addAtom(*_externalRelocsAtom);
			}
			if ( _hasSymbolTable ) {
				_indirectSymbolTableAtom = new IndirectSymbolTableAtom<x86>(_options, state, *this);
				indirectSymbolTableSection = state.addAtom(*_indirectSymbolTableAtom);
				_stringPoolAtom = new StringPoolAtom(_options, state, *this, 4);
				stringPoolSection = state.addAtom(*_stringPoolAtom);
			}
			break;
#endif
#if SUPPORT_ARCH_x86_64
		case CPU_TYPE_X86_64:
			if ( _hasSectionRelocations ) {
				_sectionsRelocationsAtom = new SectionRelocationsAtom<x86_64>(_options, state, *this);
				sectionRelocationsSection = state.addAtom(*_sectionsRelocationsAtom);
			}
			if ( _hasDyldInfo ) {
				_rebasingInfoAtom = new RebaseInfoAtom<x86_64>(_options, state, *this);
				rebaseSection = state.addAtom(*_rebasingInfoAtom);
				
				_bindingInfoAtom = new BindingInfoAtom<x86_64>(_options, state, *this);
				bindingSection = state.addAtom(*_bindingInfoAtom);
				
				_weakBindingInfoAtom = new WeakBindingInfoAtom<x86_64>(_options, state, *this);
				weakBindingSection = state.addAtom(*_weakBindingInfoAtom);
				
				_lazyBindingInfoAtom = new LazyBindingInfoAtom<x86_64>(_options, state, *this);
				lazyBindingSection = state.addAtom(*_lazyBindingInfoAtom);
				
				_exportInfoAtom = new ExportInfoAtom<x86_64>(_options, state, *this);
				exportSection = state.addAtom(*_exportInfoAtom);
			}
			if ( _hasLocalRelocations ) {
				_localRelocsAtom = new LocalRelocationsAtom<x86_64>(_options, state, *this);
				localRelocationsSection = state.addAtom(*_localRelocsAtom);
			}
			if  ( _hasSplitSegInfo ) {
				if ( _options.sharedRegionEncodingV2() )
					_splitSegInfoAtom = new SplitSegInfoV2Atom<x86_64>(_options, state, *this);
				else
					_splitSegInfoAtom = new SplitSegInfoV1Atom<x86_64>(_options, state, *this);
				splitSegInfoSection = state.addAtom(*_splitSegInfoAtom);
			}
			if ( _hasFunctionStartsInfo ) {
				_functionStartsAtom = new FunctionStartsAtom<x86_64>(_options, state, *this);
				functionStartsSection = state.addAtom(*_functionStartsAtom);
			}
			if ( _hasDataInCodeInfo ) {
				_dataInCodeAtom = new DataInCodeAtom<x86_64>(_options, state, *this);
				dataInCodeSection = state.addAtom(*_dataInCodeAtom);
			}
			if ( _hasOptimizationHints ) {
				_optimizationHintsAtom = new OptimizationHintsAtom<x86_64>(_options, state, *this);
				optimizationHintsSection = state.addAtom(*_optimizationHintsAtom);
			}
			if ( _hasSymbolTable ) {
				_symbolTableAtom = new SymbolTableAtom<x86_64>(_options, state, *this);
				symbolTableSection = state.addAtom(*_symbolTableAtom);
			}
			if ( _hasExternalRelocations ) {
				_externalRelocsAtom = new ExternalRelocationsAtom<x86_64>(_options, state, *this);
				externalRelocationsSection = state.addAtom(*_externalRelocsAtom);
			}
			if ( _hasSymbolTable ) {
				_indirectSymbolTableAtom = new IndirectSymbolTableAtom<x86_64>(_options, state, *this);
				indirectSymbolTableSection = state.addAtom(*_indirectSymbolTableAtom);
				_stringPoolAtom = new StringPoolAtom(_options, state, *this, 8);
				stringPoolSection = state.addAtom(*_stringPoolAtom);
			}
			break;
#endif
#if SUPPORT_ARCH_arm_any
		case CPU_TYPE_ARM:
			if ( _hasSectionRelocations ) {
				_sectionsRelocationsAtom = new SectionRelocationsAtom<arm>(_options, state, *this);
				sectionRelocationsSection = state.addAtom(*_sectionsRelocationsAtom);
			}
			if ( _hasDyldInfo ) {
				_rebasingInfoAtom = new RebaseInfoAtom<arm>(_options, state, *this);
				rebaseSection = state.addAtom(*_rebasingInfoAtom);
				
				_bindingInfoAtom = new BindingInfoAtom<arm>(_options, state, *this);
				bindingSection = state.addAtom(*_bindingInfoAtom);
				
				_weakBindingInfoAtom = new WeakBindingInfoAtom<arm>(_options, state, *this);
				weakBindingSection = state.addAtom(*_weakBindingInfoAtom);
				
				_lazyBindingInfoAtom = new LazyBindingInfoAtom<arm>(_options, state, *this);
				lazyBindingSection = state.addAtom(*_lazyBindingInfoAtom);
				
				_exportInfoAtom = new ExportInfoAtom<arm>(_options, state, *this);
				exportSection = state.addAtom(*_exportInfoAtom);
			}
			if ( _hasLocalRelocations ) {
				_localRelocsAtom = new LocalRelocationsAtom<arm>(_options, state, *this);
				localRelocationsSection = state.addAtom(*_localRelocsAtom);
			}
			if  ( _hasSplitSegInfo ) {
				if ( _options.sharedRegionEncodingV2() )
					_splitSegInfoAtom = new SplitSegInfoV2Atom<arm>(_options, state, *this);
				else
					_splitSegInfoAtom = new SplitSegInfoV1Atom<arm>(_options, state, *this);
				splitSegInfoSection = state.addAtom(*_splitSegInfoAtom);
			}
			if ( _hasFunctionStartsInfo ) {
				_functionStartsAtom = new FunctionStartsAtom<arm>(_options, state, *this);
				functionStartsSection = state.addAtom(*_functionStartsAtom);
			}
			if ( _hasDataInCodeInfo ) {
				_dataInCodeAtom = new DataInCodeAtom<arm>(_options, state, *this);
				dataInCodeSection = state.addAtom(*_dataInCodeAtom);
			}
			if ( _hasOptimizationHints ) {
				_optimizationHintsAtom = new OptimizationHintsAtom<arm>(_options, state, *this);
				optimizationHintsSection = state.addAtom(*_optimizationHintsAtom);
			}
			if ( _hasSymbolTable ) {
				_symbolTableAtom = new SymbolTableAtom<arm>(_options, state, *this);
				symbolTableSection = state.addAtom(*_symbolTableAtom);
			}
			if ( _hasExternalRelocations ) {
				_externalRelocsAtom = new ExternalRelocationsAtom<arm>(_options, state, *this);
				externalRelocationsSection = state.addAtom(*_externalRelocsAtom);
			}
			if ( _hasSymbolTable ) {
				_indirectSymbolTableAtom = new IndirectSymbolTableAtom<arm>(_options, state, *this);
				indirectSymbolTableSection = state.addAtom(*_indirectSymbolTableAtom);
				_stringPoolAtom = new StringPoolAtom(_options, state, *this, 4);
				stringPoolSection = state.addAtom(*_stringPoolAtom);
			}
			break;
#endif
#if SUPPORT_ARCH_arm64
		case CPU_TYPE_ARM64:
			if ( _hasSectionRelocations ) {
				_sectionsRelocationsAtom = new SectionRelocationsAtom<arm64>(_options, state, *this);
				sectionRelocationsSection = state.addAtom(*_sectionsRelocationsAtom);
			}
			if ( _hasDyldInfo ) {
				_rebasingInfoAtom = new RebaseInfoAtom<arm64>(_options, state, *this);
				rebaseSection = state.addAtom(*_rebasingInfoAtom);
				
				_bindingInfoAtom = new BindingInfoAtom<arm64>(_options, state, *this);
				bindingSection = state.addAtom(*_bindingInfoAtom);
				
				_weakBindingInfoAtom = new WeakBindingInfoAtom<arm64>(_options, state, *this);
				weakBindingSection = state.addAtom(*_weakBindingInfoAtom);
				
				_lazyBindingInfoAtom = new LazyBindingInfoAtom<arm64>(_options, state, *this);
				lazyBindingSection = state.addAtom(*_lazyBindingInfoAtom);
				
				_exportInfoAtom = new ExportInfoAtom<arm64>(_options, state, *this);
				exportSection = state.addAtom(*_exportInfoAtom);
			}
			if ( _hasLocalRelocations ) {
				_localRelocsAtom = new LocalRelocationsAtom<arm64>(_options, state, *this);
				localRelocationsSection = state.addAtom(*_localRelocsAtom);
			}
			if  ( _hasSplitSegInfo ) {
				if ( _options.sharedRegionEncodingV2() )
					_splitSegInfoAtom = new SplitSegInfoV2Atom<arm64>(_options, state, *this);
				else
					_splitSegInfoAtom = new SplitSegInfoV1Atom<arm64>(_options, state, *this);
				splitSegInfoSection = state.addAtom(*_splitSegInfoAtom);
			}
			if ( _hasFunctionStartsInfo ) {
				_functionStartsAtom = new FunctionStartsAtom<arm64>(_options, state, *this);
				functionStartsSection = state.addAtom(*_functionStartsAtom);
			}
			if ( _hasDataInCodeInfo ) {
				_dataInCodeAtom = new DataInCodeAtom<arm64>(_options, state, *this);
				dataInCodeSection = state.addAtom(*_dataInCodeAtom);
			}
			if ( _hasOptimizationHints ) {
				_optimizationHintsAtom = new OptimizationHintsAtom<arm64>(_options, state, *this);
				optimizationHintsSection = state.addAtom(*_optimizationHintsAtom);
			}
			if ( _hasSymbolTable ) {
				_symbolTableAtom = new SymbolTableAtom<arm64>(_options, state, *this);
				symbolTableSection = state.addAtom(*_symbolTableAtom);
			}
			if ( _hasExternalRelocations ) {
				_externalRelocsAtom = new ExternalRelocationsAtom<arm64>(_options, state, *this);
				externalRelocationsSection = state.addAtom(*_externalRelocsAtom);
			}
			if ( _hasSymbolTable ) {
				_indirectSymbolTableAtom = new IndirectSymbolTableAtom<arm64>(_options, state, *this);
				indirectSymbolTableSection = state.addAtom(*_indirectSymbolTableAtom);
				_stringPoolAtom = new StringPoolAtom(_options, state, *this, 4);
				stringPoolSection = state.addAtom(*_stringPoolAtom);
			}
			break;
#endif
		default:
			throw "unknown architecture";
	}
}

void OutputFile::addLoadCommands(ld::Internal& state)
{
	switch ( _options.architecture() ) {
#if SUPPORT_ARCH_x86_64
		case CPU_TYPE_X86_64:
			_headersAndLoadCommandAtom = new HeaderAndLoadCommandsAtom<x86_64>(_options, state, *this);
			headerAndLoadCommandsSection = state.addAtom(*_headersAndLoadCommandAtom);
			break;
#endif
#if SUPPORT_ARCH_arm_any
		case CPU_TYPE_ARM:
			_headersAndLoadCommandAtom = new HeaderAndLoadCommandsAtom<arm>(_options, state, *this);
			headerAndLoadCommandsSection = state.addAtom(*_headersAndLoadCommandAtom);
			break;
#endif
#if SUPPORT_ARCH_arm64
		case CPU_TYPE_ARM64:
			_headersAndLoadCommandAtom = new HeaderAndLoadCommandsAtom<arm64>(_options, state, *this);
			headerAndLoadCommandsSection = state.addAtom(*_headersAndLoadCommandAtom);
			break;
#endif
#if SUPPORT_ARCH_i386
		case CPU_TYPE_I386:
			_headersAndLoadCommandAtom = new HeaderAndLoadCommandsAtom<x86>(_options, state, *this);
			headerAndLoadCommandsSection = state.addAtom(*_headersAndLoadCommandAtom);
			break;
#endif
		default:
			throw "unknown architecture";
	}
}

uint32_t OutputFile::dylibCount()
{
	return _dylibsToLoad.size();
}

const ld::dylib::File* OutputFile::dylibByOrdinal(unsigned int ordinal)
{
	assert( ordinal > 0 );
	assert( ordinal <= _dylibsToLoad.size() );
	return _dylibsToLoad[ordinal-1];
}

bool OutputFile::hasOrdinalForInstallPath(const char* path, int* ordinal)
{
	for (std::map<const ld::dylib::File*, int>::const_iterator it = _dylibToOrdinal.begin(); it != _dylibToOrdinal.end(); ++it) {
		const char* installPath = it->first->installPath();
		if ( (installPath != NULL) && (strcmp(path, installPath) == 0) ) {
			*ordinal = it->second;
			return true;
		}
	}
	return false;
}

uint32_t OutputFile::dylibToOrdinal(const ld::dylib::File* dylib)
{
	return _dylibToOrdinal[dylib];
}


void OutputFile::buildDylibOrdinalMapping(ld::Internal& state)
{
	// count non-public re-exported dylibs
	unsigned int nonPublicReExportCount = 0;
	for (std::vector<ld::dylib::File*>::iterator it = state.dylibs.begin(); it != state.dylibs.end(); ++it) {
		ld::dylib::File* aDylib = *it;
		if ( aDylib->willBeReExported() && ! aDylib->hasPublicInstallName() ) 
			++nonPublicReExportCount;
	}
	
	// look at each dylib supplied in state
	bool hasReExports = false;
	bool haveLazyDylibs = false;
	for (std::vector<ld::dylib::File*>::iterator it = state.dylibs.begin(); it != state.dylibs.end(); ++it) {
		ld::dylib::File* aDylib = *it;
		int ordinal;
		if ( aDylib == state.bundleLoader ) {
			_dylibToOrdinal[aDylib] = BIND_SPECIAL_DYLIB_MAIN_EXECUTABLE;
		}
		else if ( this->hasOrdinalForInstallPath(aDylib->installPath(), &ordinal) ) {
			// already have a dylib with that install path, map all uses to that ordinal
			_dylibToOrdinal[aDylib] = ordinal;
		}
		else if ( aDylib->willBeLazyLoadedDylib() ) {
			// all lazy dylib need to be at end of ordinals
			haveLazyDylibs = true;
		}
		else if ( aDylib->willBeReExported() && ! aDylib->hasPublicInstallName() && (nonPublicReExportCount >= 2) ) {
			_dylibsToLoad.push_back(aDylib);
			_dylibToOrdinal[aDylib] = BIND_SPECIAL_DYLIB_SELF;
		}
		else {
			// first time this install path seen, create new ordinal
			_dylibsToLoad.push_back(aDylib);
			_dylibToOrdinal[aDylib] = _dylibsToLoad.size();
		}
		if ( aDylib->explicitlyLinked() && aDylib->willBeReExported() )
			hasReExports = true;
	}
	if ( haveLazyDylibs ) {
		// second pass to determine ordinals for lazy loaded dylibs
		for (std::vector<ld::dylib::File*>::iterator it = state.dylibs.begin(); it != state.dylibs.end(); ++it) {
			ld::dylib::File* aDylib = *it;
			if ( aDylib->willBeLazyLoadedDylib() ) {
				int ordinal;
				if ( this->hasOrdinalForInstallPath(aDylib->installPath(), &ordinal) ) {
					// already have a dylib with that install path, map all uses to that ordinal
					_dylibToOrdinal[aDylib] = ordinal;
				}
				else {
					// first time this install path seen, create new ordinal
					_dylibsToLoad.push_back(aDylib);
					_dylibToOrdinal[aDylib] = _dylibsToLoad.size();
				}
			}
		}
	}
	_noReExportedDylibs = !hasReExports;
	//fprintf(stderr, "dylibs:\n");
	//for (std::map<const ld::dylib::File*, int>::const_iterator it = _dylibToOrdinal.begin(); it != _dylibToOrdinal.end(); ++it) {
	//	fprintf(stderr, " %p ord=%u, install_name=%s\n",it->first, it->second, it->first->installPath());
	//}
}

uint32_t OutputFile::lazyBindingInfoOffsetForLazyPointerAddress(uint64_t lpAddress)
{
	return _lazyPointerAddressToInfoOffset[lpAddress];
}

void OutputFile::setLazyBindingInfoOffset(uint64_t lpAddress, uint32_t lpInfoOffset)
{
	_lazyPointerAddressToInfoOffset[lpAddress] = lpInfoOffset;
}

int OutputFile::compressedOrdinalForAtom(const ld::Atom* target)
{
	// flat namespace images use zero for all ordinals
	if ( _options.nameSpace() != Options::kTwoLevelNameSpace )
		return BIND_SPECIAL_DYLIB_FLAT_LOOKUP;

	// handle -interposable
	if ( target->definition() == ld::Atom::definitionRegular )
		return BIND_SPECIAL_DYLIB_SELF;

	// regular ordinal
	const ld::dylib::File* dylib = dynamic_cast<const ld::dylib::File*>(target->file());
	if ( dylib != NULL ) {
		std::map<const ld::dylib::File*, int>::iterator pos = _dylibToOrdinal.find(dylib);
		if ( pos != _dylibToOrdinal.end() )
			return pos->second;
		assert(0 && "dylib not assigned ordinal");
	}
	
	// handle undefined dynamic_lookup
	if ( _options.undefinedTreatment() == Options::kUndefinedDynamicLookup )
		return BIND_SPECIAL_DYLIB_FLAT_LOOKUP;
	
	// handle -U _foo
	if ( _options.allowedUndefined(target->name()) )
		return BIND_SPECIAL_DYLIB_FLAT_LOOKUP;

	throw "can't find ordinal for imported symbol";
}


bool OutputFile::isPcRelStore(const ld::Fixup* fixup)
{
	return fixup->isPcRelStore(_options.outputKind() == Options::kKextBundle);
}

bool OutputFile::isStore(ld::Fixup::Kind kind)
{
	switch ( kind ) { 
		case ld::Fixup::kindNone:
		case ld::Fixup::kindNoneFollowOn:
		case ld::Fixup::kindNoneGroupSubordinate:
		case ld::Fixup::kindNoneGroupSubordinateFDE:
		case ld::Fixup::kindNoneGroupSubordinateLSDA:
		case ld::Fixup::kindNoneGroupSubordinatePersonality:
		case ld::Fixup::kindSetTargetAddress:
		case ld::Fixup::kindSubtractTargetAddress:
		case ld::Fixup::kindAddAddend:
		case ld::Fixup::kindSubtractAddend:
		case ld::Fixup::kindSetTargetImageOffset:
		case ld::Fixup::kindSetTargetSectionOffset:
#if SUPPORT_ARCH_arm64e
		case ld::Fixup::kindSetAuthData:
#endif
			return false;
		default:
			break;
	}
	return true;
}


bool OutputFile::setsTarget(const ld::Fixup &fixup)
{
	return fixup.setsTarget(_options.outputKind() == Options::kObjectFile);
}

bool OutputFile::isPointerToTarget(ld::Fixup::Kind kind)
{
	switch ( kind ) { 
		case ld::Fixup::kindSetTargetAddress:
		case ld::Fixup::kindStoreTargetAddressLittleEndian32:
		case ld::Fixup::kindStoreTargetAddressLittleEndian64:
#if SUPPORT_ARCH_arm64e
		case ld::Fixup::kindStoreTargetAddressLittleEndianAuth64:
#endif
		case ld::Fixup::kindStoreTargetAddressBigEndian32:
		case ld::Fixup::kindStoreTargetAddressBigEndian64:
		case ld::Fixup::kindLazyTarget:
			return true;
		default:
			break;
	}
	return false;
}
bool OutputFile::isPointerFromTarget(ld::Fixup::Kind kind)
{
	switch ( kind ) { 
		case ld::Fixup::kindSubtractTargetAddress:
			return true;
		default:
			break;
	}
	return false;
}


uint64_t OutputFile::lookBackAddend(ld::Fixup::iterator fit)
{
	uint64_t addend = 0;
	switch ( fit->clusterSize ) {
		case ld::Fixup::k1of1:
		case ld::Fixup::k1of2:
		case ld::Fixup::k2of2:
			break;
		case ld::Fixup::k2of3:
			--fit;
			switch ( fit->kind ) {
				case ld::Fixup::kindAddAddend:
					addend += fit->u.addend;
					break;
				case ld::Fixup::kindSubtractAddend:
					addend -= fit->u.addend;
					break;
				default:
					throw "unexpected fixup kind for binding";
			}
			break;
		case ld::Fixup::k1of3:
			++fit;
			switch ( fit->kind ) {
				case ld::Fixup::kindAddAddend:
					addend += fit->u.addend;
					break;
				case ld::Fixup::kindSubtractAddend:
					addend -= fit->u.addend;
					break;
				default:
					throw "unexpected fixup kind for binding";
			}
			break;
		default:
			throw "unexpected fixup cluster size for binding";
	}
	return addend;
}


void OutputFile::generateLinkEditInfo(ld::Internal& state)
{
	for (std::vector<ld::Internal::FinalSection*>::iterator sit = state.sections.begin(); sit != state.sections.end(); ++sit) {
		ld::Internal::FinalSection* sect = *sit;
		// record end of last __TEXT section encrypted iPhoneOS apps.
		if ( _options.makeEncryptable() && (strcmp(sect->segmentName(), "__TEXT") == 0) && (strcmp(sect->sectionName(), "__oslogstring") != 0) ) {
			_encryptedTEXTendOffset = pageAlign(sect->fileOffset + sect->size);
		}
		bool objc1ClassRefSection = ( (sect->type() == ld::Section::typeCStringPointer) 
									&& (strcmp(sect->sectionName(), "__cls_refs") == 0)
									&& (strcmp(sect->segmentName(), "__OBJC") == 0) );
		for (std::vector<const ld::Atom*>::iterator ait = sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
			const ld::Atom*		atom = *ait;
			
			// Record regular atoms that override a dylib's weak definitions 
			if ( (atom->scope() == ld::Atom::scopeGlobal) && atom->overridesDylibsWeakDef() ) {
				if ( _options.makeCompressedDyldInfo() ) {
					uint8_t wtype = BIND_TYPE_OVERRIDE_OF_WEAKDEF_IN_DYLIB;
					bool nonWeakDef = (atom->combine() == ld::Atom::combineNever);
					// Don't push weak binding info for threaded bind.
					// Instead we use a special ordinal in the regular bind info
					if ( !_options.useLinkedListBinding() )
						_weakBindingInfo.push_back(BindingInfo(wtype, atom->name(), nonWeakDef, atom->finalAddress(), 0));
				}
				this->overridesWeakExternalSymbols = true;
				if ( _options.warnWeakExports()	)
					warning("overrides weak external symbol: %s", atom->name());
			}
			
			ld::Fixup*			fixupWithTarget = NULL;
			ld::Fixup*			fixupWithMinusTarget = NULL;
			ld::Fixup*			fixupWithStore = NULL;
			ld::Fixup*			fixupWithAddend = NULL;
			const ld::Atom*		target = NULL;
			const ld::Atom*		minusTarget = NULL;
			uint64_t			targetAddend = 0;
			uint64_t			minusTargetAddend = 0;
#if SUPPORT_ARCH_arm64e
			ld::Fixup*			fixupWithAuthData = NULL;
#endif
			for (ld::Fixup::iterator fit = atom->fixupsBegin(); fit != atom->fixupsEnd(); ++fit) {
				if ( fit->firstInCluster() ) {
					fixupWithTarget = NULL;
					fixupWithMinusTarget = NULL;
					fixupWithStore = NULL;
					target = NULL;
					minusTarget = NULL;
					targetAddend = 0;
					minusTargetAddend = 0;
				}
				if ( this->setsTarget(*fit) ) {
					switch ( fit->binding ) {
						case ld::Fixup::bindingNone:
						case ld::Fixup::bindingByNameUnbound:
							break;
						case ld::Fixup::bindingByContentBound:
						case ld::Fixup::bindingDirectlyBound:
							fixupWithTarget = fit;
							target = fit->u.target;
							break;
						case ld::Fixup::bindingsIndirectlyBound:
							fixupWithTarget = fit;
							target = state.indirectBindingTable[fit->u.bindingIndex];
							break;
					}
					assert(target != NULL);
				}
				switch ( fit->kind ) {
					case ld::Fixup::kindAddAddend:
						targetAddend = fit->u.addend;
						fixupWithAddend = fit;
						break;
					case ld::Fixup::kindSubtractAddend:
						minusTargetAddend = fit->u.addend;
						fixupWithAddend = fit;
						break;
					case ld::Fixup::kindSubtractTargetAddress:
						switch ( fit->binding ) {
							case ld::Fixup::bindingNone:
							case ld::Fixup::bindingByNameUnbound:
								break;
							case ld::Fixup::bindingByContentBound:
							case ld::Fixup::bindingDirectlyBound:
								fixupWithMinusTarget = fit;
								minusTarget = fit->u.target;
								break;
							case ld::Fixup::bindingsIndirectlyBound:
								fixupWithMinusTarget = fit;
								minusTarget = state.indirectBindingTable[fit->u.bindingIndex];
								break;
						}
						assert(minusTarget != NULL);
						break;
					case ld::Fixup::kindDataInCodeStartData:
					case ld::Fixup::kindDataInCodeStartJT8:
					case ld::Fixup::kindDataInCodeStartJT16:
					case ld::Fixup::kindDataInCodeStartJT32:
					case ld::Fixup::kindDataInCodeStartJTA32:
					case ld::Fixup::kindDataInCodeEnd:
						hasDataInCode = true;
						break;
#if SUPPORT_ARCH_arm64e
					case ld::Fixup::kindSetAuthData:
						fixupWithAuthData = fit;
						break;
#endif
					default:
                        break;    
				}
				if ( fit->isStore() ) {
					fixupWithStore = fit;
				}
				if ( fit->lastInCluster() ) {
					if ( (fixupWithStore != NULL) && (target != NULL) ) {
						if ( _options.outputKind() == Options::kObjectFile ) {
							this->addSectionRelocs(state, sect, atom, fixupWithTarget, fixupWithMinusTarget, fixupWithAddend, fixupWithStore,
#if SUPPORT_ARCH_arm64e
												   fixupWithAuthData,
#endif
													target, minusTarget, targetAddend, minusTargetAddend);
						}
						else {
							if ( _options.makeCompressedDyldInfo() ) {
								this->addDyldInfo(state, sect, atom, fixupWithTarget, fixupWithMinusTarget, fixupWithStore,
												  target, minusTarget, targetAddend, minusTargetAddend);
							} else if ( _options.makeThreadedStartsSection() ) {
								this->addThreadedRebaseInfo(state, sect, atom, fixupWithTarget, fixupWithMinusTarget, fixupWithStore,
															target, minusTarget, targetAddend, minusTargetAddend);
							}
							else { 
								this->addClassicRelocs(state, sect, atom, fixupWithTarget, fixupWithMinusTarget, fixupWithStore,
													target, minusTarget, targetAddend, minusTargetAddend);
							}
						}
					}
					else if ( objc1ClassRefSection && (target != NULL) && (fixupWithStore == NULL) ) {
						// check for class refs to lazy loaded dylibs
						const ld::dylib::File* dylib = dynamic_cast<const ld::dylib::File*>(target->file());
						if ( (dylib != NULL) && dylib->willBeLazyLoadedDylib() )
							throwf("illegal class reference to %s in lazy loaded dylib %s", target->name(), dylib->path());
					}
				}
			}
		}
	}
}


void OutputFile::noteTextReloc(const ld::Atom* atom, const ld::Atom* target) 
{
	if ( (atom->contentType() == ld::Atom::typeStub) || (atom->contentType() == ld::Atom::typeStubHelper) ) {
		// silently let stubs (synthesized by linker) use text relocs
	}
	else if ( _options.allowTextRelocs() ) {
		if ( _options.warnAboutTextRelocs() )
			warning("text reloc in %s to %s", atom->name(), target->name());
	} 
	else if ( _options.positionIndependentExecutable() && (_options.outputKind() == Options::kDynamicExecutable) 
			 && _options.platforms().minOS(ld::version2010Fall)) {
		if ( ! this->pieDisabled ) {
			switch ( _options.architecture()) {
#if SUPPORT_ARCH_arm64
            case CPU_TYPE_ARM64:
#endif
#if SUPPORT_ARCH_arm64
			{
				const char* demangledName = strdup(_options.demangleSymbol(atom->name()));
				throwf("Absolute addressing not allowed in arm64 code but used in '%s' referencing '%s'", demangledName, _options.demangleSymbol(target->name()));
			}
#endif
            default:
				warning("PIE disabled. Absolute addressing (perhaps -mdynamic-no-pic) not allowed in code signed PIE, "
				"but used in %s from %s. " 
				"To fix this warning, don't compile with -mdynamic-no-pic or link with -Wl,-no_pie", 
				atom->name(), atom->safeFilePath());
			}
		}
		this->pieDisabled = true;
	}
	else if ( (target->scope() == ld::Atom::scopeGlobal) && (target->combine() == ld::Atom::combineByName) ) {
		throwf("illegal text-relocoation (direct reference) to (global,weak) %s in %s from %s in %s", target->name(), target->safeFilePath(), atom->name(), atom->safeFilePath());
	}
	else {
		if ( (target->file() != NULL) && (atom->file() != NULL) )
			throwf("illegal text-relocation to '%s' in %s from '%s' in %s", target->name(), target->safeFilePath(), atom->name(), atom->safeFilePath());
        else
            throwf("illegal text reloc in '%s' to '%s'", atom->name(), target->name());
	}
}

void OutputFile::addDyldInfo(ld::Internal& state,  ld::Internal::FinalSection* sect, const ld::Atom* atom,  
								ld::Fixup* fixupWithTarget, ld::Fixup* fixupWithMinusTarget, ld::Fixup* fixupWithStore,
								const ld::Atom* target, const ld::Atom* minusTarget, 
								uint64_t targetAddend, uint64_t minusTargetAddend)
{
	if ( sect->isSectionHidden() )
		return;

	// no need to rebase or bind PCRel stores
	if ( this->isPcRelStore(fixupWithStore) ) {
		// as long as target is in same linkage unit
		if ( (target == NULL) || (target->definition() != ld::Atom::definitionProxy) ) {
			// make sure target is not global and weak
			if ( (target->scope() == ld::Atom::scopeGlobal) && (target->combine() == ld::Atom::combineByName) && (target->definition() == ld::Atom::definitionRegular)) {
				if ( (atom->section().type() == ld::Section::typeCFI)
					|| (atom->section().type() == ld::Section::typeDtraceDOF)
					|| (atom->section().type() == ld::Section::typeUnwindInfo) ) {
					// ok for __eh_frame and __uwind_info to use pointer diffs to global weak symbols
					return;
				}
				// <rdar://problem/13700961> spurious warning when weak function has reference to itself
				if ( fixupWithTarget->binding == ld::Fixup::bindingDirectlyBound ) {
					// ok to ignore pc-rel references within a weak function to itself
					return;
				}
				// Have direct reference to weak-global.  This should be an indrect reference
				const char* demangledName = strdup(_options.demangleSymbol(atom->name()));
				warning("direct access in function '%s' from file '%s' to global weak symbol '%s' from file '%s' means the weak symbol cannot be overridden at runtime. "
						"This was likely caused by different translation units being compiled with different visibility settings.",
						  demangledName, atom->safeFilePath(), _options.demangleSymbol(target->name()), target->safeFilePath());
			}
			return;
		}
	}

	// no need to rebase or bind PIC internal pointer diff
	if ( minusTarget != NULL ) {
		// with pointer diffs, both need to be in same linkage unit
		assert(minusTarget->definition() != ld::Atom::definitionProxy);
		assert(target != NULL);
		assert(target->definition() != ld::Atom::definitionProxy);
		if ( target == minusTarget ) {
			// This is a compile time constant and could have been optimized away by compiler
			return;
		}
		
		// check if target of pointer-diff is global and weak
		if ( (target->scope() == ld::Atom::scopeGlobal) && (target->combine() == ld::Atom::combineByName) && (target->definition() == ld::Atom::definitionRegular) ) {
			if ( (atom->section().type() == ld::Section::typeCFI)
				|| (atom->section().type() == ld::Section::typeDtraceDOF)
				|| (atom->section().type() == ld::Section::typeUnwindInfo) ) {
				// ok for __eh_frame and __uwind_info to use pointer diffs to global weak symbols
				return;
			}
			// Have direct reference to weak-global.  This should be an indrect reference
			const char* demangledName = strdup(_options.demangleSymbol(atom->name()));
			warning("direct access in function '%s' from file '%s' to global weak symbol '%s' from file '%s' means the weak symbol cannot be overridden at runtime. "
					"This was likely caused by different translation units being compiled with different visibility settings.",
					  demangledName, atom->safeFilePath(), _options.demangleSymbol(target->name()), target->safeFilePath());
		}
		return;
	}

	// no need to rebase or bind an atom's references to itself if the output is not slidable
	if ( (atom == target) && !_options.outputSlidable() )
		return;

	// cluster has no target, so needs no rebasing or binding	
	if ( target == NULL )
		return; 

	const uint64_t pointerSize = (_options.architecture() & CPU_ARCH_ABI64) ? 8 : 4;
	bool inReadOnlySeg = ((_options.initialSegProtection(sect->segmentName()) & VM_PROT_WRITE) == 0);
	bool needsRebase = false;
	bool needsBinding = false;
	bool needsLazyBinding = false;
	bool needsWeakBinding = false;

	uint8_t	rebaseType = REBASE_TYPE_POINTER;
	uint8_t type = BIND_TYPE_POINTER;
	const ld::dylib::File* dylib = dynamic_cast<const ld::dylib::File*>(target->file());
    bool weak_import = (fixupWithTarget->weakImport || ((dylib != NULL) && dylib->forcedWeakLinked()));
	uint64_t address =  atom->finalAddress() + fixupWithTarget->offsetInAtom;
	uint64_t addend = targetAddend - minusTargetAddend;

	// special case lazy pointers
	if ( fixupWithTarget->kind == ld::Fixup::kindLazyTarget ) {
		assert(fixupWithTarget->u.target == target);
		assert(addend == 0);
		// lazy dylib lazy pointers do not have any dyld info
		if ( atom->section().type() == ld::Section::typeLazyDylibPointer )
			return;
		// lazy binding to weak definitions are done differently
		// they are directly bound to target, then have a weak bind in case of a collision
		if ( target->combine() == ld::Atom::combineByName ) {
			if ( target->definition() == ld::Atom::definitionProxy ) {
				// weak def exported from another dylib
				// must non-lazy bind to it plus have weak binding info in case of collision
				needsBinding = true;
				needsWeakBinding = true;
			}
			else {
				// weak def in this linkage unit.  
				// just rebase, plus have weak binding info in case of collision
				// this will be done by other cluster on lazy pointer atom
			}
		}
		else if ( target->contentType() == ld::Atom::typeResolver ) {
			// <rdar://problem/8553647> Hidden resolver functions should not have lazy binding info
			// <rdar://problem/12629331> Resolver function run before initializers when overriding the dyld shared cache
			// The lazy pointers used by stubs used when non-lazy binding to a resolver are not normal lazy pointers
			// and should not be in lazy binding info.
			needsLazyBinding = false;
		}
		else {
			// normal case of a pointer to non-weak-def symbol, so can lazily bind
			needsLazyBinding = true;
		}
	}
	else {
		// everything except lazy pointers
		switch ( target->definition() ) {
			case ld::Atom::definitionProxy:
				if ( (dylib != NULL) && dylib->willBeLazyLoadedDylib() )
					throwf("illegal data reference to %s in lazy loaded dylib %s", target->name(), dylib->path());
				if ( target->contentType() == ld::Atom::typeTLV ) {
					if ( sect->type() != ld::Section::typeTLVPointers )
						throwf("illegal data reference in %s to thread local variable %s in dylib %s", 
								atom->name(), target->name(), dylib->path());
				}
				if ( inReadOnlySeg ) 
					type = BIND_TYPE_TEXT_ABSOLUTE32;
				needsBinding = true;
				if ( target->combine() == ld::Atom::combineByName ) 
					needsWeakBinding = true;
				break;
			case ld::Atom::definitionRegular:
			case ld::Atom::definitionTentative:
				// only slideable images need rebasing info
				if ( _options.outputSlidable() ) {
					needsRebase = true;
				}
				// references to internal symbol never need binding
				if ( target->scope() != ld::Atom::scopeGlobal ) 
					break;
				// reference to global weak def needs weak binding
				if ( (target->combine() == ld::Atom::combineByName) && (target->definition() == ld::Atom::definitionRegular) )
					needsWeakBinding = true;
				else if ( _options.outputKind() == Options::kDynamicExecutable ) {
					// in main executables, the only way regular symbols are indirected is if -interposable is used
					if ( _options.interposable(target->name()) ) {
						needsRebase = false;
						needsBinding = true;
					}
				}
				else {
					// for flat-namespace or interposable two-level-namespace
					// all references to exported symbols get indirected
					if ( (_options.nameSpace() != Options::kTwoLevelNameSpace) || _options.interposable(target->name()) ) {
						// <rdar://problem/5254468> no external relocs for flat objc classes
						if ( strncmp(target->name(), ".objc_class_", 12) == 0 )
							break;
						// no rebase info for references to global symbols that will have binding info
						needsRebase = false;
						needsBinding = true;
					}
					else if ( _options.forceCoalesce(target->name()) ) {
						needsWeakBinding = true;
					}
				}
				break;
			case ld::Atom::definitionAbsolute:
				break;
		}
	}
	
	// <rdar://problem/13828711> if target is an import alias, use base of alias
	if ( target->isAlias() && (target->definition() == ld::Atom::definitionProxy) ) {
		for (ld::Fixup::iterator fit = target->fixupsBegin(), end=target->fixupsEnd(); fit != end; ++fit) {
			if ( fit->firstInCluster() ) {
				if ( fit->kind == ld::Fixup::kindNoneFollowOn ) {
					if ( fit->binding == ld::Fixup::bindingDirectlyBound ) {
						//fprintf(stderr, "switching import of %s to import of %s\n", target->name(),  fit->u.target->name());
						target = fit->u.target;
					}
				}
			}
		}
	}

	// Find the ordinal for the bind target
	int compressedOrdinal = 0;
	if ( needsBinding || needsLazyBinding || needsWeakBinding ) {
		compressedOrdinal = this->compressedOrdinalForAtom(target);
	}
	// Linked list binding puts the weak binds in to the regular binds but with a special ordinal.
	if ( needsWeakBinding && _options.useLinkedListBinding() ) {
		assert(!needsLazyBinding);
		needsWeakBinding = false;
		needsBinding = true;
		needsRebase = false;
		compressedOrdinal = BIND_SPECIAL_DYLIB_WEAK_LOOKUP;
	}

	// record dyld info for this cluster
	if ( needsRebase ) {
		if ( inReadOnlySeg ) {
			noteTextReloc(atom, target);
			sect->hasLocalRelocs = true;  // so dyld knows to change permissions on __TEXT segment
			rebaseType = REBASE_TYPE_TEXT_ABSOLUTE32;
		}
		if ( _options.sharedRegionEligible() ) {
			// <rdar://problem/13287063> when range checking, ignore high byte of arm64 addends
			uint64_t checkAddend = addend;
			if ( (_options.architecture() == CPU_TYPE_ARM64)
			   )
				checkAddend &= 0x0FFFFFFFFFFFFFFFULL;
			if ( checkAddend != 0 ) {
				// make sure the addend does not cause the pointer to point outside the target's segment
				// if it does, update_dyld_shared_cache will not be able to put this dylib into the shared cache
				uint64_t targetAddress = target->finalAddress();
				for (std::vector<ld::Internal::FinalSection*>::iterator sit = state.sections.begin(); sit != state.sections.end(); ++sit) {
					ld::Internal::FinalSection* sct = *sit;
					uint64_t sctEnd = (sct->address+sct->size);
					if ( (sct->address <= targetAddress) && (targetAddress < sctEnd) ) {
						if ( (targetAddress+checkAddend) > sctEnd ) {
							warning("data symbol %s from %s has pointer to %s + 0x%08llX. "  
									"That large of an addend may disable %s from being put in the dyld shared cache.", 
									atom->name(), atom->safeFilePath(), target->name(), addend, _options.installPath() );
						}
					}
				}
			}
		}
		if ( ((address & (pointerSize-1)) != 0) && (rebaseType == REBASE_TYPE_POINTER) ) {
			switch ( _options.unalignedPointerTreatment() ) {
				case Options::kUnalignedPointerError:
					throwf("pointer not aligned at address 0x%llX (%s + %lld from %s)",
							address, atom->name(), (address - atom->finalAddress()), atom->safeFilePath());
					break;
				case Options::kUnalignedPointerWarning:
					warning("pointer not aligned at address 0x%llX (%s + %lld from %s)",
							address, atom->name(), (address - atom->finalAddress()), atom->safeFilePath());
					break;
				case Options::kUnalignedPointerIgnore:
					// do nothing
					break;
			}
			_hasUnalignedFixup = true;
		}
		_rebaseInfo.push_back(RebaseInfo(rebaseType, address));
	}

	if ( needsBinding ) {
		if ( inReadOnlySeg ) {
			noteTextReloc(atom, target);
			sect->hasExternalRelocs = true; // so dyld knows to change permissions on __TEXT segment
		}
		if ( ((address & (pointerSize-1)) != 0) && (type == BIND_TYPE_POINTER) ) {
			switch ( _options.unalignedPointerTreatment() ) {
				case Options::kUnalignedPointerError:
					throwf("pointer not aligned at address 0x%llX (%s + %lld from %s)",
							address, atom->name(), (address - atom->finalAddress()), atom->safeFilePath());
					break;
				case Options::kUnalignedPointerWarning:
					warning("pointer not aligned at address 0x%llX (%s + %lld from %s)",
							address, atom->name(), (address - atom->finalAddress()), atom->safeFilePath());
					break;
				case Options::kUnalignedPointerIgnore:
					// do nothing
					break;
			}
			_hasUnalignedFixup = true;
		}
		_bindingInfo.push_back(BindingInfo(type, compressedOrdinal, target->name(), weak_import, address, addend));
	}
	if ( needsLazyBinding ) {
		if ( _options.bindAtLoad() )
			_bindingInfo.push_back(BindingInfo(type, compressedOrdinal, target->name(), weak_import, address, addend));
		else
			_lazyBindingInfo.push_back(BindingInfo(type, compressedOrdinal, target->name(), weak_import, address, addend));
	}
	if ( needsWeakBinding )
		_weakBindingInfo.push_back(BindingInfo(type, 0, target->name(), false, address, addend));
}

void OutputFile::addThreadedRebaseInfo(ld::Internal& state,  ld::Internal::FinalSection* sect, const ld::Atom* atom,
									   ld::Fixup* fixupWithTarget, ld::Fixup* fixupWithMinusTarget, ld::Fixup* fixupWithStore,
									   const ld::Atom* target, const ld::Atom* minusTarget,
									   uint64_t targetAddend, uint64_t minusTargetAddend)
{
	if ( sect->isSectionHidden() )
		return;

	// no need to rebase or bind PCRel stores
	if ( this->isPcRelStore(fixupWithStore) ) {
		// as long as target is in same linkage unit
		if ( (target == NULL) || (target->definition() != ld::Atom::definitionProxy) ) {
			// make sure target is not global and weak
			if ( (target->scope() == ld::Atom::scopeGlobal) && (target->combine() == ld::Atom::combineByName) && (target->definition() == ld::Atom::definitionRegular)) {
				if ( (atom->section().type() == ld::Section::typeCFI)
					|| (atom->section().type() == ld::Section::typeDtraceDOF)
					|| (atom->section().type() == ld::Section::typeUnwindInfo) ) {
					// ok for __eh_frame and __uwind_info to use pointer diffs to global weak symbols
					return;
				}
				// <rdar://problem/13700961> spurious warning when weak function has reference to itself
				if ( fixupWithTarget->binding == ld::Fixup::bindingDirectlyBound ) {
					// ok to ignore pc-rel references within a weak function to itself
					return;
				}
				// Have direct reference to weak-global.  This should be an indrect reference
				const char* demangledName = strdup(_options.demangleSymbol(atom->name()));
				warning("direct access in function '%s' from file '%s' to global weak symbol '%s' from file '%s' means the weak symbol cannot be overridden at runtime. "
						"This was likely caused by different translation units being compiled with different visibility settings.",
						  demangledName, atom->safeFilePath(), _options.demangleSymbol(target->name()), target->safeFilePath());
			}
			return;
		}
	}

	// no need to rebase or bind PIC internal pointer diff
	if ( minusTarget != NULL ) {
		// with pointer diffs, both need to be in same linkage unit
		assert(minusTarget->definition() != ld::Atom::definitionProxy);
		assert(target != NULL);
		assert(target->definition() != ld::Atom::definitionProxy);
		if ( target == minusTarget ) {
			// This is a compile time constant and could have been optimized away by compiler
			return;
		}

		// check if target of pointer-diff is global and weak
		if ( (target->scope() == ld::Atom::scopeGlobal) && (target->combine() == ld::Atom::combineByName) && (target->definition() == ld::Atom::definitionRegular) ) {
			if ( (atom->section().type() == ld::Section::typeCFI)
				|| (atom->section().type() == ld::Section::typeDtraceDOF)
				|| (atom->section().type() == ld::Section::typeUnwindInfo) ) {
				// ok for __eh_frame and __uwind_info to use pointer diffs to global weak symbols
				return;
			}
			// Have direct reference to weak-global.  This should be an indrect reference
			const char* demangledName = strdup(_options.demangleSymbol(atom->name()));
			warning("direct access in function '%s' from file '%s' to global weak symbol '%s' from file '%s' means the weak symbol cannot be overridden at runtime. "
					"This was likely caused by different translation units being compiled with different visibility settings.",
					  demangledName, atom->safeFilePath(), _options.demangleSymbol(target->name()), target->safeFilePath());
		}
		return;
	}

	// no need to rebase or bind an atom's references to itself if the output is not slidable
	if ( (atom == target) && !_options.outputSlidable() )
		return;

	// cluster has no target, so needs no rebasing or binding
	if ( target == NULL )
		return;

	const uint64_t minAlignment = 4;
	bool inReadOnlySeg = ( strcmp(sect->segmentName(), "__TEXT") == 0 );
	bool needsRebase = false;

	uint8_t	rebaseType = REBASE_TYPE_POINTER;
	uint64_t address =  atom->finalAddress() + fixupWithTarget->offsetInAtom;

	// special case lazy pointers
	switch ( target->definition() ) {
		case ld::Atom::definitionProxy:
			break;
		case ld::Atom::definitionRegular:
		case ld::Atom::definitionTentative:
			needsRebase = true;
			break;
		case ld::Atom::definitionAbsolute:
			break;
	}

	// record dyld info for this cluster
	if ( needsRebase ) {
		if ( inReadOnlySeg ) {
			noteTextReloc(atom, target);
			sect->hasLocalRelocs = true;  // so dyld knows to change permissions on __TEXT segment
		}
		if ( ((address & (minAlignment-1)) != 0) ) {
			throwf("pointer not aligned to at least 4-bytes at address 0x%llX (%s + %lld from %s)",
				   address, atom->name(), (address - atom->finalAddress()), atom->safeFilePath());
		}
		_rebaseInfo.push_back(RebaseInfo(rebaseType, address));
	}
}


void OutputFile::addClassicRelocs(ld::Internal& state, ld::Internal::FinalSection* sect, const ld::Atom* atom, 
								ld::Fixup* fixupWithTarget, ld::Fixup* fixupWithMinusTarget, ld::Fixup* fixupWithStore,
								const ld::Atom* target, const ld::Atom* minusTarget, 
								uint64_t targetAddend, uint64_t minusTargetAddend)
{
	if ( sect->isSectionHidden() )
		return;
	
	// non-lazy-pointer section is encoded in indirect symbol table - not using relocations
	if ( sect->type() == ld::Section::typeNonLazyPointer ) {
		// except kexts and static pie which *do* use relocations
		switch (_options.outputKind()) {
			case Options::kKextBundle:
				break;
			case Options::kStaticExecutable:
				if ( _options.positionIndependentExecutable() )
					break;
				// else fall into default case
			default:
				assert(target != NULL);
				assert(fixupWithTarget != NULL);
				return;
		}
	}
	
	// no need to rebase or bind PCRel stores
	if ( this->isPcRelStore(fixupWithStore) ) {
		// as long as target is in same linkage unit
		if ( (target == NULL) || (target->definition() != ld::Atom::definitionProxy) )
			return;
	}

	// no need to rebase or bind PIC internal pointer diff
	if ( minusTarget != NULL ) {
		// with pointer diffs, both need to be in same linkage unit
		assert(minusTarget->definition() != ld::Atom::definitionProxy);
		assert(target != NULL);
		assert(target->definition() != ld::Atom::definitionProxy);
		// check if target of pointer-diff is global and weak
		if ( (target->scope() == ld::Atom::scopeGlobal) && (target->combine() == ld::Atom::combineByName) && (target->definition() == ld::Atom::definitionRegular) ) {
			if ( (atom->section().type() == ld::Section::typeCFI)
				|| (atom->section().type() == ld::Section::typeDtraceDOF)
				|| (atom->section().type() == ld::Section::typeUnwindInfo) ) {
				// ok for __eh_frame and __uwind_info to use pointer diffs to global weak symbols
				return;
			}
			// Have direct reference to weak-global.  This should be an indrect reference
			const char* demangledName = strdup(_options.demangleSymbol(atom->name()));
			warning("direct access in function '%s' from file '%s' to global weak symbol '%s' from file '%s' means the weak symbol cannot be overridden at runtime. "
					"This was likely caused by different translation units being compiled with different visibility settings.",
					  demangledName, atom->safeFilePath(), _options.demangleSymbol(target->name()), target->safeFilePath());
		}
		return;
	}

	// cluster has no target, so needs no rebasing or binding	
	if ( target == NULL )
		return; 

	assert(_localRelocsAtom != NULL);
	uint64_t relocAddress =  atom->finalAddress() + fixupWithTarget->offsetInAtom - _localRelocsAtom->relocBaseAddress(state);

	bool inReadOnlySeg = ( strcmp(sect->segmentName(), "__TEXT") == 0 );
	bool needsLocalReloc = false;
	bool needsExternReloc = false;

	switch ( fixupWithStore->kind ) {
		case ld::Fixup::kindLazyTarget:
			// lazy pointers don't need relocs
			break;
		case ld::Fixup::kindStoreLittleEndian32:
		case ld::Fixup::kindStoreLittleEndian64:
		case ld::Fixup::kindStoreBigEndian32:
		case ld::Fixup::kindStoreBigEndian64:
		case ld::Fixup::kindStoreTargetAddressLittleEndian32:
		case ld::Fixup::kindStoreTargetAddressLittleEndian64:
#if SUPPORT_ARCH_arm64e
		case ld::Fixup::kindStoreTargetAddressLittleEndianAuth64:
#endif
		case ld::Fixup::kindStoreTargetAddressBigEndian32:
		case ld::Fixup::kindStoreTargetAddressBigEndian64:
			// is pointer 
			switch ( target->definition() ) {
				case ld::Atom::definitionProxy:
					needsExternReloc = true;
					break;
				case ld::Atom::definitionRegular:
				case ld::Atom::definitionTentative:
					// only slideable images need local relocs
					if ( _options.outputSlidable() ) 
						needsLocalReloc = true;
					// references to internal symbol never need binding
					if ( target->scope() != ld::Atom::scopeGlobal ) 
						break;
					// reference to global weak def needs weak binding in dynamic images
					if ( (target->combine() == ld::Atom::combineByName) 
						&& (target->definition() == ld::Atom::definitionRegular)
						&& (_options.outputKind() != Options::kStaticExecutable)
						&& (_options.outputKind() != Options::kPreload) 
						&& (atom != target) ) {
						needsExternReloc = true;
					}
					else if ( _options.outputKind() == Options::kDynamicExecutable ) {
						// in main executables, the only way regular symbols are indirected is if -interposable is used
						if ( _options.interposable(target->name()) ) 
							needsExternReloc = true;
					}
					else {
						// for flat-namespace or interposable two-level-namespace
						// all references to exported symbols get indirected
						if ( (_options.nameSpace() != Options::kTwoLevelNameSpace) || _options.interposable(target->name()) ) {
							// <rdar://problem/5254468> no external relocs for flat objc classes
							if ( strncmp(target->name(), ".objc_class_", 12) == 0 )
								break;
							// no rebase info for references to global symbols that will have binding info
							needsExternReloc = true;
						}
					}
					if ( needsExternReloc )
						needsLocalReloc = false;
					break;
				case ld::Atom::definitionAbsolute:
					break;
			}
			if ( needsExternReloc ) {
				if ( inReadOnlySeg )
					noteTextReloc(atom, target);
				const ld::dylib::File* dylib = dynamic_cast<const ld::dylib::File*>(target->file());
				if ( (dylib != NULL) && dylib->willBeLazyLoadedDylib() )
					throwf("illegal data reference to %s in lazy loaded dylib %s", target->name(), dylib->path());
				_externalRelocsAtom->addExternalPointerReloc(relocAddress, target);
				sect->hasExternalRelocs = true;
				fixupWithTarget->contentAddendOnly = true;
			}
			else if ( needsLocalReloc ) {
				assert(target != NULL);
				if ( inReadOnlySeg )
					noteTextReloc(atom, target);
				_localRelocsAtom->addPointerReloc(relocAddress, target->machoSection());
				sect->hasLocalRelocs = true;
			}
			break;
		case ld::Fixup::kindStoreTargetAddressX86BranchPCRel32:
#if SUPPORT_ARCH_arm64
		case ld::Fixup::kindStoreTargetAddressARM64Branch26:
#endif
			if ( _options.outputKind() == Options::kKextBundle ) {
				assert(target != NULL);
				if ( target->definition() == ld::Atom::definitionProxy ) {
					_externalRelocsAtom->addExternalCallSiteReloc(relocAddress, target);
					fixupWithStore->contentAddendOnly = true;
				}
			}
			break;
		
		case ld::Fixup::kindStoreARMLow16:
		case ld::Fixup::kindStoreThumbLow16:
			// no way to encode rebasing of binding for these instructions
			if ( _options.outputSlidable() || (target->definition() == ld::Atom::definitionProxy) )
				throwf("no supported runtime lo16 relocation in %s from %s to %s", atom->name(), atom->safeFilePath(), target->name());
			break;
				
		case ld::Fixup::kindStoreARMHigh16:
		case ld::Fixup::kindStoreThumbHigh16:
			// no way to encode rebasing of binding for these instructions
			if ( _options.outputSlidable() || (target->definition() == ld::Atom::definitionProxy) )
				throwf("no supported runtime hi16 relocation in %s from %s to %s", atom->name(), atom->safeFilePath(), target->name());
			break;

#if SUPPORT_ARCH_arm64e
		case ld::Fixup::kindStoreLittleEndianAuth64:
			if ( _options.outputKind() == Options::kKextBundle ) {
				if ( target->definition() == ld::Atom::definitionProxy ) {
					_externalRelocsAtom->addExternalPointerReloc(relocAddress, target);
					sect->hasExternalRelocs = true;
					fixupWithTarget->contentAddendOnly = true;
				}
				else {
					_localRelocsAtom->addPointerReloc(relocAddress, target->machoSection());
					sect->hasLocalRelocs = true;
				}
			}
			else {
				throwf("authenticated pointer in atom %s from %s to %s is not supported", atom->name(), atom->safeFilePath(), target->name());
			}
			break;
#endif
		default:
			break;
	}
}


bool OutputFile::useExternalSectionReloc(const ld::Atom* atom, const ld::Atom* target, ld::Fixup* fixupWithTarget)
{
	if ( (_options.architecture() == CPU_TYPE_X86_64)
	  || (_options.architecture() == CPU_TYPE_ARM64)
       ) {
		// x86_64 and ARM64 use external relocations for everthing that has a symbol
		return ( target->symbolTableInclusion() != ld::Atom::symbolTableNotIn );
	}
	
	// <rdar://problem/9513487> support arm branch interworking in -r mode 
	if ( (_options.architecture() == CPU_TYPE_ARM) && (_options.outputKind() == Options::kObjectFile) ) {
		if ( atom->isThumb() != target->isThumb() ) {
			switch ( fixupWithTarget->kind ) {
				// have branch that switches mode, then might be 'b' not 'bl'
				// Force external relocation, since no way to do local reloc for 'b'
				case ld::Fixup::kindStoreTargetAddressThumbBranch22 :
				case ld::Fixup::kindStoreTargetAddressARMBranch24:
					return true;
				default:
					break;
			}
		}
	}
	
	if ( (_options.architecture() == CPU_TYPE_I386) && (_options.outputKind() == Options::kObjectFile) ) {
		if ( target->contentType() == ld::Atom::typeTLV ) 
			return true;
	}

	// most architectures use external relocations only for references
	// to a symbol in another translation unit or for references to "weak symbols" or tentative definitions
	assert(target != NULL);
	if ( target->definition() == ld::Atom::definitionProxy )
		return true;
	if ( (target->definition() == ld::Atom::definitionTentative) && ! _options.makeTentativeDefinitionsReal() )
		return true;
	if ( target->scope() != ld::Atom::scopeGlobal )
		return false;
	if ( (target->combine() == ld::Atom::combineByName) && (target->definition() == ld::Atom::definitionRegular) )
		return true;
	return false;
}

bool OutputFile::useSectionRelocAddend(ld::Fixup* fixupWithTarget)
{
#if SUPPORT_ARCH_arm64
	if ( _options.architecture() == CPU_TYPE_ARM64 ) {
		switch ( fixupWithTarget->kind ) {
			case ld::Fixup::kindStoreARM64Branch26:
			case ld::Fixup::kindStoreARM64Page21:
			case ld::Fixup::kindStoreARM64PageOff12:
				return true;
			default:
				return false;
		}
	}
#endif
	return false;
}




void OutputFile::addSectionRelocs(ld::Internal& state, ld::Internal::FinalSection* sect, const ld::Atom* atom, 
								ld::Fixup* fixupWithTarget, ld::Fixup* fixupWithMinusTarget,  
								ld::Fixup* fixupWithAddend, ld::Fixup* fixupWithStore,
#if SUPPORT_ARCH_arm64e
								  ld::Fixup* fixupWithAuthData,
#endif
								const ld::Atom* target, const ld::Atom* minusTarget, 
								uint64_t targetAddend, uint64_t minusTargetAddend)
{
	if ( sect->isSectionHidden() )
		return;
	
	// in -r mode where there will be no labels on __eh_frame section, there is no need for relocations
	if ( (sect->type() == ld::Section::typeCFI) && _options.removeEHLabels() )
		return;
		
	// non-lazy-pointer section is encoded in indirect symbol table - not using relocations
	if ( sect->type() == ld::Section::typeNonLazyPointer ) 
		return;

	// tentative defs don't have any relocations
	if ( sect->type() == ld::Section::typeTentativeDefs ) 
		return;

	assert(target != NULL);
	assert(fixupWithTarget != NULL);
	bool targetUsesExternalReloc = this->useExternalSectionReloc(atom, target, fixupWithTarget);
	bool minusTargetUsesExternalReloc = (minusTarget != NULL) && this->useExternalSectionReloc(atom, minusTarget, fixupWithMinusTarget);
	
	// in x86_64 and arm64 .o files an external reloc means the content contains just the addend
	if ( (_options.architecture() == CPU_TYPE_X86_64)
	  || (_options.architecture() == CPU_TYPE_ARM64)
	   ) {
		if ( targetUsesExternalReloc ) {
			fixupWithTarget->contentAddendOnly = true;
			fixupWithStore->contentAddendOnly = true;
			if ( this->useSectionRelocAddend(fixupWithStore) && (fixupWithAddend != NULL) )
				fixupWithAddend->contentIgnoresAddend = true;
		}
		if ( minusTargetUsesExternalReloc )
			fixupWithMinusTarget->contentAddendOnly = true;
	}
	else {
		// for other archs, content is addend only with (non pc-rel) pointers
		// pc-rel instructions are funny. If the target is _foo+8 and _foo is 
		// external, then the pc-rel instruction *evalutates* to the address 8.
		if ( targetUsesExternalReloc ) {
			// TLV support for i386 acts like RIP relative addressing
			// The addend is the offset from the PICBase to the end of the instruction 
			if ( (_options.architecture() == CPU_TYPE_I386) 
				 && (_options.outputKind() == Options::kObjectFile)
			     && (fixupWithStore->kind == ld::Fixup::kindStoreX86PCRel32TLVLoad) ) {
				fixupWithTarget->contentAddendOnly = true;
				fixupWithStore->contentAddendOnly = true;
			}
			else if ( isPcRelStore(fixupWithStore) ) {
				fixupWithTarget->contentDetlaToAddendOnly = true;
				fixupWithStore->contentDetlaToAddendOnly = true;
			}
			else if ( minusTarget == NULL ){
				fixupWithTarget->contentAddendOnly = true;
				fixupWithStore->contentAddendOnly = true;
			}
		}
	}
	
	if ( fixupWithStore != NULL ) {
		_sectionsRelocationsAtom->addSectionReloc(sect, fixupWithStore->kind, atom, fixupWithStore->offsetInAtom, 
													targetUsesExternalReloc, minusTargetUsesExternalReloc,
#if SUPPORT_ARCH_arm64e
												  fixupWithAuthData,
#endif
													target, targetAddend, minusTarget, minusTargetAddend);
	}

}

void OutputFile::makeSplitSegInfo(ld::Internal& state)
{
	if ( !_options.sharedRegionEligible() )
		return;
		
	for (std::vector<ld::Internal::FinalSection*>::iterator sit = state.sections.begin(); sit != state.sections.end(); ++sit) {
		ld::Internal::FinalSection* sect = *sit;
		if ( sect->isSectionHidden() )
			continue;
		if ( strcmp(sect->segmentName(), "__TEXT") != 0 )
			continue;
		for (std::vector<const ld::Atom*>::iterator ait = sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
			const ld::Atom* atom = *ait;
			const ld::Atom* target = NULL;
			const ld::Atom* fromTarget = NULL;
            uint64_t accumulator = 0;
            bool thumbTarget;
			bool hadSubtract = false;
			for (ld::Fixup::iterator fit = atom->fixupsBegin(), end=atom->fixupsEnd(); fit != end; ++fit) {
				if ( fit->firstInCluster() ) 
					target = NULL;
				if ( this->setsTarget(*fit) ) {
					accumulator = addressOf(state, fit, &target);
					thumbTarget = targetIsThumb(state, fit);
					if ( thumbTarget ) 
						accumulator |= 1;
				}
				switch ( fit->kind ) {
					case ld::Fixup::kindSubtractTargetAddress:
                        accumulator -= addressOf(state, fit, &fromTarget);
						hadSubtract = true;
						break;
                    case ld::Fixup::kindAddAddend:
						accumulator += fit->u.addend;
						break;
                    case ld::Fixup::kindSubtractAddend:
						accumulator -= fit->u.addend;
						break;
					case ld::Fixup::kindStoreBigEndian32:
					case ld::Fixup::kindStoreLittleEndian32:
					case ld::Fixup::kindStoreLittleEndian64:
					case ld::Fixup::kindStoreTargetAddressLittleEndian32:
					case ld::Fixup::kindStoreTargetAddressLittleEndian64:
						// if no subtract, then this is an absolute pointer which means
						// there is also a text reloc which update_dyld_shared_cache will use.
						if ( ! hadSubtract )
							break;
						// fall through
					case ld::Fixup::kindStoreX86PCRel32:
					case ld::Fixup::kindStoreX86PCRel32_1:
					case ld::Fixup::kindStoreX86PCRel32_2:
					case ld::Fixup::kindStoreX86PCRel32_4:
					case ld::Fixup::kindStoreX86PCRel32GOTLoad:
					case ld::Fixup::kindStoreX86PCRel32GOTLoadNowLEA:
					case ld::Fixup::kindStoreX86PCRel32GOT:
					case ld::Fixup::kindStoreX86PCRel32TLVLoad:
					case ld::Fixup::kindStoreX86PCRel32TLVLoadNowLEA:
					case ld::Fixup::kindStoreTargetAddressX86PCRel32:
					case ld::Fixup::kindStoreTargetAddressX86PCRel32GOTLoad:
					case ld::Fixup::kindStoreTargetAddressX86PCRel32GOTLoadNowLEA:
					case ld::Fixup::kindStoreTargetAddressX86PCRel32TLVLoad:
					case ld::Fixup::kindStoreTargetAddressX86PCRel32TLVLoadNowLEA:
                    case ld::Fixup::kindStoreARMLow16:
                    case ld::Fixup::kindStoreThumbLow16: 
#if SUPPORT_ARCH_arm64
					case ld::Fixup::kindStoreARM64Page21:
					case ld::Fixup::kindStoreARM64GOTLoadPage21:
					case ld::Fixup::kindStoreARM64GOTLeaPage21:
					case ld::Fixup::kindStoreARM64TLVPLoadPage21:
					case ld::Fixup::kindStoreARM64TLVPLoadNowLeaPage21:
					case ld::Fixup::kindStoreTargetAddressARM64Page21:
					case ld::Fixup::kindStoreTargetAddressARM64GOTLoadPage21:
					case ld::Fixup::kindStoreTargetAddressARM64GOTLeaPage21:
					case ld::Fixup::kindStoreTargetAddressARM64TLVPLoadPage21:
					case ld::Fixup::kindStoreTargetAddressARM64TLVPLoadNowLeaPage21:
					case ld::Fixup::kindStoreARM64PCRelToGOT:
#endif
						assert(target != NULL);
						if ( strcmp(sect->segmentName(), target->section().segmentName()) != 0 ) {	
							_splitSegInfos.push_back(SplitSegInfoEntry(atom->finalAddress()+fit->offsetInAtom,fit->kind));
						}
						break;
                    case ld::Fixup::kindStoreARMHigh16: 
                    case ld::Fixup::kindStoreThumbHigh16: 
						assert(target != NULL);
						if ( strcmp(sect->segmentName(), target->section().segmentName()) != 0 ) {
                            // hi16 needs to know upper 4-bits of low16 to compute carry
                            uint32_t extra = (accumulator >> 12) & 0xF;
 							_splitSegInfos.push_back(SplitSegInfoEntry(atom->finalAddress()+fit->offsetInAtom,fit->kind, extra));
						}
						break;
					case ld::Fixup::kindSetTargetImageOffset:
						accumulator = addressOf(state, fit, &target);
						assert(target != NULL);
						hadSubtract = true;
						break;
#if SUPPORT_ARCH_arm64e
					case ld::Fixup::kindStoreLittleEndianAuth64:
					case ld::Fixup::kindStoreTargetAddressLittleEndianAuth64:
					case ld::Fixup::kindSetAuthData:
						throw "authenticated pointers are not supported in split seg v1";
						break;
#endif
					default:
						break;
				}
			}
		}
	}
}

void OutputFile::makeSplitSegInfoV2(ld::Internal& state)
{
	static const bool log = false;
	if ( !_options.sharedRegionEligible() )
		return;
	
	for (std::vector<ld::Internal::FinalSection*>::iterator sit = state.sections.begin(); sit != state.sections.end(); ++sit) {
		ld::Internal::FinalSection* sect = *sit;
		if ( sect->isSectionHidden() )
			continue;
		bool codeSection = (sect->type() == ld::Section::typeCode);
		if (log) fprintf(stderr, "sect: %s, address=0x%llX\n", sect->sectionName(), sect->address);
		for (std::vector<const ld::Atom*>::iterator ait = sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
			const ld::Atom* atom = *ait;
			const ld::Atom* target = NULL;
			const ld::Atom* fromTarget = NULL;
			uint32_t picBase = 0;
            uint64_t accumulator = 0;
            bool thumbTarget;
			bool hadSubtract = false;
			uint8_t fromSectionIndex = atom->machoSection();
			uint8_t toSectionIndex;
			uint8_t kind = 0;
			uint64_t fromOffset = 0;
			uint64_t toOffset = 0;
			uint64_t addend = 0;
			for (ld::Fixup::iterator fit = atom->fixupsBegin(), end=atom->fixupsEnd(); fit != end; ++fit) {
				if ( fit->firstInCluster() ) {
					target = NULL;
					hadSubtract = false;
					fromTarget = NULL;
					kind = 0;
					addend = 0;
					toSectionIndex = 255;
					fromOffset = atom->finalAddress() + fit->offsetInAtom - sect->address;
				}
				if ( this->setsTarget(*fit) ) {
					accumulator = addressAndTarget(state, fit, &target);
					thumbTarget = targetIsThumb(state, fit);
					if ( thumbTarget ) 
						accumulator |= 1;
					toOffset = accumulator - state.atomToSection[target]->address;
					if ( target->definition() != ld::Atom::definitionProxy ) {
						if ( target->section().type() == ld::Section::typeMachHeader )
							toSectionIndex = 0;
						else
							toSectionIndex = target->machoSection();
					}
				}
				switch ( fit->kind ) {
					case ld::Fixup::kindSubtractTargetAddress:
                        accumulator -= addressAndTarget(state, fit, &fromTarget);
						hadSubtract = true;
						break;
                    case ld::Fixup::kindAddAddend:
						accumulator += fit->u.addend;
						addend = fit->u.addend;
						break;
                    case ld::Fixup::kindSubtractAddend:
						accumulator -= fit->u.addend;
						picBase = fit->u.addend;
						break;
					case ld::Fixup::kindSetLazyOffset:
						break;
					case ld::Fixup::kindStoreBigEndian32:
					case ld::Fixup::kindStoreLittleEndian32:
					case ld::Fixup::kindStoreTargetAddressLittleEndian32:
						if ( kind != DYLD_CACHE_ADJ_V2_IMAGE_OFF_32 ) {
							if ( hadSubtract )
								kind = DYLD_CACHE_ADJ_V2_DELTA_32;
							else
								kind = DYLD_CACHE_ADJ_V2_POINTER_32;
						}
						break;
					case ld::Fixup::kindStoreLittleEndian64:
					case ld::Fixup::kindStoreTargetAddressLittleEndian64:
						if ( hadSubtract )
							kind = DYLD_CACHE_ADJ_V2_DELTA_64;
						else if ( _options.useLinkedListBinding() && !this->_hasUnalignedFixup )
							kind = DYLD_CACHE_ADJ_V2_THREADED_POINTER_64;
						else
							kind = DYLD_CACHE_ADJ_V2_POINTER_64;
						break;
#if SUPPORT_ARCH_arm64e
					case ld::Fixup::kindStoreLittleEndianAuth64:
					case ld::Fixup::kindStoreTargetAddressLittleEndianAuth64:
						// FIXME: Do we need to handle subtracts on authenticated pointers?
						assert(!hadSubtract);
						kind = DYLD_CACHE_ADJ_V2_THREADED_POINTER_64;
						break;
#endif
					case ld::Fixup::kindStoreX86PCRel32:
					case ld::Fixup::kindStoreX86PCRel32_1:
					case ld::Fixup::kindStoreX86PCRel32_2:
					case ld::Fixup::kindStoreX86PCRel32_4:
					case ld::Fixup::kindStoreX86PCRel32GOTLoad:
					case ld::Fixup::kindStoreX86PCRel32GOTLoadNowLEA:
					case ld::Fixup::kindStoreX86PCRel32GOT:
					case ld::Fixup::kindStoreX86PCRel32TLVLoad:
					case ld::Fixup::kindStoreX86PCRel32TLVLoadNowLEA:
					case ld::Fixup::kindStoreTargetAddressX86PCRel32:
					case ld::Fixup::kindStoreTargetAddressX86PCRel32GOTLoad:
					case ld::Fixup::kindStoreTargetAddressX86PCRel32GOTLoadNowLEA:
					case ld::Fixup::kindStoreTargetAddressX86PCRel32TLVLoad:
					case ld::Fixup::kindStoreTargetAddressX86PCRel32TLVLoadNowLEA:
#if SUPPORT_ARCH_arm64
					case ld::Fixup::kindStoreARM64PCRelToGOT:
#endif
						if ( (fromSectionIndex != toSectionIndex) || !codeSection )
							kind = DYLD_CACHE_ADJ_V2_DELTA_32;
						break;
#if SUPPORT_ARCH_arm64
					case ld::Fixup::kindStoreARM64Page21:
					case ld::Fixup::kindStoreARM64GOTLoadPage21:
					case ld::Fixup::kindStoreARM64GOTLeaPage21:
					case ld::Fixup::kindStoreARM64TLVPLoadPage21:
					case ld::Fixup::kindStoreARM64TLVPLoadNowLeaPage21:
					case ld::Fixup::kindStoreTargetAddressARM64Page21:
					case ld::Fixup::kindStoreTargetAddressARM64GOTLoadPage21:
					case ld::Fixup::kindStoreTargetAddressARM64GOTLeaPage21:
					case ld::Fixup::kindStoreTargetAddressARM64TLVPLoadPage21:
					case ld::Fixup::kindStoreTargetAddressARM64TLVPLoadNowLeaPage21:
						if ( fromSectionIndex != toSectionIndex )
							kind = DYLD_CACHE_ADJ_V2_ARM64_ADRP;
						break;
					case ld::Fixup::kindStoreARM64PageOff12:
					case ld::Fixup::kindStoreARM64GOTLeaPageOff12:
					case ld::Fixup::kindStoreARM64TLVPLoadNowLeaPageOff12:
					case ld::Fixup::kindStoreTargetAddressARM64PageOff12:
					case ld::Fixup::kindStoreTargetAddressARM64GOTLeaPageOff12:
					case ld::Fixup::kindStoreTargetAddressARM64GOTLoadPageOff12:
					case ld::Fixup::kindStoreTargetAddressARM64TLVPLoadPageOff12:
					case ld::Fixup::kindStoreTargetAddressARM64TLVPLoadNowLeaPageOff12:
						if ( fromSectionIndex != toSectionIndex )
							kind = DYLD_CACHE_ADJ_V2_ARM64_OFF12;
						break;
					case ld::Fixup::kindStoreARM64Branch26:
					case ld::Fixup::kindStoreTargetAddressARM64Branch26:
						if ( fromSectionIndex != toSectionIndex )
							kind = DYLD_CACHE_ADJ_V2_ARM64_BR26;
						break;
#endif
                    case ld::Fixup::kindStoreARMHigh16:
                    case ld::Fixup::kindStoreARMLow16:
						if ( (fromSectionIndex != toSectionIndex) && (fromTarget == atom) ) {
							kind = DYLD_CACHE_ADJ_V2_ARM_MOVW_MOVT;
						}
						break;
 					case ld::Fixup::kindStoreARMBranch24:
					case ld::Fixup::kindStoreTargetAddressARMBranch24:
						if ( fromSectionIndex != toSectionIndex )
							kind = DYLD_CACHE_ADJ_V2_ARM_BR24;
						break;
                    case ld::Fixup::kindStoreThumbLow16:
                    case ld::Fixup::kindStoreThumbHigh16:
						if ( (fromSectionIndex != toSectionIndex) && (fromTarget == atom) ) {
							kind = DYLD_CACHE_ADJ_V2_THUMB_MOVW_MOVT;
						}
						break;
					case ld::Fixup::kindStoreThumbBranch22:
					case ld::Fixup::kindStoreTargetAddressThumbBranch22:
						if ( fromSectionIndex != toSectionIndex )
							kind = DYLD_CACHE_ADJ_V2_THUMB_BR22;
						break;
					case ld::Fixup::kindSetTargetImageOffset:
						kind = DYLD_CACHE_ADJ_V2_IMAGE_OFF_32;
						accumulator = addressAndTarget(state, fit, &target);
						assert(target != NULL);
						toSectionIndex = target->machoSection();
						toOffset = accumulator - state.atomToSection[target]->address;
						hadSubtract = true;
						break;
					default:
						break;
				}
				if ( fit->lastInCluster() ) {
					if ( (kind != 0) && (target != NULL) && (target->definition() != ld::Atom::definitionProxy) ) {
						if ( !hadSubtract && addend )
							toOffset += addend;
						assert(toSectionIndex != 255);
						if (log) fprintf(stderr, "from (%d.%s + 0x%llX) to (%d.%s + 0x%llX), kind=%d, atomAddr=0x%llX, sectAddr=0x%llx\n",
										fromSectionIndex, sect->sectionName(), fromOffset, toSectionIndex, state.atomToSection[target]->sectionName(),
										toOffset, kind, atom->finalAddress(), sect->address);
						_splitSegV2Infos.push_back(SplitSegInfoV2Entry(fromSectionIndex, fromOffset, toSectionIndex, toOffset, kind));
					}
				}
			}
		}
	}
}


void OutputFile::writeMapFile(ld::Internal& state)
{
	if ( _options.generatedMapPath() != NULL ) {
		FILE* mapFile = fopen(_options.generatedMapPath(), "w"); 
		if ( mapFile != NULL ) {
			// write output path
			fprintf(mapFile, "# Path: %s\n", _options.outputFilePath());
			// write output architecure
			fprintf(mapFile, "# Arch: %s\n", _options.architectureName());
			// write UUID
			//if ( fUUIDAtom != NULL ) {
			//	const uint8_t* uuid = fUUIDAtom->getUUID();
			//	fprintf(mapFile, "# UUID: %2X %2X %2X %2X %2X %2X %2X %2X %2X %2X %2X %2X %2X %2X %2X %2X \n",
			//		uuid[0], uuid[1], uuid[2],  uuid[3],  uuid[4],  uuid[5],  uuid[6],  uuid[7],
			//		uuid[8], uuid[9], uuid[10], uuid[11], uuid[12], uuid[13], uuid[14], uuid[15]);
			//}
			// write table of object files
			std::map<const ld::File*, ld::File::Ordinal> readerToOrdinal;
			std::map<ld::File::Ordinal, const ld::File*> ordinalToReader;
			std::map<const ld::File*, uint32_t> readerToFileOrdinal;
			for (std::vector<ld::Internal::FinalSection*>::iterator sit = state.sections.begin(); sit != state.sections.end(); ++sit) {
				ld::Internal::FinalSection* sect = *sit;
				if ( sect->isSectionHidden() ) 
					continue;
				for (std::vector<const ld::Atom*>::iterator ait = sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
					const ld::Atom* atom = *ait;
					const ld::File* reader = atom->originalFile();
					if ( reader == NULL )
						continue;
					ld::File::Ordinal readerOrdinal = reader->ordinal();
					std::map<const ld::File*, ld::File::Ordinal>::iterator pos = readerToOrdinal.find(reader);
					if ( pos == readerToOrdinal.end() ) {
						readerToOrdinal[reader] = readerOrdinal;
						ordinalToReader[readerOrdinal] = reader;
					}
				}
			}
			for (const ld::Atom* atom : state.deadAtoms) {
				const ld::File* reader = atom->originalFile();
				if ( reader == NULL )
					continue;
				ld::File::Ordinal readerOrdinal = reader->ordinal();
				std::map<const ld::File*, ld::File::Ordinal>::iterator pos = readerToOrdinal.find(reader);
				if ( pos == readerToOrdinal.end() ) {
					readerToOrdinal[reader] = readerOrdinal;
					ordinalToReader[readerOrdinal] = reader;
				}
			}
			fprintf(mapFile, "# Object files:\n");
			fprintf(mapFile, "[%3u] %s\n", 0, "linker synthesized");
			uint32_t fileIndex = 1;
			for(std::map<ld::File::Ordinal, const ld::File*>::iterator it = ordinalToReader.begin(); it != ordinalToReader.end(); ++it) {
				fprintf(mapFile, "[%3u] %s\n", fileIndex, it->second->path());
				readerToFileOrdinal[it->second] = fileIndex++;
			}
			// write table of sections
			fprintf(mapFile, "# Sections:\n");
			fprintf(mapFile, "# Address\tSize    \tSegment\tSection\n"); 
			for (std::vector<ld::Internal::FinalSection*>::iterator sit = state.sections.begin(); sit != state.sections.end(); ++sit) {
				ld::Internal::FinalSection* sect = *sit;
				if ( sect->isSectionHidden() ) 
					continue;
				fprintf(mapFile, "0x%08llX\t0x%08llX\t%s\t%s\n", sect->address, sect->size, 
							sect->segmentName(), sect->sectionName());
			}
			// write table of symbols
			fprintf(mapFile, "# Symbols:\n");
			fprintf(mapFile, "# Address\tSize    \tFile  Name\n"); 
			for (std::vector<ld::Internal::FinalSection*>::iterator sit = state.sections.begin(); sit != state.sections.end(); ++sit) {
				ld::Internal::FinalSection* sect = *sit;
				if ( sect->isSectionHidden() ) 
					continue;
				//bool isCstring = (sect->type() == ld::Section::typeCString);
				for (std::vector<const ld::Atom*>::iterator ait = sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
					char buffer[4096];
					const ld::Atom* atom = *ait;
					const char* name = atom->name();
					// don't add auto-stripped aliases to .map file
					if ( (atom->size() == 0) && (atom->symbolTableInclusion() == ld::Atom::symbolTableNotInFinalLinkedImages) )
						continue;
					if ( atom->contentType() == ld::Atom::typeCString ) {
						strcpy(buffer, "literal string: ");
						const char* s = (char*)atom->rawContentPointer();
						char* e = &buffer[4094];
						for (char* b = &buffer[strlen(buffer)]; b < e;) {
							char c = *s++;
							if ( c == '\n' ) {
								*b++ = '\\';
								*b++ = 'n';
							}
							else {
								*b++ = c;
							}
							if ( c == '\0' )
								break;
						}
						buffer[4095] = '\0';
						name = buffer;
					}
					else if ( (atom->contentType() == ld::Atom::typeCFI) && (strcmp(name, "FDE") == 0) ) {
						for (ld::Fixup::iterator fit = atom->fixupsBegin(); fit != atom->fixupsEnd(); ++fit) {
							if ( (fit->kind == ld::Fixup::kindSetTargetAddress) && (fit->clusterSize == ld::Fixup::k1of4) ) {
								if ( (fit->binding == ld::Fixup::bindingDirectlyBound)
								 &&  (fit->u.target->section().type() == ld::Section::typeCode) ) {
									strcpy(buffer, "FDE for: ");
									strlcat(buffer, fit->u.target->name(), 4096);
									name = buffer;
								}
							}
						}
					}
					else if ( atom->contentType() == ld::Atom::typeNonLazyPointer ) {
						strcpy(buffer, "non-lazy-pointer");
						for (ld::Fixup::iterator fit = atom->fixupsBegin(); fit != atom->fixupsEnd(); ++fit) {
							if ( fit->binding == ld::Fixup::bindingsIndirectlyBound ) {
								strcpy(buffer, "non-lazy-pointer-to: ");
								strlcat(buffer, state.indirectBindingTable[fit->u.bindingIndex]->name(), 4096);
								break;
							}
							else if ( fit->binding == ld::Fixup::bindingDirectlyBound ) {
								strcpy(buffer, "non-lazy-pointer-to-local: ");
								strlcat(buffer, fit->u.target->name(), 4096);
								break;
							}
						}
						name = buffer;
					}
					fprintf(mapFile, "0x%08llX\t0x%08llX\t[%3u] %s\n", atom->finalAddress(), atom->size(), 
							readerToFileOrdinal[atom->originalFile()], name);
				}
			}
			// preload check is hack until 26613948 is fixed
			if ( _options.deadCodeStrip() && (_options.outputKind() != Options::kPreload) ) {
				fprintf(mapFile, "\n");
				fprintf(mapFile, "# Dead Stripped Symbols:\n");
				fprintf(mapFile, "#        \tSize    \tFile  Name\n");
				for (const ld::Atom* atom : state.deadAtoms) {
					char buffer[4096];
					const char* name = atom->name();
					// don't add auto-stripped aliases to .map file
					if ( (atom->size() == 0) && (atom->symbolTableInclusion() == ld::Atom::symbolTableNotInFinalLinkedImages) )
						continue;
					if ( atom->contentType() == ld::Atom::typeCString ) {
						strcpy(buffer, "literal string: ");
						const char* s = (char*)atom->rawContentPointer();
						char* e = &buffer[4094];
						for (char* b = &buffer[strlen(buffer)]; b < e;) {
							char c = *s++;
							if ( c == '\n' ) {
								*b++ = '\\';
								*b++ = 'n';
							}
							else {
								*b++ = c;
							}
							if ( c == '\0' )
								break;
						}
						buffer[4095] = '\0';
						name = buffer;
					}
					fprintf(mapFile, "<<dead>> \t0x%08llX\t[%3u] %s\n",  atom->size(),
							readerToFileOrdinal[atom->originalFile()], name);
				}
			}
			fclose(mapFile);
		}
		else {
			warning("could not write map file: %s\n", _options.generatedMapPath());
		}
	}
}

static std::string realPathString(const char* path)
{
	char realName[MAXPATHLEN];
	if ( realpath(path, realName) != NULL )
		return realName;
	return path;
}

void OutputFile::writeJSONEntry(ld::Internal& state)
{
	if ( _options.traceEmitJSON() && (_options.UUIDMode() != Options::kUUIDNone) && (_options.traceOutputFile() != NULL) ) {

		// Convert the UUID to a string.
		const uint8_t* uuid = _headersAndLoadCommandAtom->getUUID();
		uuid_string_t uuidString;

		uuid_unparse(uuid, uuidString);
		
		// Enumerate the dylibs.
		std::vector<const ld::dylib::File*> dynamicList;
		std::vector<const ld::dylib::File*> upwardList;
		std::vector<const ld::dylib::File*> reexportList;

		for (const ld::dylib::File* dylib :  _dylibsToLoad) {
			
			if (dylib->willBeUpwardDylib()) {
			
				upwardList.push_back(dylib);
			} else if (dylib->willBeReExported()) {
			 
				reexportList.push_back(dylib);
			} else {
			
				dynamicList.push_back(dylib);
			}
		}
		
		/*
		 * Build the JSON entry.
		 */
		
		std::string	jsonEntry = "{";

		jsonEntry += "\"uuid\":\"" + std::string(uuidString) + "\",";

		// installPath() returns -final_output for non-dylibs
		const char* lastNameSlash = strrchr(_options.installPath(), '/');
		const char* leafName = (lastNameSlash != NULL) ? lastNameSlash+1 : _options.outputFilePath();
		jsonEntry += "\"name\":\"" + std::string(leafName) + "\",";

		jsonEntry += "\"arch\":\"" + std::string(_options.architectureName()) + "\"";

		if (dynamicList.size() > 0) {
			jsonEntry += ",\"dynamic\":[";
			for (const ld::dylib::File* dylib :  dynamicList) {
				jsonEntry += "\"" + realPathString(dylib->path()) + "\"";
				if ((dylib != dynamicList.back())) {
					jsonEntry += ",";
				}
			}
			jsonEntry += "]";
		}
		
		if (upwardList.size() > 0) {
			jsonEntry += ",\"upward-dynamic\":[";
			for (const ld::dylib::File* dylib :  upwardList) {
				jsonEntry += "\"" + realPathString(dylib->path()) + "\"";
				if ((dylib != upwardList.back())) {
					jsonEntry += ",";
				}
			}
			jsonEntry += "]";
		}
		
		if (reexportList.size() > 0) {
			jsonEntry += ",\"re-exports\":[";
			for (const ld::dylib::File* dylib :  reexportList) {
				jsonEntry += "\"" + realPathString(dylib->path()) + "\"";
				if ((dylib != reexportList.back())) {
					jsonEntry += ",";
				}
			}
			jsonEntry += "]";
		}
		
		if (state.archivePaths.size() > 0) {
			jsonEntry += ",\"archives\":[";
			for (const std::string& archivePath : state.archivePaths) {
				jsonEntry += "\"" + realPathString(archivePath.c_str()) + "\"";
				if ((archivePath != state.archivePaths.back())) {
					jsonEntry += ",";
				}
			}
			jsonEntry += "]";
		}

		if (state.bundleLoader != NULL) {
			jsonEntry += ",\"bundle-loader\":";
			jsonEntry += "\"" + realPathString(state.bundleLoader->path()) + "\"";
		}

		jsonEntry += "}\n";
		
		// Write the JSON entry to the trace file.
		_options.writeToTraceFile(jsonEntry.c_str(), jsonEntry.size());
	}
}
	
// used to sort atoms with debug notes
class DebugNoteSorter
{
public:
	bool operator()(const ld::Atom* left, const ld::Atom* right) const
	{
		// first sort by reader
		ld::File::Ordinal leftFileOrdinal  = left->file()->ordinal();
		ld::File::Ordinal rightFileOrdinal = right->file()->ordinal();
		if ( leftFileOrdinal!= rightFileOrdinal)
			return (leftFileOrdinal < rightFileOrdinal);

		// then sort by atom objectAddress
		uint64_t leftAddr  = left->finalAddress();
		uint64_t rightAddr = right->finalAddress();
		return leftAddr < rightAddr;
	}
};


const char* OutputFile::assureFullPath(const char* path)
{
	if ( path[0] == '/' )
		return path;
	char cwdbuff[MAXPATHLEN];
	if ( getcwd(cwdbuff, MAXPATHLEN) != NULL ) {
		char* result;
		asprintf(&result, "%s/%s", cwdbuff, path);
		if ( result != NULL )
			return result;
	}
	return path;
}

static time_t fileModTime(const char* path) {
	struct stat statBuffer;
	if ( stat(path, &statBuffer) == 0 ) {
		return statBuffer.st_mtime;
	}
	return 0;
}


void OutputFile::synthesizeDebugNotes(ld::Internal& state)
{
	// -S means don't synthesize debug map
	if ( _options.debugInfoStripping() == Options::kDebugInfoNone )
		return;
	// make a vector of atoms that come from files compiled with dwarf debug info
	std::vector<const ld::Atom*> atomsNeedingDebugNotes;
	std::set<const ld::Atom*> atomsWithStabs;
	std::set<const ld::relocatable::File*> filesSeenWithStabs;
	atomsNeedingDebugNotes.reserve(1024);
	const ld::relocatable::File* objFile = NULL;
	bool objFileHasDwarf = false;
	bool objFileHasStabs = false;
	for (std::vector<ld::Internal::FinalSection*>::iterator sit = state.sections.begin(); sit != state.sections.end(); ++sit) {
		ld::Internal::FinalSection* sect = *sit;
		for (std::vector<const ld::Atom*>::iterator ait = sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
			const ld::Atom* atom = *ait;
			// no stabs for atoms that would not be in the symbol table
			if ( atom->symbolTableInclusion() == ld::Atom::symbolTableNotIn )
				continue;
			if ( atom->symbolTableInclusion() == ld::Atom::symbolTableNotInFinalLinkedImages )
				continue;
			if ( atom->symbolTableInclusion() == ld::Atom::symbolTableInWithRandomAutoStripLabel )
				continue;
			// no stabs for absolute symbols
			if ( atom->definition() == ld::Atom::definitionAbsolute ) 
				continue;
			// no stabs for .eh atoms
			if ( atom->contentType() == ld::Atom::typeCFI )
				continue;
			// no stabs for string literal atoms
			if ( atom->contentType() == ld::Atom::typeCString )
				continue;
			// no stabs for kernel dtrace probes
			if ( (_options.outputKind() == Options::kStaticExecutable) && (strncmp(atom->name(), "__dtrace_probe$", 15) == 0) )
				continue;
			const ld::File* file = atom->file();
			if ( file != NULL ) {
				if ( file != objFile ) {
					objFileHasDwarf = false;
					objFileHasStabs = false;
					objFile = dynamic_cast<const ld::relocatable::File*>(file);
					if ( objFile != NULL ) {
						switch ( objFile->debugInfo() ) {
							case ld::relocatable::File::kDebugInfoNone:
								break;
							case ld::relocatable::File::kDebugInfoDwarf:
								objFileHasDwarf = true;
								break;
							case ld::relocatable::File::kDebugInfoStabs:
							case ld::relocatable::File::kDebugInfoStabsUUID:
								objFileHasStabs = true;
								break;
						}
					}
				}
				if ( objFileHasDwarf )
					atomsNeedingDebugNotes.push_back(atom);
				if ( objFileHasStabs ) {
					atomsWithStabs.insert(atom);
					if ( objFile != NULL )
						filesSeenWithStabs.insert(objFile);
				}
			}
		}
	}
	
	// sort by file ordinal then atom ordinal
	std::sort(atomsNeedingDebugNotes.begin(), atomsNeedingDebugNotes.end(), DebugNoteSorter());

	// <rdar://problem/17689030> Add -add_ast_path option to linker which add N_AST stab entry to output
	std::set<std::string> seenAstPaths;
	const std::vector<const char*>&	astPaths = _options.astFilePaths();
	for (std::vector<const char*>::const_iterator it=astPaths.begin(); it != astPaths.end(); it++) {
		const char* path = *it;
		if ( seenAstPaths.count(path) != 0 )
			continue;
		seenAstPaths.insert(path);
		//  emit N_AST
		ld::relocatable::File::Stab astStab;
		astStab.atom	= NULL;
		astStab.type	= N_AST;
		astStab.other	= 0;
		astStab.desc	= 0;
		if ( _options.zeroModTimeInDebugMap() )
			astStab.value = 0;
		else
			astStab.value = fileModTime(path);
		astStab.string	= path;
		state.stabs.push_back(astStab);
	}
	
	// synthesize "debug notes" and add them to master stabs vector
	const char* dirPath = NULL;
	const char* filename = NULL;
	bool wroteStartSO = false;
	state.stabs.reserve(atomsNeedingDebugNotes.size()*4);
	std::unordered_set<const char*, CStringHash, CStringEquals>  seenFiles;
	for (std::vector<const ld::Atom*>::iterator it=atomsNeedingDebugNotes.begin(); it != atomsNeedingDebugNotes.end(); it++) {
		const ld::Atom* atom = *it;
		const ld::File* atomFile = atom->file();
		const ld::relocatable::File* atomObjFile = dynamic_cast<const ld::relocatable::File*>(atomFile);
		//fprintf(stderr, "debug note for %s\n", atom->name());
		const char* newPath = atom->translationUnitSource();
		if ( newPath != NULL ) {
			const char* newDirPath;
			const char* newFilename;
			const char* lastSlash = strrchr(newPath, '/');
			if ( lastSlash == NULL ) 
				continue;
			newFilename = lastSlash+1;
			char* temp = strdup(newPath);
			newDirPath = temp;
			// gdb like directory SO's to end in '/', but dwarf DW_AT_comp_dir usually does not have trailing '/'
			temp[lastSlash-newPath+1] = '\0';
			// need SO's whenever the translation unit source file changes
			if ( (filename == NULL) || (strcmp(newFilename,filename) != 0) || (strcmp(newDirPath,dirPath) != 0)) {
				if ( filename != NULL ) {
					// translation unit change, emit ending SO
					ld::relocatable::File::Stab endFileStab;
					endFileStab.atom		= NULL;
					endFileStab.type		= N_SO;
					endFileStab.other		= 1;
					endFileStab.desc		= 0;
					endFileStab.value		= 0;
					endFileStab.string		= "";
					state.stabs.push_back(endFileStab);
				}
				// new translation unit, emit start SO's
				ld::relocatable::File::Stab dirPathStab;
				dirPathStab.atom		= NULL;
				dirPathStab.type		= N_SO;
				dirPathStab.other		= 0;
				dirPathStab.desc		= 0;
				dirPathStab.value		= 0;
				dirPathStab.string		= newDirPath;
				state.stabs.push_back(dirPathStab);
				ld::relocatable::File::Stab fileStab;
				fileStab.atom		= NULL;
				fileStab.type		= N_SO;
				fileStab.other		= 0;
				fileStab.desc		= 0;
				fileStab.value		= 0;
				fileStab.string		= newFilename;
				state.stabs.push_back(fileStab);
				// Synthesize OSO for start of file
				ld::relocatable::File::Stab objStab;
				objStab.atom		= NULL;
				objStab.type		= N_OSO;
				// <rdar://problem/6337329> linker should put cpusubtype in n_sect field of nlist entry for N_OSO debug note entries
				objStab.other		= atomFile->cpuSubType(); 
				objStab.desc		= 1;
				if ( atomObjFile != NULL ) {
					objStab.string	= assureFullPath(atomObjFile->debugInfoPath());
					if ( _options.zeroModTimeInDebugMap() )
						objStab.value	= 0;
					else
						objStab.value	= atomObjFile->debugInfoModificationTime();
				}
				else {
					objStab.string	= assureFullPath(atomFile->path());
					if ( _options.zeroModTimeInDebugMap() )
						objStab.value	= 0;
					else
						objStab.value	= atomFile->modificationTime();
				}
				state.stabs.push_back(objStab);
				wroteStartSO = true;
				// add the source file path to seenFiles so it does not show up in SOLs
				seenFiles.insert(newFilename);
				char* fullFilePath;
				asprintf(&fullFilePath, "%s%s", newDirPath, newFilename);
				// add both leaf path and full path
				seenFiles.insert(fullFilePath);

				// <rdar://problem/34121435> Add linker support for propagating N_AST debug notes from .o files to linked image
				if ( const std::vector<relocatable::File::AstTimeAndPath>* asts = atomObjFile->astFiles() ) {
					for (const relocatable::File::AstTimeAndPath& file : *asts) {
						const char* cpath = file.path.c_str();
						if ( seenAstPaths.count(cpath) != 0 )
							continue;
						seenAstPaths.insert(cpath);
						//  generate N_AST in output
						ld::relocatable::File::Stab astStab;
						astStab.atom	= NULL;
						astStab.type	= N_AST;
						astStab.other	= 0;
						astStab.desc	= 0;
						astStab.value   = file.time;
						astStab.string	= cpath;
						state.stabs.push_back(astStab);
					}
				}
			}
			filename = newFilename;
			dirPath = newDirPath;
			if ( atom->section().type() == ld::Section::typeCode ) {
				// Synthesize BNSYM and start FUN stabs
				ld::relocatable::File::Stab beginSym;
				beginSym.atom		= atom;
				beginSym.type		= N_BNSYM;
				beginSym.other		= 1;
				beginSym.desc		= 0;
				beginSym.value		= 0;
				beginSym.string		= "";
				state.stabs.push_back(beginSym);
				ld::relocatable::File::Stab startFun;
				startFun.atom		= atom;
				startFun.type		= N_FUN;
				startFun.other		= 1;
				startFun.desc		= 0;
				startFun.value		= 0;
				startFun.string		= atom->name();
				state.stabs.push_back(startFun);
				// Synthesize any SOL stabs needed
				const char* curFile = NULL;
				for (ld::Atom::LineInfo::iterator lit = atom->beginLineInfo(); lit != atom->endLineInfo(); ++lit) {
					if ( lit->fileName != curFile ) {
						if ( seenFiles.count(lit->fileName) == 0 ) {
							seenFiles.insert(lit->fileName);
							ld::relocatable::File::Stab sol;
							sol.atom		= 0;
							sol.type		= N_SOL;
							sol.other		= 0;
							sol.desc		= 0;
							sol.value		= 0;
							sol.string		= lit->fileName;
							state.stabs.push_back(sol);
						}
						curFile = lit->fileName;
					}
				}
				// Synthesize end FUN and ENSYM stabs
				ld::relocatable::File::Stab endFun;
				endFun.atom			= atom;
				endFun.type			= N_FUN;
				endFun.other		= 0;
				endFun.desc			= 0;
				endFun.value		= 0;
				endFun.string		= "";
				state.stabs.push_back(endFun);
				ld::relocatable::File::Stab endSym;
				endSym.atom			= atom;
				endSym.type			= N_ENSYM;
				endSym.other		= 1;
				endSym.desc			= 0;
				endSym.value		= 0;
				endSym.string		= "";
				state.stabs.push_back(endSym);
			}
			else {
				ld::relocatable::File::Stab globalsStab;
				const char* name = atom->name();
				if ( atom->scope() == ld::Atom::scopeTranslationUnit ) {
					// Synthesize STSYM stab for statics
					globalsStab.atom		= atom;
					globalsStab.type		= N_STSYM;
					globalsStab.other		= 1;
					globalsStab.desc		= 0;
					globalsStab.value		= 0;
					globalsStab.string		= name;
					state.stabs.push_back(globalsStab);
				}
				else {
					// Synthesize GSYM stab for other globals
					globalsStab.atom		= atom;
					globalsStab.type		= N_GSYM;
					globalsStab.other		= 1;
					globalsStab.desc		= 0;
					globalsStab.value		= 0;
					globalsStab.string		= name;
					state.stabs.push_back(globalsStab);
				}
			}
		}
	}

	if ( wroteStartSO ) {
		//  emit ending SO
		ld::relocatable::File::Stab endFileStab;
		endFileStab.atom		= NULL;
		endFileStab.type		= N_SO;
		endFileStab.other		= 1;
		endFileStab.desc		= 0;
		endFileStab.value		= 0;
		endFileStab.string		= "";
		state.stabs.push_back(endFileStab);
	}

	// copy any stabs from .o files
	bool deadStripping = _options.deadCodeStrip();
	for (const ld::relocatable::File* obj : filesSeenWithStabs) {
		const std::vector<ld::relocatable::File::Stab>* filesStabs = obj->stabs();
		if ( filesStabs != NULL ) {
			for (const ld::relocatable::File::Stab& stab : *filesStabs ) {
				// ignore stabs associated with atoms that were dead stripped or coalesced away
				if ( (stab.atom != NULL) && (atomsWithStabs.count(stab.atom) == 0) )
					continue;
				// <rdar://problem/8284718> Value of N_SO stabs should be address of first atom from translation unit
				if ( (stab.type == N_SO) && (stab.string != NULL) && (stab.string[0] != '\0') ) {
					uint64_t lowestAtomAddress = 0;
					const ld::Atom* lowestAddressAtom = NULL;
					for (const ld::relocatable::File::Stab& stab2 : *filesStabs ) {
						if ( stab2.atom == NULL )
							continue;
						// skip over atoms that were dead stripped
						if ( deadStripping && !stab2.atom->live() )
							continue;
						if ( stab2.atom->coalescedAway() )
							continue;
						uint64_t atomAddr = stab2.atom->objectAddress();
						if ( (lowestAddressAtom == NULL) || (atomAddr < lowestAtomAddress) ) {
							lowestAddressAtom = stab2.atom;
							lowestAtomAddress = atomAddr;
						}
					}
					ld::relocatable::File::Stab altStab = stab;
					altStab.atom = lowestAddressAtom;
					state.stabs.push_back(altStab);
				}
				else {
					state.stabs.push_back(stab);
				}
			}
		}
	}

}


} // namespace tool 
} // namespace ld