]> git.saurik.com Git - apple/ld64.git/blobdiff - src/ld/Options.cpp
ld64-236.3.tar.gz
[apple/ld64.git] / src / ld / Options.cpp
index 6521abebcbf98a7aefe658b35303f0844417ab9e..057fad996b255a41885bce60476c2c430c68b2dc 100644 (file)
@@ -1,6 +1,6 @@
 /* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
  *
- * Copyright (c) 2005-2008 Apple Inc. All rights reserved.
+ * Copyright (c) 2005-2011 Apple Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
  *
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <mach/vm_prot.h>
+#include <sys/sysctl.h>
 #include <mach-o/dyld.h>
 #include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+#include <spawn.h>
+#include <cxxabi.h>
+#include <Availability.h>
+
 #include <vector>
 
-#include "configure.h"
 #include "Options.h"
 #include "Architectures.hpp"
 #include "MachOFileAbstraction.hpp"
+#include "Snapshot.h"
 
-extern void printLTOVersion(Options &opts);
+// upward dependency on lto::version()
+namespace lto {
+       extern const char* version();
+}
 
 // magic to place command line in crash reports
-extern "C" char* __crashreporter_info__;
-static char crashreporterBuffer[1000];
-char* __crashreporter_info__ = crashreporterBuffer;
+const int crashreporterBufferSize = 2000;
+static char crashreporterBuffer[crashreporterBufferSize];
+#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 1070
+       #include <CrashReporterClient.h>
+       // hack until ld does not need to build on 10.6 anymore
+    struct crashreporter_annotations_t gCRAnnotations 
+        __attribute__((section("__DATA," CRASHREPORTER_ANNOTATIONS_SECTION))) 
+        = { CRASHREPORTER_ANNOTATIONS_VERSION, 0, 0, 0, 0, 0, 0 };
+#else
+       extern "C" char* __crashreporter_info__;
+       __attribute__((used)) 
+       char* __crashreporter_info__ = crashreporterBuffer;
+#endif
+
 
 static bool                    sEmitWarnings = true;
+static bool                    sFatalWarnings = false;
 static const char*     sWarningsSideFilePath = NULL;
 static FILE*           sWarningsSideFile = NULL;
+static int                     sWarningsCount = 0;
 
 void warning(const char* format, ...)
 {
+       ++sWarningsCount;
        if ( sEmitWarnings ) {
                va_list list;
                if ( sWarningsSideFilePath != NULL ) {
@@ -80,31 +104,83 @@ void throwf(const char* format, ...)
        throw t;
 }
 
+
+bool Options::FileInfo::checkFileExists(const Options& options, const char *p)
+{
+       struct stat statBuffer;
+       if (p == NULL) 
+         p = path;
+       if ( stat(p, &statBuffer) == 0 ) {
+               if (p != path) path = strdup(p);
+               fileLen = statBuffer.st_size;
+               modTime = statBuffer.st_mtime;
+               return true;
+       }
+       if ( options.dumpDependencyInfo() )
+               options.dumpDependency(Options::depNotFound, p);
+    return false;
+}
+
+
 Options::Options(int argc, const char* argv[])
-       : fOutputFile("a.out"), fArchitecture(0), fSubArchitecture(0), fOutputKind(kDynamicExecutable), 
-         fHasPreferredSubType(false), fPrebind(false), fBindAtLoad(false), fKeepPrivateExterns(false),
+       : fOutputFile("a.out"), fArchitecture(0), fSubArchitecture(0), fArchitectureName("unknown"), fOutputKind(kDynamicExecutable), 
+         fHasPreferredSubType(false), fArchSupportsThumb2(false), fPrebind(false), fBindAtLoad(false), fKeepPrivateExterns(false),
          fNeedsModuleTable(false), fIgnoreOtherArchFiles(false), fErrorOnOtherArchFiles(false), fForceSubtypeAll(false), 
-         fInterposeMode(kInterposeNone), fDeadStrip(kDeadStripOff), fNameSpace(kTwoLevelNameSpace),
-         fDylibCompatVersion(0), fDylibCurrentVersion(0), fDylibInstallName(NULL), fFinalName(NULL), fEntryName("start"), fBaseAddress(0),
+         fInterposeMode(kInterposeNone), fDeadStrip(false), fNameSpace(kTwoLevelNameSpace),
+         fDylibCompatVersion(0), fDylibCurrentVersion(0), fDylibInstallName(NULL), fFinalName(NULL), fEntryName("start"), 
+         fBaseAddress(0), fMaxAddress(0x7FFFFFFFFFFFFFFFLL), 
          fBaseWritableAddress(0), fSplitSegs(false),
-         fExportMode(kExportDefault), fLibrarySearchMode(kSearchAllDirsForDylibsThenAllDirsForArchives),
-         fUndefinedTreatment(kUndefinedError), fMessagesPrefixedWithArchitecture(false), 
+         fExportMode(kExportDefault), fLibrarySearchMode(kSearchDylibAndArchiveInEachDir),
+         fUndefinedTreatment(kUndefinedError), fMessagesPrefixedWithArchitecture(true), 
          fWeakReferenceMismatchTreatment(kWeakReferenceMismatchNonWeak),
          fClientName(NULL),
          fUmbrellaName(NULL), fInitFunctionName(NULL), fDotOutputFile(NULL), fExecutablePath(NULL),
          fBundleLoader(NULL), fDtraceScriptName(NULL), fSegAddrTablePath(NULL), fMapPath(NULL), 
-         fZeroPageSize(ULLONG_MAX), fStackSize(0), fStackAddr(0), fExecutableStack(false), 
+         fDyldInstallPath("/usr/lib/dyld"), fTempLtoObjectPath(NULL), fOverridePathlibLTO(NULL), fLtoCpu(NULL),
+         fZeroPageSize(ULLONG_MAX), fStackSize(0), fStackAddr(0), fSourceVersion(0), fSDKVersion(0), fExecutableStack(false), 
+         fNonExecutableHeap(false), fDisableNonExecutableHeap(false),
          fMinimumHeaderPad(32), fSegmentAlignment(4096), 
          fCommonsMode(kCommonsIgnoreDylibs),  fUUIDMode(kUUIDContent), fLocalSymbolHandling(kLocalSymbolsAll), fWarnCommons(false), 
          fVerbose(false), fKeepRelocations(false), fWarnStabs(false),
          fTraceDylibSearching(false), fPause(false), fStatistics(false), fPrintOptions(false),
          fSharedRegionEligible(false), fPrintOrderFileStatistics(false),  
-         fReadOnlyx86Stubs(false), fPositionIndependentExecutable(false), fMaxMinimumHeaderPad(false),
-         fDeadStripDylibs(false),  fAllowTextRelocs(false), fWarnTextRelocs(false), 
+         fReadOnlyx86Stubs(false), fPositionIndependentExecutable(false), fPIEOnCommandLine(false),
+         fDisablePositionIndependentExecutable(false), fMaxMinimumHeaderPad(false),
+         fDeadStripDylibs(false),  fAllowTextRelocs(false), fWarnTextRelocs(false), fKextsUseStubs(false),
          fUsingLazyDylibLinking(false), fEncryptable(true), 
          fOrderData(true), fMarkDeadStrippableDylib(false),
-         fMakeClassicDyldInfo(true), fMakeCompressedDyldInfo(true), fAllowCpuSubtypeMismatches(false),
-         fUseSimplifiedDylibReExports(false), fSaveTempFiles(false)
+         fMakeCompressedDyldInfo(true), fMakeCompressedDyldInfoForceOff(false), fNoEHLabels(false),
+         fAllowCpuSubtypeMismatches(false), fUseSimplifiedDylibReExports(false),
+         fObjCABIVersion2Override(false), fObjCABIVersion1Override(false), fCanUseUpwardDylib(false),
+         fFullyLoadArchives(false), fLoadAllObjcObjectsFromArchives(false), fFlatNamespace(false),
+         fLinkingMainExecutable(false), fForFinalLinkedImage(false), fForStatic(false),
+         fForDyld(false), fMakeTentativeDefinitionsReal(false), fWhyLoad(false), fRootSafe(false),
+         fSetuidSafe(false), fImplicitlyLinkPublicDylibs(true), fAddCompactUnwindEncoding(true),
+         fWarnCompactUnwind(false), fRemoveDwarfUnwindIfCompactExists(false),
+         fAutoOrderInitializers(true), fOptimizeZeroFill(true), fMergeZeroFill(false), fLogObjectFiles(false),
+         fLogAllFiles(false), fTraceDylibs(false), fTraceIndirectDylibs(false), fTraceArchives(false),
+         fOutputSlidable(false), fWarnWeakExports(false), 
+         fObjcGcCompaction(false), fObjCGc(false), fObjCGcOnly(false), 
+         fDemangle(false), fTLVSupport(false), 
+         fVersionLoadCommand(false), fVersionLoadCommandForcedOn(false), 
+         fVersionLoadCommandForcedOff(false), fFunctionStartsLoadCommand(false),
+         fFunctionStartsForcedOn(false), fFunctionStartsForcedOff(false),
+         fDataInCodeInfoLoadCommand(false), fDataInCodeInfoLoadCommandForcedOn(false), fDataInCodeInfoLoadCommandForcedOff(false),
+         fCanReExportSymbols(false), fObjcCategoryMerging(true), fPageAlignDataAtoms(false), 
+         fNeedsThreadLoadCommand(false), fEntryPointLoadCommand(false),
+         fEntryPointLoadCommandForceOn(false), fEntryPointLoadCommandForceOff(false),
+         fSourceVersionLoadCommand(false), 
+         fSourceVersionLoadCommandForceOn(false), fSourceVersionLoadCommandForceOff(false), 
+         fDependentDRInfo(false), fDependentDRInfoForcedOn(false), fDependentDRInfoForcedOff(false),
+         fTargetIOSSimulator(false), fExportDynamic(false), fAbsoluteSymbols(false),
+         fAllowSimulatorToLinkWithMacOSX(false), fKeepDwarfUnwind(true),
+         fKeepDwarfUnwindForcedOn(false), fKeepDwarfUnwindForcedOff(false),
+         fVerboseOptimizationHints(false), fIgnoreOptimizationHints(false),
+         fGenerateDtraceDOF(true), fAllowBranchIslands(true),
+         fDebugInfoStripping(kDebugInfoMinimal), fTraceOutputFile(NULL), 
+         fMacVersionMin(ld::macVersionUnset), fIOSVersionMin(ld::iOSVersionUnset), 
+         fSaveTempFiles(false), fSnapshotRequested(false), fPipelineFifo(NULL), 
+         fDependencyInfoPath(NULL), fDependencyFileDescriptor(-1)
 {
        this->checkForClassic(argc, argv);
        this->parsePreCommandLineEnvironmentSettings();
@@ -112,54 +188,27 @@ Options::Options(int argc, const char* argv[])
        this->parsePostCommandLineEnvironmentSettings();
        this->reconfigureDefaults();
        this->checkIllegalOptionCombinations();
+       
+       if ( this->dumpDependencyInfo() ) {
+               this->dumpDependency(depOutputFile, fOutputFile);
+               if ( fMapPath != NULL ) 
+               this->dumpDependency(depOutputFile, fMapPath);
+       }
 }
 
 Options::~Options()
 {
+  if ( fDependencyFileDescriptor != -1 )
+       ::close(fDependencyFileDescriptor);
 }
 
-const ObjectFile::ReaderOptions& Options::readerOptions()
-{
-       return fReaderOptions;
-}
-
-
-const char*    Options::getOutputFilePath()
-{
-       return fOutputFile;
-}
-
-std::vector<Options::FileInfo>& Options::getInputFiles()
-{
-       return fInputFiles;
-}
-
-Options::OutputKind    Options::outputKind()
-{
-       return fOutputKind;
-}
-
-bool Options::bindAtLoad()
-{
-       return fBindAtLoad;
-}
-
-bool Options::prebind()
-{
-       return fPrebind;
-}
-
-bool Options::fullyLoadArchives()
+bool Options::errorBecauseOfWarnings() const
 {
-       return fReaderOptions.fFullyLoadArchives;
+       return (sFatalWarnings && (sWarningsCount > 0));
 }
 
-Options::NameSpace Options::nameSpace()
-{
-       return fNameSpace;
-}
 
-const char*    Options::installPath()
+const char*    Options::installPath() const
 {
        if ( fDylibInstallName != NULL )
                return fDylibInstallName;
@@ -169,32 +218,8 @@ const char*        Options::installPath()
                return fOutputFile;
 }
 
-uint32_t Options::currentVersion()
-{
-       return fDylibCurrentVersion;
-}
-
-uint32_t Options::compatibilityVersion()
-{
-       return fDylibCompatVersion;
-}
-
-const char*    Options::entryName()
-{
-       return fEntryName;
-}
-
-uint64_t Options::baseAddress()
-{
-       return fBaseAddress;
-}
-
-bool Options::keepPrivateExterns()
-{
-       return fKeepPrivateExterns;
-}
 
-bool Options::interposable(const char* name)
+bool Options::interposable(const char* name) const
 {
        switch ( fInterposeMode ) {
                case kInterposeNone:
@@ -207,121 +232,32 @@ bool Options::interposable(const char* name)
        throw "internal error";
 }
 
-bool Options::needsModuleTable()
-{
-       return fNeedsModuleTable;
-}
-
-bool Options::ignoreOtherArchInputFiles()
-{
-       return fIgnoreOtherArchFiles;
-}
-
-bool Options::forceCpuSubtypeAll()
-{
-       return fForceSubtypeAll;
-}
-
-bool Options::traceDylibs()
-{
-       return fReaderOptions.fTraceDylibs;
-}
-
-bool Options::traceArchives()
-{
-       return fReaderOptions.fTraceArchives;
-}
-
-Options::UndefinedTreatment Options::undefinedTreatment()
-{
-       return fUndefinedTreatment;
-}
-
-Options::WeakReferenceMismatchTreatment        Options::weakReferenceMismatchTreatment()
-{
-       return fWeakReferenceMismatchTreatment;
-}
-
-const char* Options::umbrellaName()
-{
-       return fUmbrellaName;
-}
-
-std::vector<const char*>& Options::allowableClients()
-{
-       return fAllowableClients;
-}
-
-const char* Options::clientName()
-{
-       return fClientName;
-}
-
-uint64_t Options::zeroPageSize()
-{
-       return fZeroPageSize;
-}
-
-bool Options::hasCustomStack()
-{
-       return (fStackSize != 0);
-}
-
-uint64_t Options::customStackSize()
-{
-       return fStackSize;
-}
-
-uint64_t Options::customStackAddr()
-{
-       return fStackAddr;
-}
-
-bool Options::hasExecutableStack()
-{
-       return fExecutableStack;
-}
-
-std::vector<const char*>& Options::initialUndefines()
-{
-       return fInitialUndefines;
-}
 
-bool Options::printWhyLive(const char* symbolName)
+bool Options::printWhyLive(const char* symbolName) const
 {
        return ( fWhyLive.find(symbolName) != fWhyLive.end() );
 }
 
 
-const char*    Options::initFunctionName()
-{
-       return fInitFunctionName;
-}
-
 const char*    Options::dotOutputFile()
 {
        return fDotOutputFile;
 }
 
-bool Options::hasExportRestrictList()
-{
-       return (fExportMode != kExportDefault);
-}
 
-bool Options::hasExportMaskList()
+bool Options::hasWildCardExportRestrictList() const
 {
-       return (fExportMode == kExportSome);
+       // has -exported_symbols_list which contains some wildcards
+       return ((fExportMode == kExportSome) && fExportSymbols.hasWildCards());
 }
 
-
-bool Options::hasWildCardExportRestrictList()
+bool Options::hasWeakBitTweaks() const
 {
        // has -exported_symbols_list which contains some wildcards
-       return ((fExportMode == kExportSome) && fExportSymbols.hasWildCards());
+       return (!fForceWeakSymbols.empty() || !fForceNotWeakSymbols.empty());
 }
 
-
-bool Options::allGlobalsAreDeadStripRoots()
+bool Options::allGlobalsAreDeadStripRoots() const
 {
        // -exported_symbols_list means globals are not exported by default
        if ( fExportMode == kExportSome )
@@ -329,7 +265,11 @@ bool Options::allGlobalsAreDeadStripRoots()
        //
        switch ( fOutputKind ) {
                case Options::kDynamicExecutable:
+                       // <rdar://problem/12839986> Add the -export_dynamic flag 
+                       return fExportDynamic;
                case Options::kStaticExecutable:
+                       // <rdar://problem/13361218> Support the -export_dynamic flag for xnu
+                       return fExportDynamic;
                case Options::kPreload:
                        // by default unused globals in a main executable are stripped
                        return false;
@@ -343,59 +283,122 @@ bool Options::allGlobalsAreDeadStripRoots()
        return false;
 }
 
-uint32_t Options::minimumHeaderPad()
+
+bool Options::keepRelocations()
 {
-       return fMinimumHeaderPad;
+       return fKeepRelocations;
 }
 
-std::vector<Options::ExtraSection>&    Options::extraSections()
+bool Options::warnStabs()
 {
-       return fExtraSections;
+       return fWarnStabs;
 }
 
-std::vector<Options::SectionAlignment>&        Options::sectionAlignments()
+const char* Options::executablePath()
 {
-       return fSectionAlignments;
+       return fExecutablePath;
 }
 
-Options::CommonsMode Options::commonsMode()
+uint32_t Options::initialSegProtection(const char* segName) const
 {
-       return fCommonsMode;
+       for(std::vector<Options::SegmentProtect>::const_iterator it = fCustomSegmentProtections.begin(); it != fCustomSegmentProtections.end(); ++it) {
+               if ( strcmp(it->name, segName) == 0 ) {
+                       return it->init;
+               }
+       }
+       if ( strcmp(segName, "__PAGEZERO") == 0 ) {
+               return 0;
+       }
+       else if ( strcmp(segName, "__TEXT") == 0 ) {
+               return VM_PROT_READ | VM_PROT_EXECUTE;
+       }
+       else if ( strcmp(segName, "__LINKEDIT") == 0 ) {
+               return VM_PROT_READ;
+       }
+       
+       // all others default to read-write
+       return VM_PROT_READ | VM_PROT_WRITE;
 }
 
-bool Options::warnCommons()
+uint32_t Options::maxSegProtection(const char* segName) const
+{
+       // iPhoneOS always uses same protection for max and initial
+       // <rdar://problem/11663436> simulator apps need to use MacOSX max-prot
+       if ( (fIOSVersionMin != ld::iOSVersionUnset) && (fArchitecture != CPU_TYPE_I386) )
+               return initialSegProtection(segName);
+
+       for(std::vector<Options::SegmentProtect>::const_iterator it = fCustomSegmentProtections.begin(); it != fCustomSegmentProtections.end(); ++it) {
+               if ( strcmp(it->name, segName) == 0 ) {
+                       return it->max;
+               }
+       }
+       if ( strcmp(segName, "__PAGEZERO") == 0 ) {
+               return 0;
+       }
+       // all others default to all
+       return VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE;
+}
+       
+uint64_t Options::segPageSize(const char* segName) const
 {
-       return fWarnCommons;
+       for(std::vector<SegmentSize>::const_iterator it=fCustomSegmentSizes.begin(); it != fCustomSegmentSizes.end(); ++it) {
+               if ( strcmp(it->name, segName) == 0 )
+                       return it->size;
+       }
+       return fSegmentAlignment;
 }
 
-bool Options::keepRelocations()
+uint64_t Options::customSegmentAddress(const char* segName) const
 {
-       return fKeepRelocations;
+       for(std::vector<SegmentStart>::const_iterator it=fCustomSegmentAddresses.begin(); it != fCustomSegmentAddresses.end(); ++it) {
+               if ( strcmp(it->name, segName) == 0 )
+                       return it->address;
+       }
+       // if custom stack in use, model as segment with custom address
+       if ( (fStackSize != 0) && (strcmp("__UNIXSTACK", segName) == 0) )
+               return fStackAddr - fStackSize;
+       return 0;
 }
 
-bool Options::warnStabs()
+bool Options::hasCustomSegmentAddress(const char* segName) const
 {
-       return fWarnStabs;
+       for(std::vector<SegmentStart>::const_iterator it=fCustomSegmentAddresses.begin(); it != fCustomSegmentAddresses.end(); ++it) {
+               if ( strcmp(it->name, segName) == 0 )
+                       return true;
+       }
+       // if custom stack in use, model as segment with custom address
+       if ( (fStackSize != 0) && (strcmp("__UNIXSTACK", segName) == 0) )
+               return true;
+       return false;
 }
 
-const char* Options::executablePath()
+bool Options::hasCustomSectionAlignment(const char* segName, const char* sectName) const
 {
-       return fExecutablePath;
+       for (std::vector<SectionAlignment>::const_iterator it = fSectionAlignments.begin(); it != fSectionAlignments.end(); ++it) {
+               if ( (strcmp(it->segmentName, segName) == 0) && (strcmp(it->sectionName, sectName) == 0) )
+                       return true;
+       }
+       return false;
 }
 
-Options::DeadStripMode Options::deadStrip()
+uint8_t Options::customSectionAlignment(const char* segName, const char* sectName) const
 {
-       return fDeadStrip;
+       for (std::vector<SectionAlignment>::const_iterator it = fSectionAlignments.begin(); it != fSectionAlignments.end(); ++it) {
+               if ( (strcmp(it->segmentName, segName) == 0) && (strcmp(it->sectionName, sectName) == 0) )
+                       return it->alignment;
+       }
+       return 0;
 }
 
+
 bool Options::hasExportedSymbolOrder()
 {
        return (fExportSymbolsOrder.size() > 0);
 }
 
-bool Options::exportedSymbolOrder(const char* sym, unsigned int* order)
+bool Options::exportedSymbolOrder(const char* sym, unsigned int* order) const
 {
-       NameToOrder::iterator pos = fExportSymbolsOrder.find(sym);
+       NameToOrder::const_iterator pos = fExportSymbolsOrder.find(sym);
        if ( pos != fExportSymbolsOrder.end() ) {
                *order = pos->second;
                return true;
@@ -423,7 +426,7 @@ void Options::loadSymbolOrderFile(const char* fileOfExports, NameToOrder& orderM
 
        ::close(fd);
 
-       // parse into symbols and add to hash_set
+       // parse into symbols and add to unordered_set
        unsigned int count = 0;
        char * const end = &p[stat_buf.st_size];
        enum { lineStart, inSymbol, inComment } state = lineStart;
@@ -477,8 +480,33 @@ void Options::loadSymbolOrderFile(const char* fileOfExports, NameToOrder& orderM
        // Note: we do not free() the malloc buffer, because the strings are used by the export-set hash table
 }
 
+bool Options::forceWeak(const char* symbolName) const
+{
+       return fForceWeakSymbols.contains(symbolName);
+}
+
+bool Options::forceNotWeak(const char* symbolName) const
+{
+       return fForceNotWeakSymbols.contains(symbolName);
+}
+
+bool Options::forceWeakNonWildCard(const char* symbolName) const
+{
+       return fForceWeakSymbols.containsNonWildcard(symbolName);
+}
+
+bool Options::forceNotWeakNonWildcard(const char* symbolName) const
+{
+       return fForceNotWeakSymbols.containsNonWildcard(symbolName);
+}
+
+bool Options::forceCoalesce(const char* symbolName) const
+{
+       return fForceCoalesceSymbols.contains(symbolName);
+}
+
 
-bool Options::shouldExport(const char* symbolName)
+bool Options::shouldExport(const char* symbolName) const
 {
        switch (fExportMode) {
                case kExportSome:
@@ -491,7 +519,12 @@ bool Options::shouldExport(const char* symbolName)
        throw "internal error";
 }
 
-bool Options::keepLocalSymbol(const char* symbolName)
+bool Options::shouldReExport(const char* symbolName) const
+{
+       return fReExportSymbols.contains(symbolName);
+}
+
+bool Options::keepLocalSymbol(const char* symbolName) const
 {
        switch (fLocalSymbolHandling) {
                case kLocalSymbolsAll:
@@ -506,105 +539,91 @@ bool Options::keepLocalSymbol(const char* symbolName)
        throw "internal error";
 }
 
-void Options::parseArch(const char* architecture)
+void Options::setArchitecture(cpu_type_t type, cpu_subtype_t subtype)
 {
-       if ( architecture == NULL )
+       for (const ArchInfo* t=archInfoArray; t->archName != NULL; ++t) {
+               if ( (type == t->cpuType) && (subtype == t->cpuSubType) ) {
+                       fArchitecture = type;
+                       fSubArchitecture = subtype;
+                       fArchitectureName = t->archName;
+                       fHasPreferredSubType = t->isSubType;
+                       fArchSupportsThumb2 = t->supportsThumb2;
+                       switch ( type ) {
+                               case CPU_TYPE_I386:
+                               case CPU_TYPE_X86_64:
+                                       if ( (fMacVersionMin == ld::macVersionUnset) && (fIOSVersionMin == ld::iOSVersionUnset) && (fOutputKind != Options::kObjectFile) ) {
+                               #ifdef DEFAULT_MACOSX_MIN_VERSION
+                                               warning("-macosx_version_min not specified, assuming " DEFAULT_MACOSX_MIN_VERSION);
+                                               setMacOSXVersionMin(DEFAULT_MACOSX_MIN_VERSION);
+                               #else
+                                               warning("-macosx_version_min not specified, assuming 10.6");
+                                               fMacVersionMin = ld::mac10_6;
+                               #endif          
+                                       }
+                                       break;
+                               case CPU_TYPE_ARM:
+                               case CPU_TYPE_ARM64:
+                                       if ( (fMacVersionMin == ld::macVersionUnset) && (fIOSVersionMin == ld::iOSVersionUnset) && (fOutputKind != Options::kObjectFile) ) {
+                               #if defined(DEFAULT_IPHONEOS_MIN_VERSION)
+                                               warning("-ios_version_min not specified, assuming " DEFAULT_IPHONEOS_MIN_VERSION);
+                                               setIOSVersionMin(DEFAULT_IPHONEOS_MIN_VERSION);
+                               #else
+                                               warning("-ios_version_min not specified, assuming 6.0");
+                                               setIOSVersionMin("6.0");
+                               #endif
+                                       }
+                                       break;
+                       }
+                       fLinkSnapshot.recordArch(fArchitectureName);
+                       // only use compressed LINKEDIT for:
+                       //                      Mac OS X 10.6 or later
+                       //                      iOS 3.1 or later
+                       if ( !fMakeCompressedDyldInfo && minOS(ld::mac10_6, ld::iOS_3_1) && !fMakeCompressedDyldInfoForceOff )
+                               fMakeCompressedDyldInfo = true;
+                       // Mac OS X 10.5 and iPhoneOS 2.0 support LC_REEXPORT_DYLIB
+                       if ( minOS(ld::mac10_5, ld::iOS_2_0) )
+                               fUseSimplifiedDylibReExports = true;
+                       return;
+               }
+       }
+       fArchitectureName = "unknown architecture";
+}
+
+void Options::parseArch(const char* arch)
+{
+       if ( arch == NULL )
                throw "-arch must be followed by an architecture string";
-       if ( strcmp(architecture, "ppc") == 0 ) {
-               fArchitecture = CPU_TYPE_POWERPC;
-               fSubArchitecture = CPU_SUBTYPE_POWERPC_ALL;
-       }
-       else if ( strcmp(architecture, "ppc64") == 0 ) {
-               fArchitecture = CPU_TYPE_POWERPC64;
-               fSubArchitecture = CPU_SUBTYPE_POWERPC_ALL;
-       }
-       else if ( strcmp(architecture, "i386") == 0 ) {
-               fArchitecture = CPU_TYPE_I386;
-               fSubArchitecture = CPU_SUBTYPE_I386_ALL;
-       }
-       else if ( strcmp(architecture, "x86_64") == 0 ) {
-               fArchitecture = CPU_TYPE_X86_64;
-               fSubArchitecture = CPU_SUBTYPE_X86_64_ALL;
-       }
-       else if ( strcmp(architecture, "arm") == 0 ) {
-               fArchitecture = CPU_TYPE_ARM;
-               fSubArchitecture = CPU_SUBTYPE_ARM_ALL;
-       }
-       // compatibility support for cpu-sub-types
-       else if ( strcmp(architecture, "ppc750") == 0 ) {
-               fArchitecture = CPU_TYPE_POWERPC;
-               fSubArchitecture = CPU_SUBTYPE_POWERPC_750;
-               fHasPreferredSubType = true;
-       }
-       else if ( strcmp(architecture, "ppc7400") == 0 ) {
-               fArchitecture = CPU_TYPE_POWERPC;
-               fSubArchitecture = CPU_SUBTYPE_POWERPC_7400;
-               fHasPreferredSubType = true;
-       }
-       else if ( strcmp(architecture, "ppc7450") == 0 ) {
-               fArchitecture = CPU_TYPE_POWERPC;
-               fSubArchitecture = CPU_SUBTYPE_POWERPC_7450;
-               fHasPreferredSubType = true;
-       }
-       else if ( strcmp(architecture, "ppc970") == 0 ) {
-               fArchitecture = CPU_TYPE_POWERPC;
-               fSubArchitecture = CPU_SUBTYPE_POWERPC_970;
-               fHasPreferredSubType = true;
-       }
-       else if ( strcmp(architecture, "armv6") == 0 ) {
-               fArchitecture = CPU_TYPE_ARM;
-               fSubArchitecture = CPU_SUBTYPE_ARM_V6;
-               fHasPreferredSubType = true;
-       }
-       else if ( strcmp(architecture, "armv5") == 0 ) {
-               fArchitecture = CPU_TYPE_ARM;
-               fSubArchitecture = CPU_SUBTYPE_ARM_V5TEJ;
-               fHasPreferredSubType = true;
-       }
-       else if ( strcmp(architecture, "armv4t") == 0 ) {
-               fArchitecture = CPU_TYPE_ARM;
-               fSubArchitecture = CPU_SUBTYPE_ARM_V4T;
-               fHasPreferredSubType = true;
-       }
-       else if ( strcmp(architecture, "xscale") == 0 ) {
-               fArchitecture = CPU_TYPE_ARM;
-               fSubArchitecture = CPU_SUBTYPE_ARM_XSCALE;
-               fHasPreferredSubType = true;
-       }
-       else if ( strcmp(architecture, "armv7") == 0 ) {
-               fArchitecture = CPU_TYPE_ARM;
-               fSubArchitecture = CPU_SUBTYPE_ARM_V7;
-               fHasPreferredSubType = true;
+       for (const ArchInfo* t=archInfoArray; t->archName != NULL; ++t) {
+               if ( strcmp(t->archName,arch) == 0 ) {
+                       fArchitectureName = arch;
+                       fArchitecture = t->cpuType;
+                       fSubArchitecture = t->cpuSubType;
+                       fHasPreferredSubType = t->isSubType;
+                       fArchSupportsThumb2 = t->supportsThumb2;
+                       return;
+               }
        }
-       else
-               throwf("unknown/unsupported architecture name for: -arch %s", architecture);
+       throwf("unknown/unsupported architecture name for: -arch %s", arch);
 }
 
-bool Options::checkForFile(const char* format, const char* dir, const char* rootName, FileInfo& result)
+bool Options::checkForFile(const char* format, const char* dir, const char* rootName, FileInfo& result) const
 {
-       struct stat statBuffer;
        char possiblePath[strlen(dir)+strlen(rootName)+strlen(format)+8];
        sprintf(possiblePath, format,  dir, rootName);
-       bool found = (stat(possiblePath, &statBuffer) == 0);
+       bool found = result.checkFileExists(*this, possiblePath);
        if ( fTraceDylibSearching )
                printf("[Logging for XBS]%sfound library: '%s'\n", (found ? " " : " not "), possiblePath);
-       if ( found ) {
-               result.path = strdup(possiblePath);
-               result.fileLen = statBuffer.st_size;
-               result.modTime = statBuffer.st_mtime;
-               return true;
-       }
-       return false;
+       return found;
 }
 
 
-Options::FileInfo Options::findLibrary(const char* rootName, bool dylibsOnly)
+Options::FileInfo Options::findLibrary(const char* rootName, bool dylibsOnly) const
 {
        FileInfo result;
        const int rootNameLen = strlen(rootName);
        // if rootName ends in .o there is no .a vs .dylib choice
        if ( (rootNameLen > 3) && (strcmp(&rootName[rootNameLen-2], ".o") == 0) ) {
-               for (std::vector<const char*>::iterator it = fLibrarySearchPaths.begin();
+               for (std::vector<const char*>::const_iterator it = fLibrarySearchPaths.begin();
                         it != fLibrarySearchPaths.end();
                         it++) {
                        const char* dir = *it;
@@ -613,19 +632,33 @@ Options::FileInfo Options::findLibrary(const char* rootName, bool dylibsOnly)
                }
        }
        else {
-               bool lookForDylibs = ( fOutputKind != Options::kDyld);
+               bool lookForDylibs = false;
+               switch ( fOutputKind ) {
+                       case Options::kDynamicExecutable:
+                       case Options::kDynamicLibrary:
+                       case Options::kDynamicBundle:
+                       case Options::kObjectFile:  // <rdar://problem/15914513> 
+                               lookForDylibs = true;
+                               break;
+                       case Options::kStaticExecutable:
+                       case Options::kDyld:
+                       case Options::kPreload:
+                       case Options::kKextBundle:
+                               lookForDylibs = false;
+                               break;
+               }
                switch ( fLibrarySearchMode ) {
                case kSearchAllDirsForDylibsThenAllDirsForArchives:
                                // first look in all directories for just for dylibs
                                if ( lookForDylibs ) {
-                                       for (std::vector<const char*>::iterator it = fLibrarySearchPaths.begin();
+                                       for (std::vector<const char*>::const_iterator it = fLibrarySearchPaths.begin();
                                                 it != fLibrarySearchPaths.end();
                                                 it++) {
                                                const char* dir = *it;
                                                if ( checkForFile("%s/lib%s.dylib", dir, rootName, result) )
                                                        return result;
                                        }
-                                       for (std::vector<const char*>::iterator it = fLibrarySearchPaths.begin();
+                                       for (std::vector<const char*>::const_iterator it = fLibrarySearchPaths.begin();
                                                 it != fLibrarySearchPaths.end();
                                                 it++) {
                                                const char* dir = *it;
@@ -635,7 +668,7 @@ Options::FileInfo Options::findLibrary(const char* rootName, bool dylibsOnly)
                                }
                                // next look in all directories for just for archives
                                if ( !dylibsOnly ) {
-                                       for (std::vector<const char*>::iterator it = fLibrarySearchPaths.begin();
+                                       for (std::vector<const char*>::const_iterator it = fLibrarySearchPaths.begin();
                                                 it != fLibrarySearchPaths.end();
                                                 it++) {
                                                const char* dir = *it;
@@ -647,7 +680,7 @@ Options::FileInfo Options::findLibrary(const char* rootName, bool dylibsOnly)
 
                        case kSearchDylibAndArchiveInEachDir:
                                // look in each directory for just for a dylib then for an archive
-                               for (std::vector<const char*>::iterator it = fLibrarySearchPaths.begin();
+                               for (std::vector<const char*>::const_iterator it = fLibrarySearchPaths.begin();
                                         it != fLibrarySearchPaths.end();
                                         it++) {
                                        const char* dir = *it;
@@ -664,7 +697,7 @@ Options::FileInfo Options::findLibrary(const char* rootName, bool dylibsOnly)
        throwf("library not found for -l%s", rootName);
 }
 
-Options::FileInfo Options::findFramework(const char* frameworkName)
+Options::FileInfo Options::findFramework(const char* frameworkName) const
 {
        if ( frameworkName == NULL )
                throw "-framework missing next argument";
@@ -680,10 +713,9 @@ Options::FileInfo Options::findFramework(const char* frameworkName)
        return findFramework(name, suffix);
 }
 
-Options::FileInfo Options::findFramework(const char* rootName, const char* suffix)
+Options::FileInfo Options::findFramework(const char* rootName, const char* suffix) const
 {
-       struct stat statBuffer;
-       for (std::vector<const char*>::iterator it = fFrameworkSearchPaths.begin();
+       for (std::vector<const char*>::const_iterator it = fFrameworkSearchPaths.begin();
                 it != fFrameworkSearchPaths.end();
                 it++) {
                // ??? Shouldn't we be using String here and just initializing it?
@@ -703,15 +735,12 @@ Options::FileInfo Options::findFramework(const char* rootName, const char* suffi
                                strcat(possiblePath, suffix);
                        }
                }
-               bool found = (stat(possiblePath, &statBuffer) == 0);
+        FileInfo result;
+               bool found = result.checkFileExists(*this, possiblePath);
                if ( fTraceDylibSearching )
                        printf("[Logging for XBS]%sfound framework: '%s'\n",
                                   (found ? " " : " not "), possiblePath);
                if ( found ) {
-                       FileInfo result;
-                       result.path = strdup(possiblePath);
-                       result.fileLen = statBuffer.st_size;
-                       result.modTime = statBuffer.st_mtime;
                        return result;
                }
        }
@@ -722,15 +751,14 @@ Options::FileInfo Options::findFramework(const char* rootName, const char* suffi
                throwf("framework not found %s", rootName);
 }
 
-Options::FileInfo Options::findFile(const char* path)
+Options::FileInfo Options::findFile(const char* path) const
 {
        FileInfo result;
-       struct stat statBuffer;
 
        // if absolute path and not a .o file, the use SDK prefix
        if ( (path[0] == '/') && (strcmp(&path[strlen(path)-2], ".o") != 0) ) {
                const int pathLen = strlen(path);
-               for (std::vector<const char*>::iterator it = fSDKPaths.begin(); it != fSDKPaths.end(); it++) {
+               for (std::vector<const char*>::const_iterator it = fSDKPaths.begin(); it != fSDKPaths.end(); it++) {
                        // ??? Shouldn't we be using String here?
                        const char* sdkPathDir = *it;
                        const int sdkPathDirLen = strlen(sdkPathDir);
@@ -739,19 +767,13 @@ Options::FileInfo Options::findFile(const char* path)
                        if ( possiblePath[sdkPathDirLen-1] == '/' )
                                possiblePath[sdkPathDirLen-1] = '\0';
                        strcat(possiblePath, path);
-                       if ( stat(possiblePath, &statBuffer) == 0 ) {
-                               result.path = strdup(possiblePath);
-                               result.fileLen = statBuffer.st_size;
-                               result.modTime = statBuffer.st_mtime;
+                       if ( result.checkFileExists(*this, possiblePath) ) {
                                return result;
                        }
                }
        }
        // try raw path
-       if ( stat(path, &statBuffer) == 0 ) {
-               result.path = strdup(path);
-               result.fileLen = statBuffer.st_size;
-               result.modTime = statBuffer.st_mtime;
+       if ( result.checkFileExists(*this, path) ) {
                return result;
        }
 
@@ -764,10 +786,7 @@ Options::FileInfo Options::findFile(const char* path)
                        strcpy(&addPoint[1], &path[17]);
                else
                        strcpy(newPath, &path[17]);
-               if ( stat(newPath, &statBuffer) == 0 ) {
-                       result.path = strdup(newPath);
-                       result.fileLen = statBuffer.st_size;
-                       result.modTime = statBuffer.st_mtime;
+               if ( result.checkFileExists(*this, newPath) ) {
                        return result;
                }
        }
@@ -776,7 +795,7 @@ Options::FileInfo Options::findFile(const char* path)
        throwf("file not found: %s", path);
 }
 
-Options::FileInfo Options::findFileUsingPaths(const char* path)
+Options::FileInfo Options::findFileUsingPaths(const char* path) const 
 {
        FileInfo result;
 
@@ -802,7 +821,7 @@ Options::FileInfo Options::findFileUsingPaths(const char* path)
        // don't need to try variations, just paths. We do need to add the additional bits
        // onto the framework path though.
        if ( isFramework ) {
-               for (std::vector<const char*>::iterator it = fFrameworkSearchPaths.begin();
+               for (std::vector<const char*>::const_iterator it = fFrameworkSearchPaths.begin();
                         it != fFrameworkSearchPaths.end();
                         it++) {
                        const char* dir = *it;
@@ -825,7 +844,7 @@ Options::FileInfo Options::findFileUsingPaths(const char* path)
                                        && (strcmp(&leafName[leafLen-6], ".dylib") == 0) 
                                        && (strstr(path, ".framework/") != NULL) );
                if ( !embeddedDylib ) {
-                       for (std::vector<const char*>::iterator it = fLibrarySearchPaths.begin();
+                       for (std::vector<const char*>::const_iterator it = fLibrarySearchPaths.begin();
                                 it != fLibrarySearchPaths.end();
                                 it++) {
                                const char* dir = *it;
@@ -839,9 +858,10 @@ Options::FileInfo Options::findFileUsingPaths(const char* path)
        // If we didn't find it fall back to findFile.
        return findFile(path);
 }
 
-void Options::parseSegAddrTable(const char* segAddrPath, const char* installPath)
+
+
+void Options::parseSegAddrTable(const char* segAddrPath, const char* installPth)
 {
        FILE* file = fopen(segAddrPath, "r");
        if ( file == NULL ) {
@@ -878,7 +898,7 @@ void Options::parseSegAddrTable(const char* segAddrPath, const char* installPath
                                for(char* end = eol-1; (end > p) && isspace(*end); --end)
                                        *end = '\0';
                                // see if this line is for the dylib being linked
-                               if ( strcmp(p, installPath) == 0 ) {
+                               if ( strcmp(p, installPth) == 0 ) {
                                        fBaseAddress = firstColumAddress;
                                        if ( hasSecondColumn ) {
                                                fBaseWritableAddress = secondColumAddress;
@@ -893,7 +913,7 @@ void Options::parseSegAddrTable(const char* segAddrPath, const char* installPath
        fclose(file);
 }
 
-void Options::loadFileList(const char* fileOfPaths)
+void Options::loadFileList(const char* fileOfPaths, ld::File::Ordinal baseOrdinal)
 {
        FILE* file;
        const char* comma = strrchr(fileOfPaths, ',');
@@ -909,16 +929,21 @@ void Options::loadFileList(const char* fileOfPaths)
                        realFileOfPaths[realFileOfPathsLen] = '\0';
                        file = fopen(realFileOfPaths, "r");
                        if ( file == NULL )
-                               throwf("-filelist file not found: %s\n", realFileOfPaths);
+                               throwf("-filelist file '%s' could not be opened, errno=%d (%s)\n", realFileOfPaths, errno, strerror(errno));
+                       if ( this->dumpDependencyInfo() )
+                               this->dumpDependency(Options::depFileList, realFileOfPaths);
                }
        }
        else {
                file = fopen(fileOfPaths, "r");
                if ( file == NULL )
-                       throwf("-filelist file not found: %s\n", fileOfPaths);
+                       throwf("-filelist file '%s' could not be opened, errno=%d (%s)\n", fileOfPaths, errno, strerror(errno));
+               if ( this->dumpDependencyInfo() )
+                       this->dumpDependency(Options::depFileList, fileOfPaths);
        }
 
        char path[PATH_MAX];
+       ld::File::Ordinal previousOrdinal = baseOrdinal;
        while ( fgets(path, PATH_MAX, file) != NULL ) {
                path[PATH_MAX-1] = '\0';
                char* eol = strchr(path, '\n');
@@ -929,16 +954,51 @@ void Options::loadFileList(const char* fileOfPaths)
                        strcpy(builtPath, prefix);
                        strcat(builtPath, "/");
                        strcat(builtPath, path);
-                       fInputFiles.push_back(findFile(builtPath));
+           if (fPipelineFifo != NULL) {
+                          FileInfo info = FileInfo(builtPath);
+                          info.ordinal = previousOrdinal.nextFileListOrdinal();
+                          previousOrdinal = info.ordinal;
+                          info.fromFileList = true;
+              fInputFiles.push_back(info);
+           } else {
+                          FileInfo info = findFile(builtPath);
+                          info.ordinal = previousOrdinal.nextFileListOrdinal();
+                          previousOrdinal = info.ordinal;
+                          info.fromFileList = true;
+                          fInputFiles.push_back(info);
+           }
                }
                else {
-                       fInputFiles.push_back(findFile(path));
+           if (fPipelineFifo != NULL) {
+                          FileInfo info = FileInfo(path);
+                          info.ordinal = previousOrdinal.nextFileListOrdinal();
+                          previousOrdinal = info.ordinal;
+                          info.fromFileList = true;
+                          fInputFiles.push_back(info);
+           } else {
+                          FileInfo info = findFile(path);
+                          info.ordinal = previousOrdinal.nextFileListOrdinal();
+                          previousOrdinal = info.ordinal;
+                          info.fromFileList = true;
+                          fInputFiles.push_back(info);
+           }
                }
        }
        fclose(file);
 }
 
-bool Options::SetWithWildcards::hasWildCards(const char* symbol)
+
+void Options::SetWithWildcards::remove(const NameSet& toBeRemoved)
+{
+       for(NameSet::const_iterator it=toBeRemoved.begin(); it != toBeRemoved.end(); ++it) {
+               const char* symbolName = *it;
+               NameSet::iterator pos = fRegular.find(symbolName);
+               if ( pos != fRegular.end() )
+                       fRegular.erase(pos);
+       }
+}
+
+bool Options::SetWithWildcards::hasWildCards(const char* symbol) 
 {
        // an exported symbol name containing *, ?, or [ requires wildcard matching
        return ( strpbrk(symbol, "*?[") != NULL );
@@ -952,21 +1012,28 @@ void Options::SetWithWildcards::insert(const char* symbol)
                fRegular.insert(symbol);
 }
 
-bool Options::SetWithWildcards::contains(const char* symbol)
+bool Options::SetWithWildcards::contains(const char* symbol) const
 {
        // first look at hash table on non-wildcard symbols
        if ( fRegular.find(symbol) != fRegular.end() )
                return true;
        // next walk list of wild card symbols looking for a match
-       for(std::vector<const char*>::iterator it = fWildCard.begin(); it != fWildCard.end(); ++it) {
+       for(std::vector<const char*>::const_iterator it = fWildCard.begin(); it != fWildCard.end(); ++it) {
                if ( wildCardMatch(*it, symbol) )
                        return true;
        }
        return false;
 }
 
+bool Options::SetWithWildcards::containsNonWildcard(const char* symbol) const
+{
+       // look at hash table on non-wildcard symbols
+       return ( fRegular.find(symbol) != fRegular.end() );
+}
+
 
-bool Options::SetWithWildcards::inCharRange(const char*& p, unsigned char c)
+
+bool Options::SetWithWildcards::inCharRange(const char*& p, unsigned char c) const
 {
        ++p; // find end
        const char* b = p;
@@ -995,7 +1062,7 @@ bool Options::SetWithWildcards::inCharRange(const char*& p, unsigned char c)
        return false;
 }
 
-bool Options::SetWithWildcards::wildCardMatch(const char* pattern, const char* symbol)
+bool Options::SetWithWildcards::wildCardMatch(const char* pattern, const char* symbol) const
 {
        const char* s = symbol;
        for (const char* p = pattern; *p != '\0'; ++p) {
@@ -1030,6 +1097,8 @@ bool Options::SetWithWildcards::wildCardMatch(const char* pattern, const char* s
 
 void Options::loadExportFile(const char* fileOfExports, const char* option, SetWithWildcards& set)
 {
+       if ( fileOfExports == NULL )
+               throwf("missing file after %s", option);
        // read in whole file
        int fd = ::open(fileOfExports, O_RDONLY, 0);
        if ( fd == -1 )
@@ -1043,9 +1112,12 @@ void Options::loadExportFile(const char* fileOfExports, const char* option, SetW
        if ( read(fd, p, stat_buf.st_size) != stat_buf.st_size )
                throwf("can't read %s file: %s", option, fileOfExports);
 
+       if ( this->dumpDependencyInfo() )
+               this->dumpDependency(Options::depMisc, fileOfExports);
+
        ::close(fd);
 
-       // parse into symbols and add to hash_set
+       // parse into symbols and add to unordered_set
        char * const end = &p[stat_buf.st_size];
        enum { lineStart, inSymbol, inComment } state = lineStart;
        char* symbolStart = NULL;
@@ -1114,9 +1186,11 @@ void Options::parseAliasFile(const char* fileOfAliases)
                throwf("can't read alias file: %s", fileOfAliases);
        p[stat_buf.st_size] = '\n';
        ::close(fd);
+       if ( this->dumpDependencyInfo() )
+               this->dumpDependency(Options::depMisc, fileOfAliases);
 
        // parse into symbols and add to fAliases
-       ObjectFile::ReaderOptions::AliasPair pair;
+       AliasPair pair;
        char * const end = &p[stat_buf.st_size+1];
        enum { lineStart, inRealName, inBetween, inAliasName, inComment } state = lineStart;
        int lineNumber = 1;
@@ -1162,7 +1236,7 @@ void Options::parseAliasFile(const char* fileOfAliases)
                                        *last = '\0';
                                        --last;
                                }
-                               fReaderOptions.fAliases.push_back(pair);
+                               fAliases.push_back(pair);
                                state = inComment;
                        }
                        else if ( *s == '\n' ) {
@@ -1173,7 +1247,7 @@ void Options::parseAliasFile(const char* fileOfAliases)
                                        *last = '\0';
                                        --last;
                                }
-                               fReaderOptions.fAliases.push_back(pair);
+                               fAliases.push_back(pair);
                                state = lineStart;
                        }
                        break;
@@ -1227,69 +1301,44 @@ void Options::setMacOSXVersionMin(const char* version)
                throw "-macosx_version_min argument missing";
 
        if ( (strncmp(version, "10.", 3) == 0) && isdigit(version[3]) ) {
-               int num = version[3] - '0';
-               switch ( num ) {
-                       case 0:
-                       case 1:
-                               fReaderOptions.fMacVersionMin = ObjectFile::ReaderOptions::k10_1;
-                               break;
-                       case 2:
-                               fReaderOptions.fMacVersionMin = ObjectFile::ReaderOptions::k10_2;
-                               break;
-                       case 3:
-                               fReaderOptions.fMacVersionMin = ObjectFile::ReaderOptions::k10_3;
-                               break;
-                       case 4:
-                               fReaderOptions.fMacVersionMin = ObjectFile::ReaderOptions::k10_4;
-                               break;
-                       case 5:
-                               fReaderOptions.fMacVersionMin = ObjectFile::ReaderOptions::k10_5;
-                               break;
-                       case 6:
-                               fReaderOptions.fMacVersionMin = ObjectFile::ReaderOptions::k10_6;
-                               break;
-                       default:
-                               fReaderOptions.fMacVersionMin = ObjectFile::ReaderOptions::k10_6;
-                               break;
-                       }
+               unsigned int minorVersion = 0;
+               for (int i=3; isdigit(version[i]); ++i) {
+                       minorVersion = minorVersion*10 + (version[i] - '0');
+               }
+               if ( minorVersion > 255 ) {
+                       warning("Mac OS X minor version > 255 in '%s'", version);
+                       minorVersion = 255;
+               }
+               fMacVersionMin = (ld::MacVersionMin)(0x000A0000 | (minorVersion << 8));
        }
        else {
                warning("unknown option to -macosx_version_min, not 10.x");
        }
 }
 
-void Options::setIPhoneVersionMin(const char* version)
+void Options::setIOSVersionMin(const char* version)
 {
        if ( version == NULL )
-               throw "-iphoneos_version_min argument missing";
+               throw "-ios_version_min argument missing";
        if ( ! isdigit(version[0]) )
-               throw "-iphoneos_version_min argument is not a number";
+               throw "-ios_version_min argument is not a number";
        if ( version[1] != '.' )
-               throw "-iphoneos_version_min argument is missing period as second character";
+               throw "-ios_version_min argument is missing period as second character";
        if ( ! isdigit(version[2]) )
-               throw "-iphoneos_version_min argument is not a number";
-
-       if ( version[0] == '2' )
-               fReaderOptions.fIPhoneVersionMin = ObjectFile::ReaderOptions::k2_0;
-       else if ( (version[0] == '3') && (version[2] == '0') )
-               fReaderOptions.fIPhoneVersionMin = ObjectFile::ReaderOptions::k2_0;
-       else if ( (version[0] == '3') && (version[2] >= '1') )
-               fReaderOptions.fIPhoneVersionMin = ObjectFile::ReaderOptions::k3_1;
-       else if ( (version[0] >= '4')  )
-               fReaderOptions.fIPhoneVersionMin = ObjectFile::ReaderOptions::k3_1;
-       else {
-               fReaderOptions.fIPhoneVersionMin = ObjectFile::ReaderOptions::k2_0;
-               warning("unknown option to -iphoneos_version_min, not 2.x, 3.x, or 4.x");
-       }
+               throw "-ios_version_min argument is not a number";
+
+       unsigned int majorVersion = version[0] - '0';
+       unsigned int minorVersion = version[2] - '0';
+       fIOSVersionMin = (ld::IOSVersionMin)((majorVersion << 16) | (minorVersion << 8));
 }
 
-bool Options::minOS(ObjectFile::ReaderOptions::MacVersionMin requiredMacMin, ObjectFile::ReaderOptions::IPhoneVersionMin requirediPhoneOSMin)
+bool Options::minOS(ld::MacVersionMin requiredMacMin, ld::IOSVersionMin requirediPhoneOSMin)
 {
-       if ( fReaderOptions.fMacVersionMin != ObjectFile::ReaderOptions::kMinMacVersionUnset ) {
-               return ( fReaderOptions.fMacVersionMin >= requiredMacMin );
+       if ( fMacVersionMin != ld::macVersionUnset ) {
+               return ( fMacVersionMin >= requiredMacMin );
        }
        else {
-               return ( fReaderOptions.fIPhoneVersionMin >= requirediPhoneOSMin);
+               return ( fIOSVersionMin >= requirediPhoneOSMin);
        }
 }
 
@@ -1372,16 +1421,67 @@ uint32_t Options::parseProtection(const char* prot)
 }
 
 
+//
+// Parses number of form A[.B[.B[.D[.E]]]] into a uint64_t where the bits are a24.b10.c10.d10.e10
+//
+uint64_t Options::parseVersionNumber64(const char* versionString)
+{
+       uint64_t a = 0;
+       uint64_t b = 0;
+       uint64_t c = 0;
+       uint64_t d = 0;
+       uint64_t e = 0;
+       char* end;
+       a = strtoul(versionString, &end, 10);
+       if ( *end == '.' ) {
+               b = strtoul(&end[1], &end, 10);
+               if ( *end == '.' ) {
+                       c = strtoul(&end[1], &end, 10);
+                       if ( *end == '.' ) {
+                               d = strtoul(&end[1], &end, 10);
+                               if ( *end == '.' ) {
+                                       e = strtoul(&end[1], &end, 10);
+                               }
+                       }
+               }
+       }
+       if ( (*end != '\0') || (a > 0xFFFFFF) || (b > 0x3FF) || (c > 0x3FF) || (d > 0x3FF)  || (e > 0x3FF) )
+               throwf("malformed 64-bit a.b.c.d.e version number: %s", versionString);
+
+       return (a << 40) | ( b << 30 ) | ( c << 20 ) | ( d << 10 ) | e;
+}
+
+
+uint32_t Options::currentVersion32() const
+{
+       // warn if it does not fit into 32 bit vers number
+       uint32_t a = (fDylibCurrentVersion >> 40) & 0xFFFF;
+       uint32_t b = (fDylibCurrentVersion >> 30) & 0xFF;
+       uint32_t c = (fDylibCurrentVersion >> 20) & 0xFF;
+       uint64_t rep32 = ((uint64_t)a << 40) |  ((uint64_t)b << 30) | ((uint64_t)c << 20);
+       if ( rep32 != fDylibCurrentVersion ) {
+               warning("truncating -current_version to fit in 32-bit space used by old mach-o format");
+               a = (fDylibCurrentVersion >> 40) & 0xFFFFFF;            
+               if ( a > 0xFFFF )
+                       a = 0xFFFF;
+               b = (fDylibCurrentVersion >> 30) & 0x3FF;
+               if ( b > 0xFF )
+                       b = 0xFF;
+               c = (fDylibCurrentVersion >> 20) & 0x3FF;
+               if ( c > 0xFF )
+                       c = 0xFF;
+       }
+       return (a << 16) | ( b << 8 ) | c;
+}
 
 //
 // Parses number of form X[.Y[.Z]] into a uint32_t where the nibbles are xxxx.yy.zz
 //
-//
-uint32_t Options::parseVersionNumber(const char* versionString)
+uint32_t Options::parseVersionNumber32(const char* versionString)
 {
-       unsigned long x = 0;
-       unsigned long y = 0;
-       unsigned long z = 0;
+       uint32_t x = 0;
+       uint32_t y = 0;
+       uint32_t z = 0;
        char* end;
        x = strtoul(versionString, &end, 10);
        if ( *end == '.' ) {
@@ -1391,7 +1491,7 @@ uint32_t Options::parseVersionNumber(const char* versionString)
                }
        }
        if ( (*end != '\0') || (x > 0xffff) || (y > 0xff) || (z > 0xff) )
-               throwf("malformed version number: %s", versionString);
+               throwf("malformed 32-bit x.y.z version number: %s", versionString);
 
        return (x << 16) | ( y << 8 ) | z;
 }
@@ -1478,7 +1578,7 @@ static const char* cstringSymbolName(const char* orderFileString)
 void Options::parseOrderFile(const char* path, bool cstring)
 {
        // order files override auto-ordering
-       fReaderOptions.fAutoOrderInitializers = false;
+       fAutoOrderInitializers = false;
 
        // read in whole file
        int fd = ::open(path, O_RDONLY, 0);
@@ -1493,6 +1593,8 @@ void Options::parseOrderFile(const char* path, bool cstring)
                throwf("can't read order file: %s", path);
        ::close(fd);
        p[stat_buf.st_size] = '\n';
+       if ( this->dumpDependencyInfo() )
+               this->dumpDependency(Options::depMisc, path);
 
        // parse into vector of pairs
        char * const end = &p[stat_buf.st_size+1];
@@ -1519,18 +1621,12 @@ void Options::parseOrderFile(const char* path, bool cstring)
                                        *last = '\0';
                                        --last;
                                }
+                               // if there is an architecture prefix, only use this symbol it if matches current arch
                                if ( strncmp(symbolStart, "ppc:", 4) == 0 ) {
-                                       if ( fArchitecture == CPU_TYPE_POWERPC )
-                                               symbolStart = &symbolStart[4];
-                                       else
-                                               symbolStart = NULL;
+                                       symbolStart = NULL;
                                }
-                               // if there is an architecture prefix, only use this symbol it if matches current arch
                                else if ( strncmp(symbolStart, "ppc64:", 6) == 0 ) {
-                                       if ( fArchitecture == CPU_TYPE_POWERPC64 )
-                                               symbolStart = &symbolStart[6];
-                                       else
-                                               symbolStart = NULL;
+                                       symbolStart = NULL;
                                }
                                else if ( strncmp(symbolStart, "i386:", 5) == 0 ) {
                                        if ( fArchitecture == CPU_TYPE_I386 )
@@ -1558,6 +1654,14 @@ void Options::parseOrderFile(const char* path, bool cstring)
                                                objFileName = symbolStart;
                                                symbolStart = &colon[3];
                                        }
+                                       else {
+                                               colon = strstr(symbolStart, ".o):");
+                                               if ( colon != NULL ) {
+                                                       colon[3] = '\0';
+                                                       objFileName = symbolStart;
+                                                       symbolStart = &colon[4];
+                                               }
+                                       }
                                        // trim leading spaces
                                        while ( isspace(*symbolStart) ) 
                                                ++symbolStart;
@@ -1628,6 +1732,27 @@ void Options::addSection(const char* segment, const char* section, const char* p
        fExtraSections.push_back(info);
 }
 
+void Options::addSectionRename(const char* srcSegment, const char* srcSection, const char* dstSegment, const char* dstSection)
+{
+       if ( strlen(srcSegment) > 16 )
+               throw "-rename_section segment name max 16 chars";
+       if ( strlen(srcSection) > 16 )
+               throw "-rename_section section name max 16 chars";
+       if ( strlen(dstSegment) > 16 )
+               throw "-rename_section segment name max 16 chars";
+       if ( strlen(dstSection) > 16 )
+               throw "-rename_section section name max 16 chars";
+
+       SectionRename info;
+       info.fromSegment = srcSegment;
+       info.fromSection = srcSection;
+       info.toSegment = dstSegment;
+       info.toSection = dstSection;
+
+       fSectionRenames.push_back(info);
+}
+
+
 void Options::addSectionAlignment(const char* segment, const char* section, const char* alignmentStr)
 {
        if ( strlen(segment) > 16 )
@@ -1694,6 +1819,9 @@ void Options::warnObsolete(const char* arg)
 //
 void Options::parse(int argc, const char* argv[])
 {
+    // Store the original args in the link snapshot.
+    fLinkSnapshot.recordRawArgs(argc, argv);
+    
        // pass one builds search list from -L and -F options
        this->buildSearchPaths(argc, argv);
 
@@ -1705,12 +1833,19 @@ void Options::parse(int argc, const char* argv[])
                const char* arg = argv[i];
 
                if ( arg[0] == '-' ) {
+            // by default, copy one arg to the snapshot link command, and do no file copying
+            int snapshotArgIndex = i;
+            int snapshotArgCount = -1; // -1 means compute count based on change in index
+            int snapshotFileArgIndex = -1; // -1 means no data file parameter to arg
 
                        // Since we don't care about the files passed, just the option names, we do this here.
                        if (fPrintOptions)
                                fprintf (stderr, "[Logging ld64 options]\t%s\n", arg);
 
                        if ( (arg[1] == 'L') || (arg[1] == 'F') ) {
+                snapshotArgCount = 0; // stripped out of link snapshot
+                               if (arg[2] == '\0')
+                                       ++i;
                                // previously handled by buildSearchPaths()
                        }
                        // The one gnu style option we have to keep compatibility
@@ -1727,8 +1862,8 @@ void Options::parse(int argc, const char* argv[])
                                // default
                        }
                        else if ( strcmp(arg, "-static") == 0 ) {
-                               fReaderOptions.fForStatic = true;
-                               if ( fOutputKind != kObjectFile ) {
+                               fForStatic = true;
+                               if ( (fOutputKind != kObjectFile) && (fOutputKind != kKextBundle) ) {
                                        fOutputKind = kStaticExecutable;
                                }
                        }
@@ -1755,26 +1890,41 @@ void Options::parse(int argc, const char* argv[])
                                fOutputKind = kKextBundle;
                        }
                        else if ( strcmp(arg, "-o") == 0 ) {
+                snapshotArgCount = 0;
                                fOutputFile = argv[++i];
-                       }
-                       else if ( (arg[1] == 'l') && (strncmp(arg,"-lazy_",6) !=0) ) {
-                               addLibrary(findLibrary(&arg[2]));
-                       }
-                       // This causes a dylib to be weakly bound at
-                       // link time.  This corresponds to weak_import.
-                       else if ( strncmp(arg, "-weak-l", 7) == 0 ) {
-                               FileInfo info = findLibrary(&arg[7]);
-                               info.options.fWeakImport = true;
-                               addLibrary(info);
+                fLinkSnapshot.setSnapshotName(fOutputFile);
                        }
                        else if ( strncmp(arg, "-lazy-l", 7) == 0 ) {
+                snapshotArgCount = 0;
                                FileInfo info = findLibrary(&arg[7], true);
                                info.options.fLazyLoad = true;
+                               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
                                addLibrary(info);
                                fUsingLazyDylibLinking = true;
                        }
+                       else if ( strcmp(arg, "-lto_library") == 0 ) {
+                snapshotFileArgIndex = 1;
+                               fOverridePathlibLTO = argv[++i];
+                               if ( fOverridePathlibLTO == NULL )
+                                       throw "missing argument to -lto_library";
+                       }
+                       else if ( (arg[1] == 'l') && (strncmp(arg,"-lazy_",6) !=0) ) {
+                snapshotArgCount = 0;
+                               FileInfo info = findLibrary(&arg[2]);
+                               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
+                               addLibrary(info);
+                       }
+                       // This causes a dylib to be weakly bound at
+                       // link time.  This corresponds to weak_import.
+                       else if ( strncmp(arg, "-weak-l", 7) == 0 ) {
+                // SNAPSHOT FIXME: what should we do for link snapshots? (ignore for now)
+                snapshotArgCount = 0;
+                               FileInfo info = findLibrary(&arg[7]);
+                               info.options.fWeakImport = true;
+                               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
+                               addLibrary(info);
+                       }
                        // Avoid lazy binding.
-                       // ??? Deprecate.
                        else if ( strcmp(arg, "-bind_at_load") == 0 ) {
                                fBindAtLoad = true;
                        }
@@ -1792,19 +1942,20 @@ void Options::parse(int argc, const char* argv[])
                        }
                        // Similar to --whole-archive.
                        else if ( strcmp(arg, "-all_load") == 0 ) {
-                               fReaderOptions.fFullyLoadArchives = true;
+                               fFullyLoadArchives = true;
                        }
                        else if ( strcmp(arg, "-noall_load") == 0) {
                                warnObsolete(arg);
                        }
                        // Similar to -all_load
                        else if ( strcmp(arg, "-ObjC") == 0 ) {
-                               fReaderOptions.fLoadAllObjcObjectsFromArchives = true;
+                               fLoadAllObjcObjectsFromArchives = true;
                        }
                        // Similar to -all_load, but for the following archive only.
                        else if ( strcmp(arg, "-force_load") == 0 ) {
                                FileInfo info = findFile(argv[++i]);
                                info.options.fForceLoad = true;
+                               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
                                addLibrary(info);
                        }
                        // Library versioning.
@@ -1813,22 +1964,24 @@ void Options::parse(int argc, const char* argv[])
                                 const char* vers = argv[++i];
                                 if ( vers == NULL )
                                        throw "-dylib_compatibility_version missing <version>";
-                               fDylibCompatVersion = parseVersionNumber(vers);
+                               fDylibCompatVersion = parseVersionNumber32(vers);
                        }
                        else if ( (strcmp(arg, "-dylib_current_version") == 0)
                                          || (strcmp(arg, "-current_version") == 0)) {
                                 const char* vers = argv[++i];
                                 if ( vers == NULL )
                                        throw "-dylib_current_version missing <version>";
-                               fDylibCurrentVersion = parseVersionNumber(vers);
+                               fDylibCurrentVersion = parseVersionNumber64(vers);
                        }
                        else if ( strcmp(arg, "-sectorder") == 0 ) {
                                 if ( (argv[i+1]==NULL) || (argv[i+2]==NULL) || (argv[i+3]==NULL) )
                                        throw "-sectorder missing <segment> <section> <file-path>";
+                snapshotFileArgIndex = 3;
                                parseSectionOrderFile(argv[i+1], argv[i+2], argv[i+3]);
                                i += 3;
                        }
                        else if ( strcmp(arg, "-order_file") == 0 ) {
+                snapshotFileArgIndex = 1;
                                parseOrderFile(argv[++i], false);
                        }
                        else if ( strcmp(arg, "-order_file_statistics") == 0 ) {
@@ -1839,6 +1992,7 @@ void Options::parse(int argc, const char* argv[])
                        else if ( (strcmp(arg, "-sectcreate") == 0) || (strcmp(arg, "-segcreate") == 0) ) {
                                 if ( (argv[i+1]==NULL) || (argv[i+2]==NULL) || (argv[i+3]==NULL) )
                                        throw "-sectcreate missing <segment> <section> <file-path>";
+                snapshotFileArgIndex = 3;
                                addSection(argv[i+1], argv[i+2], argv[i+3]);
                                i += 3;
                        }
@@ -1847,7 +2001,7 @@ void Options::parse(int argc, const char* argv[])
                                          || (strcmp(arg, "-dylinker_install_name") == 0)
                                          || (strcmp(arg, "-install_name") == 0)) {
                                fDylibInstallName = argv[++i];
-                                if ( fDylibInstallName == NULL )
+                if ( fDylibInstallName == NULL )
                                        throw "-install_name missing <path>";
                        }
                        // Sets the base address of the output.
@@ -1867,10 +2021,12 @@ void Options::parse(int argc, const char* argv[])
                        }
                        // Same as -@ from the FSF linker.
                        else if ( strcmp(arg, "-filelist") == 0 ) {
+                 snapshotArgCount = 0;
                                 const char* path = argv[++i];
                                 if ( (path == NULL) || (path[0] == '-') )
                                        throw "-filelist missing <path>";
-                                loadFileList(path);
+                                ld::File::Ordinal baseOrdinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
+                                loadFileList(path, baseOrdinal);
                        }
                        else if ( strcmp(arg, "-keep_private_externs") == 0 ) {
                                 fKeepPrivateExterns = true;
@@ -1892,6 +2048,7 @@ void Options::parse(int argc, const char* argv[])
                                }
                        }
                        else if ( strcmp(arg, "-interposable_list") == 0 ) {
+                snapshotFileArgIndex = 1;
                                fInterposeMode = kInterposeSome;
                                loadExportFile(argv[++i], "-interposable_list", fInterposeList);
                        }
@@ -1900,12 +2057,14 @@ void Options::parse(int argc, const char* argv[])
                                fInterposeMode = kInterposeNone;
                        }
                        else if ( strcmp(arg, "-exported_symbols_list") == 0 ) {
+                snapshotFileArgIndex = 1;
                                if ( fExportMode == kDontExportSome )
                                        throw "can't use -exported_symbols_list and -unexported_symbols_list";
                                fExportMode = kExportSome;
                                loadExportFile(argv[++i], "-exported_symbols_list", fExportSymbols);
                        }
                        else if ( strcmp(arg, "-unexported_symbols_list") == 0 ) {
+                snapshotFileArgIndex = 1;
                                if ( fExportMode == kExportSome )
                                        throw "can't use -unexported_symbols_list and -exported_symbols_list";
                                fExportMode = kDontExportSome;
@@ -1924,12 +2083,14 @@ void Options::parse(int argc, const char* argv[])
                                fDontExportSymbols.insert(argv[++i]);
                        }
                        else if ( strcmp(arg, "-non_global_symbols_no_strip_list") == 0 ) {
+                snapshotFileArgIndex = 1;
                                if ( fLocalSymbolHandling == kLocalSymbolsSelectiveExclude )
                                        throw "can't use -non_global_symbols_no_strip_list and -non_global_symbols_strip_list";
                                fLocalSymbolHandling = kLocalSymbolsSelectiveInclude;
                                loadExportFile(argv[++i], "-non_global_symbols_no_strip_list", fLocalSymbolsIncluded);
                        }
                        else if ( strcmp(arg, "-non_global_symbols_strip_list") == 0 ) {
+                snapshotFileArgIndex = 1;
                                if ( fLocalSymbolHandling == kLocalSymbolsSelectiveInclude )
                                        throw "can't use -non_global_symbols_no_strip_list and -non_global_symbols_strip_list";
                                fLocalSymbolHandling = kLocalSymbolsSelectiveExclude;
@@ -1940,39 +2101,58 @@ void Options::parse(int argc, const char* argv[])
                                 fIgnoreOtherArchFiles = true;
                        }
                        else if ( strcmp(arg, "-force_cpusubtype_ALL") == 0 ) {
-                                fForceSubtypeAll = true;
+                               fForceSubtypeAll = true;
+                               fAllowCpuSubtypeMismatches = true;
                        }
                        // Similar to -weak-l but uses the absolute path name to the library.
                        else if ( strcmp(arg, "-weak_library") == 0 ) {
+                // SNAPSHOT FIXME: what should we do for link snapshots? (ignore for now)
+                snapshotArgCount = 0;
                                FileInfo info = findFile(argv[++i]);
                                info.options.fWeakImport = true;
+                               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
                                addLibrary(info);
                        }
                        else if ( strcmp(arg, "-lazy_library") == 0 ) {
+                // SNAPSHOT FIXME: what should we do for link snapshots? (ignore for now)
+                snapshotArgCount = 0;
                                FileInfo info = findFile(argv[++i]);
                                info.options.fLazyLoad = true;
+                               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
                                addLibrary(info);
                                fUsingLazyDylibLinking = true;
                        }
                        else if ( strcmp(arg, "-framework") == 0 ) {
-                               addLibrary(findFramework(argv[++i]));
+                snapshotArgCount = 0;
+                               FileInfo info = findFramework(argv[++i]);
+                               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
+                               addLibrary(info);
                        }
                        else if ( strcmp(arg, "-weak_framework") == 0 ) {
+                // SNAPSHOT FIXME: what should we do for link snapshots? (ignore for now)
+                snapshotArgCount = 0;
                                FileInfo info = findFramework(argv[++i]);
                                info.options.fWeakImport = true;
+                               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
                                addLibrary(info);
                        }
                        else if ( strcmp(arg, "-lazy_framework") == 0 ) {
+                // SNAPSHOT FIXME: what should we do for link snapshots? (ignore for now)
+                snapshotArgCount = 0;
                                FileInfo info = findFramework(argv[++i]);
                                info.options.fLazyLoad = true;
+                               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
                                addLibrary(info);
                                fUsingLazyDylibLinking = true;
                        }
                        else if ( strcmp(arg, "-search_paths_first") == 0 ) {
                                // previously handled by buildSearchPaths()
                        }
+                       else if ( strcmp(arg, "-search_dylibs_first") == 0 ) {
+                               // previously handled by buildSearchPaths()
+                       }
                        else if ( strcmp(arg, "-undefined") == 0 ) {
-                                setUndefinedTreatment(argv[++i]);
+                setUndefinedTreatment(argv[++i]);
                        }
                        // Debugging output flag.
                        else if ( strcmp(arg, "-arch_multiple") == 0 ) {
@@ -2008,7 +2188,7 @@ void Options::parse(int argc, const char* argv[])
                        // Warn, error or make strong a mismatch between weak
                        // and non-weak references.
                        else if ( strcmp(arg, "-weak_reference_mismatches") == 0 ) {
-                                setWeakReferenceMismatchTreatment(argv[++i]);
+                setWeakReferenceMismatchTreatment(argv[++i]);
                        }
                        // For a deployment target of 10.3 and earlier ld64 will
                        // prebind an executable with 0s in all addresses that
@@ -2036,6 +2216,8 @@ void Options::parse(int argc, const char* argv[])
                        // This should probably be deprecated when we respect -L and -F
                        // when searching for libraries.
                        else if ( strcmp(arg, "-dylib_file") == 0 ) {
+                // ignore for snapshot because a stub dylib will be created in the snapshot
+                 snapshotArgCount = 0;
                                 addDylibOverride(argv[++i]);
                        }
                        // What to expand @executable_path to if found in dependent dylibs
@@ -2076,9 +2258,9 @@ void Options::parse(int argc, const char* argv[])
                                 if ( (seg.name == NULL) || (argv[i+1] == NULL) )
                                        throw "-segaddr missing segName Adddress";
                                seg.address = parseAddress(argv[++i]);
-                               uint64_t temp = seg.address & (-4096); // page align
-                               if ( (seg.address != temp)  )
-                                       warning("-segaddr %s not page aligned, rounding down", seg.name);
+                               uint64_t temp = ((seg.address+fSegmentAlignment-1) & (-fSegmentAlignment)); 
+                               if ( seg.address != temp )
+                                       warning("-segaddr %s not %lld byte aligned", seg.name, fSegmentAlignment);
                                fCustomSegmentAddresses.push_back(seg);
                        }
                        // ??? Deprecate when we deprecate split-seg.
@@ -2092,6 +2274,7 @@ void Options::parse(int argc, const char* argv[])
                        }
                        // ??? Deprecate when we get rid of basing at build time.
                        else if ( strcmp(arg, "-seg_addr_table") == 0 ) {
+                snapshotFileArgIndex = 1;
                                const char* name = argv[++i];
                                if ( name == NULL )
                                        throw "-seg_addr_table missing argument";
@@ -2138,6 +2321,9 @@ void Options::parse(int argc, const char* argv[])
                        else if ( strcmp(arg, "-allow_stack_execute") == 0 ) {
                                fExecutableStack = true;
                        }
+                       else if ( strcmp(arg, "-allow_heap_execute") == 0 ) {
+                               fDisableNonExecutableHeap = true;
+                       }
                        else if ( strcmp(arg, "-sectalign") == 0 ) {
                                 if ( (argv[i+1]==NULL) || (argv[i+2]==NULL) || (argv[i+3]==NULL) )
                                        throw "-sectalign missing <segment> <section> <file-path>";
@@ -2152,10 +2338,12 @@ void Options::parse(int argc, const char* argv[])
                                i += 2;
                        }
                        else if ( strcmp(arg, "-bundle_loader") == 0 ) {
+                snapshotFileArgIndex = 1;
                                fBundleLoader = argv[++i];
                                if ( (fBundleLoader == NULL) || (fBundleLoader[0] == '-') )
                                        throw "-bundle_loader missing <path>";
                                FileInfo info = findFile(fBundleLoader);
+                               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
                                info.options.fBundleLoader = true;
                                fInputFiles.push_back(info);
                        }
@@ -2167,10 +2355,34 @@ void Options::parse(int argc, const char* argv[])
                        }
                        // Use this flag to set default behavior for deployement targets.
                        else if ( strcmp(arg, "-macosx_version_min") == 0 ) {
-                               setMacOSXVersionMin(argv[++i]);
+                               const char* macVers = argv[++i];
+                               const char* envMacVers = getenv("MACOSX_DEPLOYMENT_TARGET");
+                               const char* enviPhoneVers = getenv("IPHONEOS_DEPLOYMENT_TARGET");
+                               if ( (envMacVers != NULL) && (enviPhoneVers != NULL) ) {
+                                       // <rdar://problem/13774329> when conflicting deployments set, break tie by looking at syslibroot
+                                       warning("both MACOSX_DEPLOYMENT_TARGET and IPHONEOS_DEPLOYMENT_TARGET are set");
+                                       if ( !fSDKPaths.empty() ) {
+                                               const char* sysrootPath = fSDKPaths.back();
+                                               const char* lastSlash = strrchr(sysrootPath, '/');
+                                               if ( strstr(lastSlash, "Simulator") != NULL ) 
+                                                       setIOSVersionMin(enviPhoneVers);
+                                               else
+                                                       setMacOSXVersionMin(macVers);
+                                       }
+                                       else {
+                                               setMacOSXVersionMin(macVers);
+                                       }
+                               }
+                               else {
+                                       setMacOSXVersionMin(macVers);
+                               }
                        }
-                       else if ( strcmp(arg, "-iphoneos_version_min") == 0 ) {
-                               setIPhoneVersionMin(argv[++i]);
+                       else if ( (strcmp(arg, "-ios_version_min") == 0) || (strcmp(arg, "-iphoneos_version_min") == 0) ) {
+                               setIOSVersionMin(argv[++i]); 
+                       }
+                       else if ( strcmp(arg, "-ios_simulator_version_min") == 0 ) {
+                               setIOSVersionMin(argv[++i]);
+                               fTargetIOSSimulator = true;
                        }
                        else if ( strcmp(arg, "-multiply_defined") == 0 ) {
                                //warnObsolete(arg);
@@ -2199,7 +2411,7 @@ void Options::parse(int argc, const char* argv[])
                                warnObsolete(arg);
                        }
                        else if ( (strcmp(arg, "-why_load") == 0) || (strcmp(arg, "-whyload") == 0) ) {
-                                fReaderOptions.fWhyLoad = true;
+                                fWhyLoad = true;
                        }
                        else if ( strcmp(arg, "-why_live") == 0 ) {
                                 const char* name = argv[++i];
@@ -2222,40 +2434,43 @@ void Options::parse(int argc, const char* argv[])
                        else if ( strcmp(arg, "-s") == 0 ) {
                                warnObsolete(arg);
                                fLocalSymbolHandling = kLocalSymbolsNone;
-                               fReaderOptions.fDebugInfoStripping = ObjectFile::ReaderOptions::kDebugInfoNone;
+                               fDebugInfoStripping = Options::kDebugInfoNone;
                        }
                        else if ( strcmp(arg, "-x") == 0 ) {
                                fLocalSymbolHandling = kLocalSymbolsNone;
                        }
                        else if ( strcmp(arg, "-S") == 0 ) {
-                               fReaderOptions.fDebugInfoStripping = ObjectFile::ReaderOptions::kDebugInfoNone;
+                               fDebugInfoStripping = Options::kDebugInfoNone;
                        }
                        else if ( strcmp(arg, "-X") == 0 ) {
                                warnObsolete(arg);
                        }
                        else if ( strcmp(arg, "-Si") == 0 ) {
                                warnObsolete(arg);
-                               fReaderOptions.fDebugInfoStripping = ObjectFile::ReaderOptions::kDebugInfoFull;
+                               fDebugInfoStripping = Options::kDebugInfoFull;
                        }
                        else if ( strcmp(arg, "-b") == 0 ) {
                                warnObsolete(arg);
                        }
                        else if ( strcmp(arg, "-Sn") == 0 ) {
                                warnObsolete(arg);
-                               fReaderOptions.fDebugInfoStripping = ObjectFile::ReaderOptions::kDebugInfoFull;
+                               fDebugInfoStripping = Options::kDebugInfoFull;
                        }
                        else if ( strcmp(arg, "-Sp") == 0 ) {
                                warnObsolete(arg);
                        }
                        else if ( strcmp(arg, "-dead_strip") == 0 ) {
-                               fDeadStrip = kDeadStripOnPlusUnusedInits;
+                               fDeadStrip = true;
                        }
                        else if ( strcmp(arg, "-no_dead_strip_inits_and_terms") == 0 ) {
-                               fDeadStrip = kDeadStripOn;
+                               fDeadStrip = true;
                        }
                        else if ( strcmp(arg, "-w") == 0 ) {
                                // previously handled by buildSearchPaths()
                        }
+                       else if ( strcmp(arg, "-fatal_warnings") == 0 ) {
+                               // previously handled by buildSearchPaths()
+                       }
                        else if ( strcmp(arg, "-arch_errors_fatal") == 0 ) {
                                fErrorOnOtherArchFiles = true;
                        }
@@ -2272,10 +2487,10 @@ void Options::parse(int argc, const char* argv[])
                                fMaxMinimumHeaderPad = true;
                        }
                        else if ( strcmp(arg, "-t") == 0 ) {
-                               fReaderOptions.fLogAllFiles = true;
+                               fLogAllFiles = true;
                        }
                        else if ( strcmp(arg, "-whatsloaded") == 0 ) {
-                               fReaderOptions.fLogObjectFiles = true;
+                               fLogObjectFiles = true;
                        }
                        else if ( strcmp(arg, "-A") == 0 ) {
                                warnObsolete(arg);
@@ -2346,7 +2561,7 @@ void Options::parse(int argc, const char* argv[])
                                fStatistics = true;
                        }
                        else if ( strcmp(arg, "-d") == 0 ) {
-                               fReaderOptions.fMakeTentativeDefinitionsReal = true;
+                               fMakeTentativeDefinitionsReal = true;
                        }
                        else if ( strcmp(arg, "-v") == 0 ) {
                                // previously handled by buildSearchPaths()
@@ -2355,6 +2570,7 @@ void Options::parse(int argc, const char* argv[])
                                // previously handled by buildSearchPaths()
                        }
                        else if ( strcmp(arg, "-syslibroot") == 0 ) {
+                snapshotArgCount = 0;
                                ++i;
                                // previously handled by buildSearchPaths()
                        }
@@ -2365,42 +2581,32 @@ void Options::parse(int argc, const char* argv[])
                                fUUIDMode = kUUIDRandom;
                        }
                        else if ( strcmp(arg, "-dtrace") == 0 ) {
+                snapshotFileArgIndex = 1;
                                const char* name = argv[++i];
                                if ( name == NULL )
                                        throw "-dtrace missing argument";
                                fDtraceScriptName = name;
                        }
                        else if ( strcmp(arg, "-root_safe") == 0 ) {
-                               fReaderOptions.fRootSafe = true;
+                               fRootSafe = true;
                        }
                        else if ( strcmp(arg, "-setuid_safe") == 0 ) {
-                               fReaderOptions.fSetuidSafe = true;
+                               fSetuidSafe = true;
                        }
                        else if ( strcmp(arg, "-alias") == 0 ) {
-                               ObjectFile::ReaderOptions::AliasPair pair;
+                               Options::AliasPair pair;
                                pair.realName = argv[++i];
                                if ( pair.realName == NULL )
                                        throw "missing argument to -alias";
                                pair.alias = argv[++i];
                                if ( pair.alias == NULL )
                                        throw "missing argument to -alias";
-                               fReaderOptions.fAliases.push_back(pair);
+                               fAliases.push_back(pair);
                        }
                        else if ( strcmp(arg, "-alias_list") == 0 ) {
+                snapshotFileArgIndex = 1;
                                parseAliasFile(argv[++i]);
                        }
-                       // put this last so that it does not interfer with other options starting with 'i'
-                       else if ( strncmp(arg, "-i", 2) == 0 ) {
-                               const char* colon = strchr(arg, ':');
-                               if ( colon == NULL )
-                                       throwf("unknown option: %s", arg);
-                               ObjectFile::ReaderOptions::AliasPair pair;
-                               char* temp = new char[colon-arg];
-                               strlcpy(temp, &arg[2], colon-arg-1);
-                               pair.realName = &colon[1];
-                               pair.alias = temp;
-                               fReaderOptions.fAliases.push_back(pair);
-                       }
                        else if ( strcmp(arg, "-save-temps") == 0 ) {
                                fSaveTempFiles = true;
                        }
@@ -2423,27 +2629,64 @@ void Options::parse(int argc, const char* argv[])
                        }
                        else if ( strcmp(arg, "-pie") == 0 ) {
                                fPositionIndependentExecutable = true;
+                               fPIEOnCommandLine = true;
+                       }
+                       else if ( strcmp(arg, "-no_pie") == 0 ) {
+                               fDisablePositionIndependentExecutable = true;
                        }
                        else if ( strncmp(arg, "-reexport-l", 11) == 0 ) {
+                // SNAPSHOT FIXME: what should we do for link snapshots? (ignore for now)
+                snapshotArgCount = 0;
                                FileInfo info = findLibrary(&arg[11], true);
                                info.options.fReExport = true;
+                               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
                                addLibrary(info);
                        }
                        else if ( strcmp(arg, "-reexport_library") == 0 ) {
+                // SNAPSHOT FIXME: what should we do for link snapshots? (ignore for now)
+                snapshotArgCount = 0;
                                FileInfo info = findFile(argv[++i]);
                                info.options.fReExport = true;
+                               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
                                addLibrary(info);
                        }
                        else if ( strcmp(arg, "-reexport_framework") == 0 ) {
+                // SNAPSHOT FIXME: what should we do for link snapshots? (ignore for now)
+                snapshotArgCount = 0;
                                FileInfo info = findFramework(argv[++i]);
                                info.options.fReExport = true;
+                               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
+                               addLibrary(info);
+                       }
+                       else if ( strncmp(arg, "-upward-l", 9) == 0 ) {
+                // SNAPSHOT FIXME: what should we do for link snapshots? (ignore for now)
+                snapshotArgCount = 0;
+                               FileInfo info = findLibrary(&arg[9], true);
+                               info.options.fUpward = true;
+                               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
+                               addLibrary(info);
+                       }
+                       else if ( strcmp(arg, "-upward_library") == 0 ) {
+                // SNAPSHOT FIXME: what should we do for link snapshots? (ignore for now)
+                snapshotArgCount = 0;
+                               FileInfo info = findFile(argv[++i]);
+                               info.options.fUpward = true;
+                               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
+                               addLibrary(info);
+                       }
+                       else if ( strcmp(arg, "-upward_framework") == 0 ) {
+                // SNAPSHOT FIXME: what should we do for link snapshots? (ignore for now)
+                snapshotArgCount = 0;
+                               FileInfo info = findFramework(argv[++i]);
+                               info.options.fUpward = true;
+                               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
                                addLibrary(info);
                        }
                        else if ( strcmp(arg, "-dead_strip_dylibs") == 0 ) {
                                fDeadStripDylibs = true;
                        }
                        else if ( strcmp(arg, "-no_implicit_dylibs") == 0 ) {
-                               fReaderOptions.fImplicitlyLinkPublicDylibs = false;
+                               fImplicitlyLinkPublicDylibs = false;
                        }
                        else if ( strcmp(arg, "-new_linker") == 0 ) {
                                // ignore
@@ -2452,7 +2695,7 @@ void Options::parse(int argc, const char* argv[])
                                fEncryptable = false;
                        }
                        else if ( strcmp(arg, "-no_compact_unwind") == 0 ) {
-                               fReaderOptions.fAddCompactUnwindEncoding = false;
+                               fAddCompactUnwindEncoding = false;
                        }
                        else if ( strcmp(arg, "-mllvm") == 0 ) {
                                const char* opts = argv[++i];
@@ -2460,8 +2703,14 @@ void Options::parse(int argc, const char* argv[])
                                        throw "missing argument to -mllvm";
                                fLLVMOptions.push_back(opts);
                        }
+                       else if ( strcmp(arg, "-mcpu") == 0 ) {
+                               const char* cpu = argv[++i];
+                               if ( cpu == NULL )
+                                       throw "missing argument to -mcpu";
+                               fLtoCpu = cpu;
+                       }
                        else if ( strcmp(arg, "-no_order_inits") == 0 ) {
-                               fReaderOptions.fAutoOrderInitializers = false;
+                               fAutoOrderInitializers = false;
                        }
                        else if ( strcmp(arg, "-no_order_data") == 0 ) {
                                fOrderData = false;
@@ -2481,29 +2730,265 @@ void Options::parse(int argc, const char* argv[])
                                fMarkDeadStrippableDylib = true;
                        }
                        else if ( strcmp(arg, "-exported_symbols_order") == 0 ) {
+                snapshotFileArgIndex = 1;
                                loadSymbolOrderFile(argv[++i], fExportSymbolsOrder);
                        }
                        else if ( strcmp(arg, "-no_compact_linkedit") == 0 ) {
-                               fMakeCompressedDyldInfo = false;
+                               warnObsolete("-no_compact_linkedit");
                        }
                        else if ( strcmp(arg, "-no_eh_labels") == 0 ) {
-                               fReaderOptions.fNoEHLabels = true;
+                               fNoEHLabels = true;
                        }
                        else if ( strcmp(arg, "-warn_compact_unwind") == 0 ) {
-                               fReaderOptions.fWarnCompactUnwind = true;
+                               fWarnCompactUnwind = true;
                        }
                        else if ( strcmp(arg, "-allow_sub_type_mismatches") == 0 ) {
                                fAllowCpuSubtypeMismatches = true;
                        }
                        else if ( strcmp(arg, "-no_zero_fill_sections") == 0 ) {
-                               fReaderOptions.fOptimizeZeroFill = false;
+                               fOptimizeZeroFill = false;
+                       }
+                       else if ( strcmp(arg, "-merge_zero_fill_sections") == 0 ) {
+                               fMergeZeroFill = true;
+                       }
+                       else if ( strcmp(arg, "-objc_abi_version") == 0 ) {
+                               const char* version = argv[++i];
+                                if ( version == NULL )
+                                       throw "-objc_abi_version missing version number";
+                               if ( strcmp(version, "2") == 0 ) {
+                                       fObjCABIVersion1Override = false;
+                                       fObjCABIVersion2Override = true;
+                               }
+                               else if ( strcmp(version, "1") == 0 ) {
+                                       fObjCABIVersion1Override = true;
+                                       fObjCABIVersion2Override = false;
+                               }
+                               else
+                                       warning("ignoring unrecognized argument (%s) to -objc_abi_version", version);
+                       }
+                       else if ( strcmp(arg, "-warn_weak_exports") == 0 ) {
+                               fWarnWeakExports = true;
+                       }
+                       else if ( strcmp(arg, "-objc_gc_compaction") == 0 ) {
+                               fObjcGcCompaction = true;
+                       }
+                       else if ( strcmp(arg, "-objc_gc") == 0 ) {
+                               fObjCGc = true;
+                               if ( fObjCGcOnly ) { 
+                                       warning("-objc_gc overriding -objc_gc_only");
+                                       fObjCGcOnly = false;    
+                               }
+                       }
+                       else if ( strcmp(arg, "-objc_gc_only") == 0 ) {
+                               fObjCGcOnly = true;
+                               if ( fObjCGc ) { 
+                                       warning("-objc_gc_only overriding -objc_gc");
+                                       fObjCGc = false;        
+                               }
+                       }
+                       else if ( strcmp(arg, "-demangle") == 0 ) {
+                               fDemangle = true;
+                       }
+                       else if ( strcmp(arg, "-version_load_command") == 0 ) {
+                               fVersionLoadCommandForcedOn = true;
+                               fVersionLoadCommandForcedOff = false;
+                       }
+                       else if ( strcmp(arg, "-no_version_load_command") == 0 ) {
+                               fVersionLoadCommandForcedOff = true;
+                               fVersionLoadCommandForcedOn = false;
+                       }
+                       else if ( strcmp(arg, "-function_starts") == 0 ) {
+                               fFunctionStartsForcedOn = true;
+                               fFunctionStartsForcedOff = false;
+                       }
+                       else if ( strcmp(arg, "-no_function_starts") == 0 ) {
+                               fFunctionStartsForcedOff = true;
+                               fFunctionStartsForcedOn = false;
+                       }
+                       else if ( strcmp(arg, "-no_data_in_code_info") == 0 ) {
+                               fDataInCodeInfoLoadCommandForcedOff = true;
+                               fDataInCodeInfoLoadCommandForcedOn = false;
+                       }
+                       else if ( strcmp(arg, "-data_in_code_info") == 0 ) {
+                               fDataInCodeInfoLoadCommandForcedOn  = true;
+                               fDataInCodeInfoLoadCommandForcedOff = false;
+                       }
+                       else if ( strcmp(arg, "-object_path_lto") == 0 ) {
+                               fTempLtoObjectPath = argv[++i];
+                               if ( fTempLtoObjectPath == NULL )
+                                       throw "missing argument to -object_path_lto";
+                       }
+                       else if ( strcmp(arg, "-no_objc_category_merging") == 0 ) {
+                               fObjcCategoryMerging = false;
+                       }
+                       else if ( strcmp(arg, "-force_symbols_weak_list") == 0 ) {
+                snapshotFileArgIndex = 1;
+                               loadExportFile(argv[++i], "-force_symbols_weak_list", fForceWeakSymbols);
+                       }
+                       else if ( strcmp(arg, "-force_symbols_not_weak_list") == 0 ) {
+                snapshotFileArgIndex = 1;
+                               loadExportFile(argv[++i], "-force_symbols_not_weak_list", fForceNotWeakSymbols);
+                       }
+                       else if ( strcmp(arg, "-force_symbol_weak") == 0 ) {
+                               const char* symbol = argv[++i];
+                               if ( symbol == NULL )
+                                       throw "-force_symbol_weak missing <symbol>";
+                               fForceWeakSymbols.insert(symbol);
+                       }
+                       else if ( strcmp(arg, "-force_symbol_not_weak") == 0 ) {
+                               const char* symbol = argv[++i];
+                               if ( symbol == NULL )
+                                       throw "-force_symbol_not_weak missing <symbol>";
+                               fForceNotWeakSymbols.insert(symbol);
+                       }
+                       else if ( strcmp(arg, "-reexported_symbols_list") == 0 ) {
+                snapshotFileArgIndex = 1;
+                               if ( fExportMode == kExportSome )
+                                       throw "can't use -exported_symbols_list and -reexported_symbols_list";
+                               loadExportFile(argv[++i], "-reexported_symbols_list", fReExportSymbols);
+                       }
+                       else if ( strcmp(arg, "-dyld_env") == 0 ) {
+                               const char* envarg = argv[++i];
+                               if ( envarg == NULL )
+                                       throw "-dyld_env missing ENV=VALUE";
+                               if ( strchr(envarg, '=') == NULL )
+                                       throw "-dyld_env missing ENV=VALUE";
+                               fDyldEnvironExtras.push_back(envarg);
+                       }
+                       else if ( strcmp(arg, "-page_align_data_atoms") == 0 ) {
+                               fPageAlignDataAtoms = true;
+                       } 
+                       else if (strcmp(arg, "-debug_snapshot") == 0) {
+                fLinkSnapshot.setSnapshotMode(Snapshot::SNAPSHOT_DEBUG);
+                fSnapshotRequested = true;
+            }
+                       else if (strcmp(arg, "-snapshot_dir") == 0) {
+                               const char* path = argv[++i];
+                               if ( path == NULL )
+                                       throw "-snapshot_dir missing path";
+                               fLinkSnapshot.setSnapshotMode(Snapshot::SNAPSHOT_DEBUG);
+                               fLinkSnapshot.setSnapshotPath(path);
+                               fSnapshotRequested = true;
+            }
+                       else if ( strcmp(arg, "-new_main") == 0 ) {
+                               fEntryPointLoadCommandForceOn = true;
+                       }
+                       else if ( strcmp(arg, "-no_new_main") == 0 ) {
+                               fEntryPointLoadCommandForceOff = true;
+                       }
+                       else if ( strcmp(arg, "-source_version") == 0 ) {
+                                const char* vers = argv[++i];
+                                if ( vers == NULL )
+                                       throw "-source_version missing <version>";
+                               fSourceVersion = parseVersionNumber64(vers);
+                       }
+                       else if ( strcmp(arg, "-add_source_version") == 0 ) {
+                               fSourceVersionLoadCommandForceOn = true;
+                       }
+                       else if ( strcmp(arg, "-no_source_version") == 0 ) {
+                               fSourceVersionLoadCommandForceOff = true;
+                       }
+                       else if ( strcmp(arg, "-sdk_version") == 0 ) {
+                                const char* vers = argv[++i];
+                                if ( vers == NULL )
+                                       throw "-sdk_version missing <version>";
+                               fSDKVersion = parseVersionNumber32(vers);
+                       }
+                       else if ( strcmp(arg, "-dependent_dr_info") == 0 ) {
+                               fDependentDRInfoForcedOn = true;
+                       }
+                       else if ( strcmp(arg, "-no_dependent_dr_info") == 0 ) {
+                               fDependentDRInfoForcedOff = true;
+                       }
+                       else if ( strcmp(arg, "-kexts_use_stubs") == 0 ) {
+                               fKextsUseStubs = true;
+                       }
+                       else if ( strcmp(argv[i], "-dependency_info") == 0 ) {
+                               ++i;
+                               // previously handled by buildSearchPaths()
+                       }
+                       else if ( strcmp(arg, "-export_dynamic") == 0 ) {
+                               fExportDynamic = true;
+                       }
+                       else if ( strcmp(arg, "-force_symbols_coalesce_list") == 0 ) {
+                snapshotFileArgIndex = 1;
+                               loadExportFile(argv[++i], "-force_symbols_coalesce_list", fForceCoalesceSymbols);
+                       }
+                       else if ( strcmp(arg, "-add_linker_option") == 0 ) {
+                               // ex: -add_linker_option '-framework Foundation'
+                               const char* optString = argv[++i];
+                               if ( optString == NULL )
+                                       throw "-add_linker_option missing <option>";
+                               // break up into list of tokens at whitespace
+                               std::vector<const char*> opts;
+                               char* buffer = strdup(optString);
+                               char* start = buffer;
+                               for (char* s = buffer; ; ++s) {
+                                       if ( isspace(*s)  ) {
+                                               *s = '\0';
+                                               opts.push_back(start);
+                                               start = s+1;
+                                       }
+                                       else if ( *s == '\0' ) {
+                                               opts.push_back(start);
+                                               break;
+                                       }
+                               }
+                               fLinkerOptions.push_back(opts);
+                       }
+                       else if ( strcmp(arg, "-allow_simulator_linking_to_macosx_dylibs") == 0 ) {
+                               fAllowSimulatorToLinkWithMacOSX = true;
+                       }
+                       else if ( strcmp(arg, "-keep_dwarf_unwind") == 0 ) {
+                               fKeepDwarfUnwindForcedOn = true;
+                               fKeepDwarfUnwindForcedOff = false;
+                       }
+                       else if ( strcmp(arg, "-no_keep_dwarf_unwind") == 0 ) {
+                               fKeepDwarfUnwindForcedOn = false;
+                               fKeepDwarfUnwindForcedOff = true;
+                       }
+                       else if ( strcmp(arg, "-verbose_optimization_hints") == 0 ) {
+                               fVerboseOptimizationHints = true;
+                       }
+                       else if ( strcmp(arg, "-ignore_optimization_hints") == 0 ) {
+                               fIgnoreOptimizationHints = true;
+                       }
+                       else if ( strcmp(arg, "-no_dtrace_dof") == 0 ) {
+                               fGenerateDtraceDOF = false;
+                       }
+                       else if ( strcmp(arg, "-rename_section") == 0 ) {
+                                if ( (argv[i+1]==NULL) || (argv[i+2]==NULL) || (argv[i+3]==NULL) || (argv[i+4]==NULL) )
+                                       throw "-rename_section missing <segment> <section> <segment> <section>";
+                               addSectionRename(argv[i+1], argv[i+2], argv[i+3], argv[i+4]);
+                               i += 4;
+                       }
+                       else if ( strcmp(arg, "-no_branch_islands") == 0 ) {
+                               fAllowBranchIslands = false;
+                       }
+                       // put this last so that it does not interfer with other options starting with 'i'
+                       else if ( strncmp(arg, "-i", 2) == 0 ) {
+                               const char* colon = strchr(arg, ':');
+                               if ( colon == NULL )
+                                       throwf("unknown option: %s", arg);
+                               Options::AliasPair pair;
+                               char* temp = new char[colon-arg];
+                               strlcpy(temp, &arg[2], colon-arg-1);
+                               pair.realName = &colon[1];
+                               pair.alias = temp;
+                               fAliases.push_back(pair);
                        }
                        else {
                                throwf("unknown option: %s", arg);
                        }
+            
+            if (snapshotArgCount == -1)
+                snapshotArgCount = i-snapshotArgIndex+1;
+            if (snapshotArgCount > 0)
+                fLinkSnapshot.addSnapshotLinkArg(snapshotArgIndex, snapshotArgCount, snapshotFileArgIndex);
                }
                else {
                        FileInfo info = findFile(arg);
+                       info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)i);
                        if ( strcmp(&info.path[strlen(info.path)-2], ".a") == 0 )
                                addLibrary(info);
                        else
@@ -2513,8 +2998,13 @@ void Options::parse(int argc, const char* argv[])
        
        // if a -lazy option was used, implicitly link in lazydylib1.o
        if ( fUsingLazyDylibLinking ) {
-               addLibrary(findLibrary("lazydylib1.o"));
+               FileInfo info = findLibrary("lazydylib1.o");
+               info.ordinal = ld::File::Ordinal::makeArgOrdinal((uint16_t)argc);
+               addLibrary(info);
        }
+    
+    if (fSnapshotRequested)
+        fLinkSnapshot.createSnapshot();
 }
 
 
@@ -2537,21 +3027,64 @@ void Options::buildSearchPaths(int argc, const char* argv[])
        frameworkPaths.reserve(10);
        // scan through argv looking for -L, -F, -Z, and -syslibroot options
        for(int i=0; i < argc; ++i) {
-               if ( (argv[i][0] == '-') && (argv[i][1] == 'L') )
-                       libraryPaths.push_back(&argv[i][2]);
-               else if ( (argv[i][0] == '-') && (argv[i][1] == 'F') )
-                       frameworkPaths.push_back(&argv[i][2]);
+               if ( (argv[i][0] == '-') && (argv[i][1] == 'L') ) {
+                       const char* libSearchDir = &argv[i][2];
+                       // Allow either "-L{path}" or "-L {path}".
+                       if (argv[i][2] == '\0') {
+                               // -L {path}.  Make sure there is an argument following this.
+                               const char* path = argv[++i];
+                               if ( path == NULL )
+                                       throw "-L missing argument";
+                               libSearchDir = path;
+                       }
+                       if ( libSearchDir[0] == '\0' ) 
+                               throw "-L must be immediately followed by a directory path (no space)";
+                       struct stat statbuf;
+                       if ( stat(libSearchDir, &statbuf) == 0 ) {
+                               if ( statbuf.st_mode & S_IFDIR )
+                                       libraryPaths.push_back(libSearchDir);
+                               else
+                                       warning("path '%s' following -L not a directory", libSearchDir);
+                       }
+                       else {
+                               warning("directory not found for option '-L%s'", libSearchDir);
+                       }
+               }
+               else if ( (argv[i][0] == '-') && (argv[i][1] == 'F') ) {
+                       const char* frameworkSearchDir = &argv[i][2];
+                       // Allow either "-F{path}" or "-F {path}".
+                       if (argv[i][2] == '\0') {
+                               // -F {path}.  Make sure there is an argument following this.
+                               const char* path = argv[++i];
+                               if ( path == NULL )
+                                       throw "-F missing argument";
+                               frameworkSearchDir = path;
+                       }
+                       if ( frameworkSearchDir[0] == '\0' ) 
+                               throw "-F must be immediately followed by a directory path (no space)";
+                       struct stat statbuf;
+                       if ( stat(frameworkSearchDir, &statbuf) == 0 ) {
+                               if ( statbuf.st_mode & S_IFDIR )
+                                       frameworkPaths.push_back(frameworkSearchDir);
+                               else
+                                       warning("path '%s' following -F not a directory", frameworkSearchDir);
+                       }
+                       else {
+                               warning("directory not found for option '-F%s'", frameworkSearchDir);
+                       }
+               }
                else if ( strcmp(argv[i], "-Z") == 0 )
                        addStandardLibraryDirectories = false;
                else if ( strcmp(argv[i], "-v") == 0 ) {
                        fVerbose = true;
                        extern const char ldVersionString[];
                        fprintf(stderr, "%s", ldVersionString);
+                       fprintf(stderr, "configured to support archs: %s\n", ALL_SUPPORTED_ARCHS);
                         // if only -v specified, exit cleanly
                         if ( argc == 2 ) {
-#if LTO_SUPPORT
-                               printLTOVersion(*this);
-#endif
+                               const char* ltoVers = lto::version();
+                               if ( ltoVers != NULL )
+                                       fprintf(stderr, "LTO support using: %s\n", ltoVers);
                                exit(0);
                        }
                }
@@ -2562,12 +3095,23 @@ void Options::buildSearchPaths(int argc, const char* argv[])
                        fSDKPaths.push_back(path);
                }
                else if ( strcmp(argv[i], "-search_paths_first") == 0 ) {
-                       // ??? Deprecate when we get -Bstatic/-Bdynamic.
                        fLibrarySearchMode = kSearchDylibAndArchiveInEachDir;
                }
+               else if ( strcmp(argv[i], "-search_dylibs_first") == 0 ) {
+                       fLibrarySearchMode = kSearchAllDirsForDylibsThenAllDirsForArchives;
+               }
                else if ( strcmp(argv[i], "-w") == 0 ) {
                        sEmitWarnings = false;
                }
+               else if ( strcmp(argv[i], "-fatal_warnings") == 0 ) {
+                       sFatalWarnings = true;
+               }
+               else if ( strcmp(argv[i], "-dependency_info") == 0 ) {
+                        const char* path = argv[++i];
+                        if ( path == NULL )
+                               throw "-dependency_info missing <path>";
+                       fDependencyInfoPath = path;
+               }
        }
        int standardLibraryPathsStartIndex = libraryPaths.size();
        int standardFrameworkPathsStartIndex = frameworkPaths.size();
@@ -2685,12 +3229,12 @@ void Options::parsePreCommandLineEnvironmentSettings()
 {
        if ((getenv("LD_TRACE_ARCHIVES") != NULL)
                || (getenv("RC_TRACE_ARCHIVES") != NULL))
-           fReaderOptions.fTraceArchives = true;
+           fTraceArchives = true;
 
        if ((getenv("LD_TRACE_DYLIBS") != NULL)
                || (getenv("RC_TRACE_DYLIBS") != NULL)) {
-           fReaderOptions.fTraceDylibs = true;
-               fReaderOptions.fTraceIndirectDylibs = true;
+           fTraceDylibs = true;
+               fTraceIndirectDylibs = true;
        }
 
        if (getenv("RC_TRACE_DYLIB_SEARCHING") != NULL) {
@@ -2700,8 +3244,8 @@ void Options::parsePreCommandLineEnvironmentSettings()
        if (getenv("LD_PRINT_OPTIONS") != NULL)
                fPrintOptions = true;
 
-       if (fReaderOptions.fTraceDylibs || fReaderOptions.fTraceArchives)
-               fReaderOptions.fTraceOutputFile = getenv("LD_TRACE_FILE");
+       if (fTraceDylibs || fTraceArchives)
+               fTraceOutputFile = getenv("LD_TRACE_FILE");
 
        if (getenv("LD_PRINT_ORDER_FILE_STATISTICS") != NULL)
                fPrintOrderFileStatistics = true;
@@ -2715,13 +3259,24 @@ void Options::parsePreCommandLineEnvironmentSettings()
        if (getenv("LD_ALLOW_CPU_SUBTYPE_MISMATCHES") != NULL)
                fAllowCpuSubtypeMismatches = true;
        
-       // for now disable compressed linkedit functionality
-       if ( getenv("LD_NO_COMPACT_LINKEDIT") != NULL ) {
-               fMakeCompressedDyldInfo = false;
-               fMakeClassicDyldInfo = true;
-       }
-
        sWarningsSideFilePath = getenv("LD_WARN_FILE");
+       
+       const char* customDyldPath = getenv("LD_DYLD_PATH");
+       if ( customDyldPath != NULL ) 
+               fDyldInstallPath = customDyldPath;
+    
+    const char* debugArchivePath = getenv("LD_DEBUG_SNAPSHOT");
+    if (debugArchivePath != NULL) {
+        fLinkSnapshot.setSnapshotMode(Snapshot::SNAPSHOT_DEBUG);
+        if (strlen(debugArchivePath) > 0)
+            fLinkSnapshot.setSnapshotPath(debugArchivePath);
+        fSnapshotRequested = true;
+    }
+
+    const char* pipeFdString = getenv("LD_PIPELINE_FIFO");
+    if (pipeFdString != NULL) {
+               fPipelineFifo = pipeFdString;
+    }
 }
 
 
@@ -2743,13 +3298,13 @@ void Options::parsePostCommandLineEnvironmentSettings()
        }
        
        // allow build system to force on dead-code-stripping
-       if ( fDeadStrip == kDeadStripOff ) {
+       if ( !fDeadStrip ) {
                if ( getenv("LD_DEAD_STRIP") != NULL ) {
                        switch (fOutputKind) {
                                case Options::kDynamicLibrary:
                                case Options::kDynamicExecutable:
                                case Options::kDynamicBundle:
-                                       fDeadStrip = kDeadStripOn;
+                                       fDeadStrip = true;
                                        break;
                                case Options::kPreload:
                                case Options::kObjectFile:
@@ -2764,6 +3319,13 @@ void Options::parsePostCommandLineEnvironmentSettings()
        // allow build system to force on -warn_commons
        if ( getenv("LD_WARN_COMMONS") != NULL )
                fWarnCommons = true;
+       
+       // allow B&I to set default -source_version
+       if ( fSourceVersion == 0 ) {
+               const char* vers = getenv("RC_ProjectSourceVersion");
+               if ( vers != NULL )
+                       fSourceVersion = parseVersionNumber64(vers);
+       }
                
 }
 
@@ -2772,48 +3334,72 @@ void Options::reconfigureDefaults()
        // sync reader options
        switch ( fOutputKind ) {
                case Options::kObjectFile:
-                       fReaderOptions.fForFinalLinkedImage = false;
+                       fForFinalLinkedImage = false;
                        break;
                case Options::kDyld:
-                       fReaderOptions.fForDyld = true;
-                       fReaderOptions.fForFinalLinkedImage = true;
-                       fReaderOptions.fNoEHLabels = true;
+                       fForDyld = true;
+                       fForFinalLinkedImage = true;
+                       fNoEHLabels = true;
                        break;
                case Options::kDynamicLibrary:
                case Options::kDynamicBundle:
                case Options::kKextBundle:
-                       fReaderOptions.fForFinalLinkedImage = true;
-                       fReaderOptions.fNoEHLabels = true;
+                       fForFinalLinkedImage = true;
+                       fNoEHLabels = true;
                        break;
                case Options::kDynamicExecutable:
                case Options::kStaticExecutable:
                case Options::kPreload:
-                       fReaderOptions.fLinkingMainExecutable = true;
-                       fReaderOptions.fForFinalLinkedImage = true;
-                       fReaderOptions.fNoEHLabels = true;
+                       fLinkingMainExecutable = true;
+                       fForFinalLinkedImage = true;
+                       fNoEHLabels = true;
                        break;
        }
 
        // set default min OS version
-       if ( (fReaderOptions.fMacVersionMin == ObjectFile::ReaderOptions::kMinMacVersionUnset)
-               && (fReaderOptions.fIPhoneVersionMin == ObjectFile::ReaderOptions::kMinIPhoneVersionUnset) ) {
+       if ( (fMacVersionMin == ld::macVersionUnset)
+               && (fIOSVersionMin == ld::iOSVersionUnset) ) {
                // if neither -macosx_version_min nor -iphoneos_version_min used, try environment variables
                const char* macVers = getenv("MACOSX_DEPLOYMENT_TARGET");
                const char* iPhoneVers = getenv("IPHONEOS_DEPLOYMENT_TARGET");
+               const char* iOSVers = getenv("IOS_DEPLOYMENT_TARGET");
+               const char* iOSSimulatorVers = getenv("IOS_SIMULATOR_DEPLOYMENT_TARGET");
                if ( macVers != NULL ) 
                        setMacOSXVersionMin(macVers);
                else if ( iPhoneVers != NULL )
-                       setIPhoneVersionMin(iPhoneVers);
+                       setIOSVersionMin(iPhoneVers);
+               else if ( iOSVers != NULL )
+                       setIOSVersionMin(iOSVers);
+               else if ( iOSSimulatorVers != NULL )
+                       setIOSVersionMin(iOSSimulatorVers);
                else {
                        // if still nothing, set default based on architecture
                        switch ( fArchitecture ) {
                                case CPU_TYPE_I386:
                                case CPU_TYPE_X86_64:
-                               case CPU_TYPE_POWERPC:                  
-                                       fReaderOptions.fMacVersionMin = ObjectFile::ReaderOptions::k10_6; // FIX FIX, this really should be a check of the OS version the linker is running o
+                                       if ( (fOutputKind != Options::kObjectFile) && (fOutputKind != Options::kPreload) ) {
+                       #ifdef DEFAULT_MACOSX_MIN_VERSION
+                                               warning("-macosx_version_min not specified, assuming " DEFAULT_MACOSX_MIN_VERSION);
+                                               setMacOSXVersionMin(DEFAULT_MACOSX_MIN_VERSION);
+                       #else
+                                               warning("-macosx_version_min not specified, assuming 10.6");
+                                               fMacVersionMin = ld::mac10_6;
+                       #endif          
+                                       }
                                        break;
                                case CPU_TYPE_ARM:
-                                       fReaderOptions.fIPhoneVersionMin = ObjectFile::ReaderOptions::k2_0; 
+                                       if ( (fOutputKind != Options::kObjectFile) && (fOutputKind != Options::kPreload) ) {
+                       #if defined(DEFAULT_IPHONEOS_MIN_VERSION)
+                                               warning("-ios_version_min not specified, assuming " DEFAULT_IPHONEOS_MIN_VERSION);
+                                               setIOSVersionMin(DEFAULT_IPHONEOS_MIN_VERSION);
+                       #else
+                                               warning("-ios_version_min not specified, assuming 6.0");
+                                               setIOSVersionMin("6.0");
+                       #endif
+                                       }
+                                       break;
+                               default:
+                                       // architecture will be infered later by examining .o files
                                        break;
                        }
                }
@@ -2823,38 +3409,83 @@ void Options::reconfigureDefaults()
        // adjust min based on architecture
        switch ( fArchitecture ) {
                case CPU_TYPE_I386:
-                       if ( fReaderOptions.fMacVersionMin < ObjectFile::ReaderOptions::k10_4 ) {
+                       if ( (fMacVersionMin < ld::mac10_4) && (fIOSVersionMin == ld::iOSVersionUnset) ) {
                                //warning("-macosx_version_min should be 10.4 or later for i386");
-                               fReaderOptions.fMacVersionMin = ObjectFile::ReaderOptions::k10_4;
-                       }
-                       break;
-               case CPU_TYPE_POWERPC64:
-                       if ( fReaderOptions.fMacVersionMin < ObjectFile::ReaderOptions::k10_4 ) {
-                               //warning("-macosx_version_min should be 10.4 or later for ppc64");
-                               fReaderOptions.fMacVersionMin = ObjectFile::ReaderOptions::k10_4;
+                               fMacVersionMin = ld::mac10_4;
                        }
                        break;
                case CPU_TYPE_X86_64:
-                       if ( fReaderOptions.fMacVersionMin < ObjectFile::ReaderOptions::k10_4 ) {
+                       if ( (fMacVersionMin < ld::mac10_4) && (fIOSVersionMin == ld::iOSVersionUnset) ) {
                                //warning("-macosx_version_min should be 10.4 or later for x86_64");
-                               fReaderOptions.fMacVersionMin = ObjectFile::ReaderOptions::k10_4;
+                               fMacVersionMin = ld::mac10_4;
+                       }
+                       break;
+               case CPU_TYPE_ARM64:
+                       if ( fIOSVersionMin < ld::iOS_7_0 ) {
+                               //warning("-mios_version_min should be 7.0 or later for arm64");
+                               fIOSVersionMin = ld::iOS_7_0;
                        }
                        break;
        }
        
+       // default to adding functions start for dynamic code, static code must opt-in
+       switch ( fOutputKind ) {
+               case Options::kPreload:
+               case Options::kStaticExecutable:
+               case Options::kKextBundle:
+                       if ( fDataInCodeInfoLoadCommandForcedOn )
+                               fDataInCodeInfoLoadCommand = true;
+                       if ( fFunctionStartsForcedOn )
+                               fFunctionStartsLoadCommand = true;
+                       break;
+               case Options::kObjectFile:
+                       if ( !fDataInCodeInfoLoadCommandForcedOff )
+                               fDataInCodeInfoLoadCommand = true;
+                       if ( fFunctionStartsForcedOn )
+                               fFunctionStartsLoadCommand = true;
+                       break;
+               case Options::kDynamicExecutable:
+               case Options::kDyld:
+               case Options::kDynamicLibrary:
+               case Options::kDynamicBundle:
+                       if ( !fDataInCodeInfoLoadCommandForcedOff )
+                               fDataInCodeInfoLoadCommand = true;
+                       if ( !fFunctionStartsForcedOff )
+                               fFunctionStartsLoadCommand = true;
+                       break;
+       }
+               
        // adjust kext type based on architecture
        if ( fOutputKind == kKextBundle ) {
                switch ( fArchitecture ) {
                        case CPU_TYPE_X86_64:
                                // x86_64 uses new MH_KEXT_BUNDLE type
-                               fMakeClassicDyldInfo = true; 
                                fMakeCompressedDyldInfo = false;
+                               fMakeCompressedDyldInfoForceOff = true;
                                fAllowTextRelocs = true;
                                fUndefinedTreatment = kUndefinedDynamicLookup;
                                break;
-                       case CPU_TYPE_POWERPC:
-                       case CPU_TYPE_I386:
+                       case CPU_TYPE_ARM64:
+                               // arm64 uses new MH_KEXT_BUNDLE type
+                               fMakeCompressedDyldInfo = false;
+                               fMakeCompressedDyldInfoForceOff = true;
+                               fAllowTextRelocs = false; 
+                               fKextsUseStubs = true;
+                               fUndefinedTreatment = kUndefinedDynamicLookup;
+                               break;
                        case CPU_TYPE_ARM:
+                               if ( fIOSVersionMin >= ld::iOS_5_0 ) {
+                    // iOS 5.0 and later use new MH_KEXT_BUNDLE type
+                    fMakeCompressedDyldInfo = false;
+                    fMakeCompressedDyldInfoForceOff = true;
+                                       // kexts are PIC in iOS 6.0 and later
+                                       fAllowTextRelocs = (fIOSVersionMin < ld::iOS_6_0);
+                                       fKextsUseStubs = !fAllowTextRelocs;
+                    fUndefinedTreatment = kUndefinedDynamicLookup;
+                                       break;
+                               }
+                               // else use object file
+                       case CPU_TYPE_I386:
                                // use .o files
                                fOutputKind = kObjectFile;
                                break;
@@ -2863,8 +3494,8 @@ void Options::reconfigureDefaults()
 
        // disable implicit dylibs when targeting 10.3
        // <rdar://problem/5451987> add option to disable implicit load commands for indirectly used public dylibs
-       if ( !minOS(ObjectFile::ReaderOptions::k10_4, ObjectFile::ReaderOptions::k2_0) )
-               fReaderOptions.fImplicitlyLinkPublicDylibs = false;
+       if ( !minOS(ld::mac10_4, ld::iOS_2_0) )
+               fImplicitlyLinkPublicDylibs = false;
 
 
        // allow build system to force linker to ignore -prebind
@@ -2896,9 +3527,8 @@ void Options::reconfigureDefaults()
        
        // split segs only allowed for dylibs
        if ( fSplitSegs ) {
-        // split seg only supported for ppc, i386, and arm.
+        // split seg only supported for i386, and arm.
         switch ( fArchitecture ) {
-            case CPU_TYPE_POWERPC:
             case CPU_TYPE_I386:
                 if ( fOutputKind != Options::kDynamicLibrary )
                     fSplitSegs = false;
@@ -2923,6 +3553,37 @@ void Options::reconfigureDefaults()
                }
        }
 
+       // set too-large size
+       switch ( fArchitecture ) {
+               case CPU_TYPE_I386:
+                       fMaxAddress = 0xFFFFFFFF;
+                       break;
+               case CPU_TYPE_X86_64:
+                       break;
+               case CPU_TYPE_ARM:
+                       switch ( fOutputKind ) {
+                               case Options::kDynamicExecutable:
+                               case Options::kDynamicLibrary:
+                               case Options::kDynamicBundle:
+                                       // user land code is limited to low 1GB
+                                       fMaxAddress = 0x2FFFFFFF;
+                                       break;
+                               case Options::kStaticExecutable:
+                               case Options::kObjectFile:
+                               case Options::kDyld:
+                               case Options::kPreload:
+                               case Options::kKextBundle:
+                                       fMaxAddress = 0xFFFFFFFF;
+                                       break;
+                       }
+                       // range check -seg1addr for ARM
+                       if ( fBaseAddress > fMaxAddress ) {
+                               warning("ignoring -seg1addr 0x%08llX.  Address out of range.", fBaseAddress);
+                               fBaseAddress = 0;
+                       }
+                       break;
+       }
+
        // <rdar://problem/6138961> -r implies no prebinding for all architectures
        if ( fOutputKind == Options::kObjectFile )
                fPrebind = false;                       
@@ -2930,17 +3591,20 @@ void Options::reconfigureDefaults()
        // disable prebinding depending on arch and min OS version
        if ( fPrebind ) {
                switch ( fArchitecture ) {
-                       case CPU_TYPE_POWERPC:
                        case CPU_TYPE_I386:
-                               if ( fReaderOptions.fMacVersionMin == ObjectFile::ReaderOptions::k10_4 ) {
+                               if ( fMacVersionMin == ld::mac10_4 ) {
                                        // in 10.4 only split seg dylibs are prebound
                                        if ( (fOutputKind != Options::kDynamicLibrary) || ! fSplitSegs )
                                                fPrebind = false;
                                }
-                               else if ( fReaderOptions.fMacVersionMin >= ObjectFile::ReaderOptions::k10_5 ) {
+                               else if ( fMacVersionMin >= ld::mac10_5 ) {
                                        // in 10.5 nothing is prebound
                                        fPrebind = false;
                                }
+                               else if ( fIOSVersionMin != ld::iOSVersionUnset ) {
+                                       // nothing in simulator is prebound
+                                       fPrebind = false;
+                               }
                                else {
                                        // in 10.3 and earlier only dylibs and main executables could be prebound
                                        switch ( fOutputKind ) {
@@ -2960,7 +3624,6 @@ void Options::reconfigureDefaults()
                                        }
                                }
                                break;
-                       case CPU_TYPE_POWERPC64:
                        case CPU_TYPE_X86_64:
                                fPrebind = false;
                                break;
@@ -2990,21 +3653,23 @@ void Options::reconfigureDefaults()
 
        // determine if info for shared region should be added
        if ( fOutputKind == Options::kDynamicLibrary ) {
-               if ( minOS(ObjectFile::ReaderOptions::k10_5, ObjectFile::ReaderOptions::k3_1) )
+               if ( minOS(ld::mac10_5, ld::iOS_3_1) )
                        if ( !fPrebind )
                                if ( (strncmp(this->installPath(), "/usr/lib/", 9) == 0)
                                        || (strncmp(this->installPath(), "/System/Library/", 16) == 0) )
                                        fSharedRegionEligible = true;
        }
-       
+       else if ( fOutputKind == Options::kDyld ) {
+        // <rdar://problem/10111122> Enable dyld to be put into the dyld shared cache
+        fSharedRegionEligible = true;
+       }
+    
        // figure out if module table is needed for compatibility with old ld/dyld
        if ( fOutputKind == Options::kDynamicLibrary ) {
                switch ( fArchitecture ) {
-                       case CPU_TYPE_POWERPC:  // 10.3 and earlier dyld requires a module table
-                       case CPU_TYPE_I386:             // ld_classic for 10.4.x requires a module table
-                               if ( fReaderOptions.fMacVersionMin <= ObjectFile::ReaderOptions::k10_5 )
-                                       fNeedsModuleTable = true;
-                               break;
+                       case CPU_TYPE_I386:
+                               if ( fIOSVersionMin != ld::iOSVersionUnset ) // simulator never needs modules
+                                       break;
                        case CPU_TYPE_ARM:
                                if ( fPrebind )
                                        fNeedsModuleTable = true; // redo_prebinding requires a module table
@@ -3014,50 +3679,53 @@ void Options::reconfigureDefaults()
        
        // <rdar://problem/5366363> -r -x implies -S
        if ( (fOutputKind == Options::kObjectFile) && (fLocalSymbolHandling == kLocalSymbolsNone) )
-               fReaderOptions.fDebugInfoStripping = ObjectFile::ReaderOptions::kDebugInfoNone;                 
-               
+               fDebugInfoStripping = Options::kDebugInfoNone;                  
+
+       // <rdar://problem/15252891> -r implies -no_uuid
+       if ( fOutputKind == Options::kObjectFile )
+               fUUIDMode = kUUIDNone;
+
        // choose how to process unwind info
        switch ( fArchitecture ) {
                case CPU_TYPE_I386:             
                case CPU_TYPE_X86_64:           
+               case CPU_TYPE_ARM64:            
                        switch ( fOutputKind ) {
                                case Options::kObjectFile:
                                case Options::kStaticExecutable:
                                case Options::kPreload:
                                case Options::kKextBundle:
-                                       fReaderOptions.fAddCompactUnwindEncoding = false;
+                                       fAddCompactUnwindEncoding = false;
                                        break;
                                case Options::kDyld:
                                case Options::kDynamicLibrary:
                                case Options::kDynamicBundle:
                                case Options::kDynamicExecutable:
-                                       //if ( fReaderOptions.fAddCompactUnwindEncoding && (fReaderOptions.fVersionMin >= ObjectFile::ReaderOptions::k10_6) )
-                                       //      fReaderOptions.fRemoveDwarfUnwindIfCompactExists = true;
+                                       //if ( fAddCompactUnwindEncoding && (fVersionMin >= ld::mac10_6) )
+                                       //      fRemoveDwarfUnwindIfCompactExists = true;
                                        break;
                        }
                        break;
-               case CPU_TYPE_POWERPC:
-               case CPU_TYPE_POWERPC64:                
                case CPU_TYPE_ARM:
-                       fReaderOptions.fAddCompactUnwindEncoding = false;
-                       fReaderOptions.fRemoveDwarfUnwindIfCompactExists = false;
+                       fAddCompactUnwindEncoding = false;
+                       fRemoveDwarfUnwindIfCompactExists = false;
                        break;
                case 0:
                        // if -arch is missing, assume we don't want compact unwind info
-                       fReaderOptions.fAddCompactUnwindEncoding = false;
+                       fAddCompactUnwindEncoding = false;
                        break;
        }
                
-       // only ARM main executables can be encrypted
+       // only iOS main executables should be encrypted
        if ( fOutputKind != Options::kDynamicExecutable )
                fEncryptable = false;
-       if ( fArchitecture != CPU_TYPE_ARM )
+       if ( (fArchitecture != CPU_TYPE_ARM) && (fArchitecture != CPU_TYPE_ARM64) )
                fEncryptable = false;
 
        // don't move inits in dyld because dyld wants certain
        // entries point at stable locations at the start of __text
        if ( fOutputKind == Options::kDyld ) 
-               fReaderOptions.fAutoOrderInitializers = false;
+               fAutoOrderInitializers = false;
                
                
        // disable __data ordering for some output kinds
@@ -3075,57 +3743,51 @@ void Options::reconfigureDefaults()
                        break;
        }
        
+       // only use compressed LINKEDIT for final linked images
+       switch ( fOutputKind ) {
+               case Options::kDynamicExecutable:
+               case Options::kDynamicLibrary:
+               case Options::kDynamicBundle:
+                       break;
+               case Options::kPreload:
+               case Options::kStaticExecutable:
+               case Options::kObjectFile:
+               case Options::kDyld:
+               case Options::kKextBundle:
+                       fMakeCompressedDyldInfoForceOff = true;
+                       break;
+       }
+       if ( fMakeCompressedDyldInfoForceOff ) 
+               fMakeCompressedDyldInfo = false;
+
+       
        // only use compressed LINKEDIT for:
-       //                      x86_64 and i386 on Mac OS X 10.6 or later
-       //                      arm on iPhoneOS 3.1 or later
+       //                      Mac OS X 10.6 or later
+       //                      iOS 3.1 or later
        if ( fMakeCompressedDyldInfo ) {
-               switch (fArchitecture) {
-                       case CPU_TYPE_I386:
-                       case CPU_TYPE_X86_64:
-                               if ( fReaderOptions.fMacVersionMin >= ObjectFile::ReaderOptions::k10_6 ) 
-                                       fMakeClassicDyldInfo = false; 
-                               else if ( fReaderOptions.fMacVersionMin < ObjectFile::ReaderOptions::k10_5 )
-                                       fMakeCompressedDyldInfo = false;
-                               break;
-            case CPU_TYPE_ARM:
-                               if ( fReaderOptions.fIPhoneVersionMin >= ObjectFile::ReaderOptions::k3_1 ) 
-                                       fMakeClassicDyldInfo = false; 
-                               else if ( fReaderOptions.fIPhoneVersionMin < ObjectFile::ReaderOptions::k3_1 )
-                                       fMakeCompressedDyldInfo = false;
-                               break;
-                       case CPU_TYPE_POWERPC:
-                       case CPU_TYPE_POWERPC64:
-                       default:
-                               fMakeCompressedDyldInfo = false;
-               }
+               if ( !minOS(ld::mac10_6, ld::iOS_3_1) )
+                       fMakeCompressedDyldInfo = false;
        }
-       
 
-       // only use compressed LINKEDIT for final linked images
-       if ( fMakeCompressedDyldInfo ) {
-               switch ( fOutputKind ) {
-                       case Options::kDynamicExecutable:
-                       case Options::kDynamicLibrary:
-                       case Options::kDynamicBundle:
-                               break;
-                       case Options::kPreload:
-                       case Options::kStaticExecutable:
-                       case Options::kObjectFile:
-                       case Options::kDyld:
-                       case Options::kKextBundle:
-                               fMakeCompressedDyldInfo = false;
-                               break;
-               }
+       // only ARM and x86_64 enforces that cpu-sub-types must match
+       switch ( fArchitecture ) {
+               case CPU_TYPE_ARM:
+               case CPU_TYPE_X86_64:
+                       break;
+               case CPU_TYPE_I386:
+               case CPU_TYPE_ARM64:
+                       fAllowCpuSubtypeMismatches = true;
+                       break;
        }
-       fReaderOptions.fMakeCompressedDyldInfo = fMakeCompressedDyldInfo;
                
-       // only ARM enforces that cpu-sub-types must match
-       if ( fArchitecture != CPU_TYPE_ARM )
-               fAllowCpuSubtypeMismatches = true;
                
        // only final linked images can not optimize zero fill sections
        if ( fOutputKind == Options::kObjectFile )
-               fReaderOptions.fOptimizeZeroFill = true;
+               fOptimizeZeroFill = true;
+
+       // all undefines in -r mode
+//     if ( fOutputKind == Options::kObjectFile )
+//             fUndefinedTreatment = kUndefinedSuppress;
 
        // only dynamic final linked images should warn about use of commmons
        if ( fWarnCommons ) {
@@ -3145,13 +3807,302 @@ void Options::reconfigureDefaults()
        }
        
        // Mac OS X 10.5 and iPhoneOS 2.0 support LC_REEXPORT_DYLIB
-       if ( minOS(ObjectFile::ReaderOptions::k10_5, ObjectFile::ReaderOptions::k2_0) )
+       if ( minOS(ld::mac10_5, ld::iOS_2_0) )
                fUseSimplifiedDylibReExports = true;
-}
+       
+       // Mac OS X 10.7 and iOS 4.2 support LC_LOAD_UPWARD_DYLIB
+       if ( minOS(ld::mac10_7, ld::iOS_4_2) && (fOutputKind == kDynamicLibrary) )
+               fCanUseUpwardDylib = true;
+               
+       // MacOSX 10.7 defaults to PIE
+       if ( ((fArchitecture == CPU_TYPE_X86_64) || (fArchitecture == CPU_TYPE_I386))
+               && (fOutputKind == kDynamicExecutable)
+               && (fMacVersionMin >= ld::mac10_7) ) {
+                       fPositionIndependentExecutable = true;
+       }
 
-void Options::checkIllegalOptionCombinations()
-{
-       // check -undefined setting
+       // armv7 for iOS4.3 defaults to PIE
+       if ( (fArchitecture == CPU_TYPE_ARM) 
+               && fArchSupportsThumb2
+               && (fOutputKind == kDynamicExecutable) 
+               && (fIOSVersionMin >= ld::iOS_4_3) ) {
+                       fPositionIndependentExecutable = true;
+       }
+
+       // -no_pie anywhere on command line disable PIE
+       if ( fDisablePositionIndependentExecutable )
+               fPositionIndependentExecutable = false;
+
+       // arm64 is always PIE
+       if ( (fArchitecture == CPU_TYPE_ARM64) && (fOutputKind == kDynamicExecutable) ) {
+               fPositionIndependentExecutable = true;
+       }
+
+       // set fOutputSlidable
+       switch ( fOutputKind ) {
+               case Options::kObjectFile:
+                       fOutputSlidable = false;
+                       break;
+               case Options::kStaticExecutable:
+               case Options::kDynamicExecutable:
+                       fOutputSlidable = fPositionIndependentExecutable;
+                       break;
+               case Options::kPreload:
+                       fOutputSlidable = fPIEOnCommandLine;
+                       break;
+               case Options::kDyld:
+               case Options::kDynamicLibrary:
+               case Options::kDynamicBundle:
+               case Options::kKextBundle:
+                       fOutputSlidable = true;
+                       break;
+       }
+
+       // let linker know if thread local variables are supported
+       if ( fMacVersionMin >= ld::mac10_7 ) {
+               fTLVSupport = true;
+       }
+       else if ( (fArchitecture == CPU_TYPE_ARM64) && (fIOSVersionMin >= 0x00080000) ) {
+               fTLVSupport = true;
+       }
+
+       // default to adding version load command for dynamic code, static code must opt-in
+       switch ( fOutputKind ) {
+               case Options::kObjectFile:
+                       fVersionLoadCommand = false;
+                       break;
+               case Options::kStaticExecutable:
+               case Options::kPreload:
+               case Options::kKextBundle:
+                       if ( fVersionLoadCommandForcedOn )
+                               fVersionLoadCommand = true;
+                       break;
+               case Options::kDynamicExecutable:
+               case Options::kDyld:
+               case Options::kDynamicLibrary:
+               case Options::kDynamicBundle:
+                       if ( !fVersionLoadCommandForcedOff )
+                               fVersionLoadCommand = true;
+                       break;
+       }
+       
+       // support re-export of individual symbols in MacOSX 10.7 and iOS 4.2
+       if ( (fOutputKind == kDynamicLibrary) && minOS(ld::mac10_7, ld::iOS_4_2) )
+               fCanReExportSymbols = true;
+       
+       // ObjC optimization is only in dynamic final linked images
+       switch ( fOutputKind ) {
+               case Options::kObjectFile:
+               case Options::kStaticExecutable:
+               case Options::kPreload:
+               case Options::kKextBundle:
+               case Options::kDyld:
+                       fObjcCategoryMerging = false;
+                       break;
+               case Options::kDynamicExecutable:
+               case Options::kDynamicLibrary:
+               case Options::kDynamicBundle:
+                       break;
+       }
+
+       // i386 main executables linked on Mac OS X 10.7 default to NX heap
+       // regardless of target unless overriden with -allow_heap_execute anywhere
+       // on the command line
+       if ( (fArchitecture == CPU_TYPE_I386) && (fOutputKind == kDynamicExecutable) && !fDisableNonExecutableHeap)
+               fNonExecutableHeap = true;
+               
+       // Use LC_MAIN instead of LC_UNIXTHREAD for newer OSs
+       switch ( fOutputKind ) {
+               case Options::kDynamicExecutable:
+                       if ( fEntryPointLoadCommandForceOn ) {
+                               fEntryPointLoadCommand = true;
+                               fEntryName = "_main";
+                       }
+                       else if ( fEntryPointLoadCommandForceOff ) {
+                               fNeedsThreadLoadCommand = true;
+                       }
+                       else {
+                               if ( minOS(ld::mac10_8, ld::iOS_6_0) ) {
+                                       fEntryPointLoadCommand = true;
+                                       fEntryName = "_main";
+                               }
+                               else
+                                       fNeedsThreadLoadCommand = true;
+                       }
+                       break;
+               case Options::kObjectFile:
+               case Options::kKextBundle:
+               case Options::kDynamicLibrary:
+               case Options::kDynamicBundle:
+                       break;
+                       
+               case Options::kStaticExecutable:
+               case Options::kPreload:
+               case Options::kDyld:
+                       fNeedsThreadLoadCommand = true;
+                       break;
+       }
+       
+       // add LC_SOURCE_VERSION
+       switch ( fOutputKind ) {
+               case Options::kDynamicExecutable:
+               case Options::kKextBundle:
+               case Options::kDynamicLibrary:
+               case Options::kDynamicBundle:
+               case Options::kDyld:
+               case Options::kStaticExecutable:
+                       if ( fSourceVersionLoadCommandForceOn ) {
+                               fSourceVersionLoadCommand = true;
+                       }
+                       else if ( fSourceVersionLoadCommandForceOff ) {
+                               fSourceVersionLoadCommand = false;
+                       }
+                       else {
+                               if ( minOS(ld::mac10_8, ld::iOS_6_0) ) {
+                                       fSourceVersionLoadCommand = true;
+                               }
+                               else
+                                       fSourceVersionLoadCommand = false;
+                       }
+                       break;
+               case Options::kObjectFile:
+               case Options::kPreload:
+                       fSourceVersionLoadCommand = false;
+                       break;
+       }
+       
+       
+       // add LC_DYLIB_CODE_SIGN_DRS
+       switch ( fOutputKind ) {
+               case Options::kDynamicExecutable:
+               case Options::kDynamicLibrary:
+               case Options::kDynamicBundle:
+                       if ( fDependentDRInfoForcedOn ) {
+                               fDependentDRInfo = true;
+                       }
+                       else if ( fDependentDRInfoForcedOff ) {
+                               fDependentDRInfo = false;
+                       }
+                       else {
+                               if ( minOS(ld::mac10_8, ld::iOS_6_0) ) 
+                                       fDependentDRInfo = true;
+                               else
+                                       fDependentDRInfo = false;
+                       }
+                       break;
+               case Options::kKextBundle:
+               case Options::kDyld:
+               case Options::kStaticExecutable:
+               case Options::kObjectFile:
+               case Options::kPreload:
+                       fDependentDRInfo = false;
+                       break;
+       }
+       
+       // if -sdk_version not on command line, infer from -syslibroot
+       if ( (fSDKVersion == 0) && (fSDKPaths.size() > 0) ) {
+               const char* sdkPath = fSDKPaths.front();
+               const char* end = &sdkPath[strlen(sdkPath)-1];
+               while ( !isdigit(*end) && (end > sdkPath) )
+                       --end;
+               const char* start = end-1;
+               while ( (isdigit(*start) || (*start == '.')) && (start > sdkPath))
+                       --start;
+               char sdkVersionStr[32];
+               int len = end-start+1;
+               if ( len > 2 ) {
+                       strlcpy(sdkVersionStr, start+1, len);
+                       fSDKVersion = parseVersionNumber32(sdkVersionStr);
+               }
+       }
+       
+       // if -sdk_version and -syslibroot not used, but targeting MacOSX, use current OS version
+       if ( (fSDKVersion == 0) && (fMacVersionMin != ld::macVersionUnset) ) {
+               // special case if RC_ProjectName and MACOSX_DEPLOYMENT_TARGET are both set that sdkversion=minos
+               if ( getenv("RC_ProjectName") && getenv("MACOSX_DEPLOYMENT_TARGET") ) {
+                       fSDKVersion = fMacVersionMin;
+               }
+               else {
+                       int mib[2] = { CTL_KERN, KERN_OSRELEASE };
+                       char kernVersStr[100];
+                       size_t strlen = sizeof(kernVersStr);
+                       if ( sysctl(mib, 2, kernVersStr, &strlen, NULL, 0) != -1 ) {
+                               uint32_t kernVers = parseVersionNumber32(kernVersStr);
+                               int minor = (kernVers >> 16) - 4;  // kernel major version is 4 ahead of x in 10.x
+                               fSDKVersion = 0x000A0000 + (minor << 8);
+                       }
+               }
+       }
+       
+       // allow trie based absolute symbols if targeting new enough OS
+       if ( fMakeCompressedDyldInfo ) {
+               if ( minOS(ld::mac10_9, ld::iOS_7_0) ) {
+                       // <rdar://problem/13179029> Allow absolute symbols in export trie for device but not simulator
+                       if ( !fTargetIOSSimulator ) 
+                               fAbsoluteSymbols = true;
+               }
+       }
+       
+       // <rdar://problem/12959510> iOS main executables now default to 16KB page size
+       if ( (fIOSVersionMin != ld::iOSVersionUnset) && (fOutputKind == Options::kDynamicExecutable) ) {
+               // <rdar://problem/13070042> Only third party apps should have 16KB page segments by default
+               if ( fEncryptable ) {
+                       if ( fSegmentAlignment == 4096 )
+                               fSegmentAlignment = 4096*4;
+               }
+       }
+  
+       // <rdar://problem/12258065> ARM64 needs 16KB page size for user land code
+       if ( fArchitecture == CPU_TYPE_ARM64 ) {
+               if ( fSegmentAlignment == 4096 ) {
+                       switch ( fOutputKind ) {
+                               case Options::kDynamicExecutable:
+                               case Options::kDynamicLibrary:
+                               case Options::kDynamicBundle:
+                               case Options::kDyld:
+                                       fSegmentAlignment = 4096*4;
+                                       break;
+                               case Options::kStaticExecutable:
+                               case Options::kKextBundle:
+                               case Options::kObjectFile:
+                               case Options::kPreload:
+                                       break;
+                       }
+               }
+       }
+       
+       // <rdar://problem/13624134> linker should not convert dwarf unwind if .o file has compact unwind section
+       switch ( fOutputKind ) {
+               case Options::kDynamicExecutable:
+               case Options::kDynamicLibrary:
+               case Options::kDynamicBundle:
+               case Options::kDyld:
+                       if ( fKeepDwarfUnwindForcedOn ) {
+                               fKeepDwarfUnwind = true;
+                       }
+                       else if ( fKeepDwarfUnwindForcedOff ) {
+                               fKeepDwarfUnwind = false;
+                       }
+                       else {
+                               if ( minOS(ld::mac10_9, ld::iOS_7_0) ) 
+                                       fKeepDwarfUnwind = false;
+                               else
+                                       fKeepDwarfUnwind = true;
+                       }
+                       break;
+               case Options::kKextBundle:
+               case Options::kStaticExecutable:
+               case Options::kObjectFile:
+               case Options::kPreload:
+                       fKeepDwarfUnwind = true;
+                       break;
+       }
+       
+}
+
+void Options::checkIllegalOptionCombinations()
+{
+       // check -undefined setting
        switch ( fUndefinedTreatment ) {
                case kUndefinedError:
                case kUndefinedDynamicLookup:
@@ -3177,6 +4128,7 @@ void Options::checkIllegalOptionCombinations()
                        if ( strcmp(&lastSlash[1], subUmbrella) == 0 ) {
                                info.options.fReExport = true;
                                found = true;
+                fLinkSnapshot.recordSubUmbrella(info.path);
                                break;
                        }
                }
@@ -3199,6 +4151,7 @@ void Options::checkIllegalOptionCombinations()
                        if ( strncmp(&lastSlash[1], subLibrary, dot-lastSlash-1) == 0 ) {
                                info.options.fReExport = true;
                                found = true;
+                fLinkSnapshot.recordSubLibrary(info.path);
                                break;
                        }
                }
@@ -3208,19 +4161,18 @@ void Options::checkIllegalOptionCombinations()
 
        // sync reader options
        if ( fNameSpace != kTwoLevelNameSpace )
-               fReaderOptions.fFlatNamespace = true;
+               fFlatNamespace = true;
 
        // check -stack_addr
        if ( fStackAddr != 0 ) {
                switch (fArchitecture) {
                        case CPU_TYPE_I386:
-                       case CPU_TYPE_POWERPC:
             case CPU_TYPE_ARM:
                                if ( fStackAddr > 0xFFFFFFFF )
                                        throw "-stack_addr must be < 4G for 32-bit processes";
                                break;
-                       case CPU_TYPE_POWERPC64:
                        case CPU_TYPE_X86_64:
+                       case CPU_TYPE_ARM64:
                                break;
                }
                if ( (fStackAddr & -4096) != fStackAddr )
@@ -3233,7 +4185,6 @@ void Options::checkIllegalOptionCombinations()
        if ( fStackSize != 0 ) {
                switch (fArchitecture) {
                        case CPU_TYPE_I386:
-                       case CPU_TYPE_POWERPC:
                                if ( fStackSize > 0xFFFFFFFF )
                                        throw "-stack_size must be < 4G for 32-bit processes";
                                if ( fStackAddr == 0 ) {
@@ -3249,12 +4200,19 @@ void Options::checkIllegalOptionCombinations()
                                        fStackAddr = 0x2F000000;
                 if ( fStackAddr > 0x30000000)
                     throw "-stack_addr must be < 0x30000000 for arm";
-                       case CPU_TYPE_POWERPC64:
+                               break;
                        case CPU_TYPE_X86_64:
                                if ( fStackAddr == 0 ) {
                                        fStackAddr = 0x00007FFF5C000000LL;
                                }
                                break;
+                       case CPU_TYPE_ARM64:
+                               if ( fStackSize > 0x20000000 )
+                                       throw "-stack_size must be < 512MB";
+                               if ( fStackAddr == 0 ) {
+                                       fStackAddr = 0x120000000;
+                               }
+                               break;
                }
                if ( (fStackSize & -4096) != fStackSize )
                        throw "-stack_size must be multiples of 4K";
@@ -3271,6 +4229,8 @@ void Options::checkIllegalOptionCombinations()
                        case Options::kKextBundle:
                                throw "-stack_size option can only be used when linking a main executable";
                }
+               if ( fStackSize > fStackAddr )
+                       throwf("-stack_size (0x%08llX) must be smaller than -stack_addr (0x%08llX)", fStackSize, fStackAddr);
        }
 
        // check that -allow_stack_execute is only used with main executables
@@ -3290,6 +4250,25 @@ void Options::checkIllegalOptionCombinations()
                }
        }
 
+       // check that -allow_heap_execute is only used with i386 main executables
+       if ( fDisableNonExecutableHeap ) {
+               if ( fArchitecture != CPU_TYPE_I386 )
+                       throw "-allow_heap_execute option can only be used when linking for i386";
+               switch ( fOutputKind ) {
+                       case Options::kDynamicExecutable:
+                               // -allow_heap_execute only legal when building main executable
+                               break;
+                       case Options::kStaticExecutable:
+                       case Options::kDynamicLibrary:
+                       case Options::kDynamicBundle:
+                       case Options::kObjectFile:
+                       case Options::kDyld:
+                       case Options::kPreload:
+                       case Options::kKextBundle:
+                               throw "-allow_heap_execute option can only be used when linking a main executable";
+               }
+       }
+
        // check -client_name is only used when making a bundle or main executable
        if ( fClientName != NULL ) {
                switch ( fOutputKind ) {
@@ -3319,58 +4298,104 @@ void Options::checkIllegalOptionCombinations()
                throw "-dtrace can only be used when creating final linked images";
 
        // check -d can only be used with -r
-       if ( fReaderOptions.fMakeTentativeDefinitionsReal && (fOutputKind != Options::kObjectFile) )
+       if ( fMakeTentativeDefinitionsReal && (fOutputKind != Options::kObjectFile) )
                throw "-d can only be used with -r";
 
        // check that -root_safe is not used with -r
-       if ( fReaderOptions.fRootSafe && (fOutputKind == Options::kObjectFile) )
+       if ( fRootSafe && (fOutputKind == Options::kObjectFile) )
                throw "-root_safe cannot be used with -r";
 
        // check that -setuid_safe is not used with -r
-       if ( fReaderOptions.fSetuidSafe && (fOutputKind == Options::kObjectFile) )
+       if ( fSetuidSafe && (fOutputKind == Options::kObjectFile) )
                throw "-setuid_safe cannot be used with -r";
 
+       // <rdar://problem/12781832> compiler driver no longer uses -objc_abi_version, it uses -ios_simulator_version_min instead
+       if ( !fObjCABIVersion1Override && !fObjCABIVersion2Override && fTargetIOSSimulator )
+               fObjCABIVersion2Override = true;
+
+       // rdar://problem/4718189 map ObjC class names to new runtime names
+       bool alterObjC1ClassNamesToObjC2 = false;
+       switch (fArchitecture) {
+               case CPU_TYPE_I386:
+                       // i386 only uses new symbols when using objc2 ABI
+                       if ( fObjCABIVersion2Override )
+                               alterObjC1ClassNamesToObjC2 = true;
+                       break;
+               case CPU_TYPE_X86_64:
+               case CPU_TYPE_ARM:
+               case CPU_TYPE_ARM64:
+                       alterObjC1ClassNamesToObjC2 = true;
+                       break;
+       }
+
        // make sure all required exported symbols exist
        std::vector<const char*> impliedExports;
-       for (NameSet::iterator it=fExportSymbols.regularBegin(); it != fExportSymbols.regularEnd(); it++) {
+       for (NameSet::iterator it=fExportSymbols.regularBegin(); it != fExportSymbols.regularEnd(); ++it) {
                const char* name = *it;
-               // never export .eh symbols
                const int len = strlen(name);
-               if ( (strcmp(&name[len-3], ".eh") == 0) || (strncmp(name, ".objc_category_name_", 20) == 0) ) 
+               if ( (strcmp(&name[len-3], ".eh") == 0) || (strncmp(name, ".objc_category_name_", 20) == 0) ) {
+                       // never export .eh symbols
                        warning("ignoring %s in export list", name);
-               else
+               }
+               else if ( (fArchitecture == CPU_TYPE_I386) && !fObjCABIVersion2Override && (strncmp(name, "_OBJC_CLASS_$", 13) == 0) ) {
+                       warning("ignoring Objc2 Class symbol %s in i386 export list", name);
+                       fRemovedExports.insert(name);
+               }
+               else if ( alterObjC1ClassNamesToObjC2 && (strncmp(name, ".objc_class_name_", 17) == 0) ) {
+                       // linking ObjC2 ABI, but have ObjC1 ABI name in export list.  Change it to intended name
+                       fRemovedExports.insert(name);
+                       char* temp;
+                       asprintf(&temp, "_OBJC_CLASS_$_%s", &name[17]);
+                       impliedExports.push_back(temp);
+                       asprintf(&temp, "_OBJC_METACLASS_$_%s", &name[17]);
+                       impliedExports.push_back(temp);
+               }
+               else {
                        fInitialUndefines.push_back(name);
-               if ( strncmp(name, ".objc_class_name_", 17) == 0 ) {
-                       // rdar://problem/4718189 map ObjC class names to new runtime names
-                       switch (fArchitecture) {
-                               case CPU_TYPE_POWERPC64:
-                               case CPU_TYPE_X86_64:
-                           case CPU_TYPE_ARM:
-                                       char* temp;
-                                       asprintf(&temp, "_OBJC_CLASS_$_%s", &name[17]);
-                                       impliedExports.push_back(temp);
-                                       asprintf(&temp, "_OBJC_METACLASS_$_%s", &name[17]);
-                                       impliedExports.push_back(temp);
-                                       break;
-                       }
                }
        }
-       for (std::vector<const char*>::iterator it=impliedExports.begin(); it != impliedExports.end(); it++) {
+       fExportSymbols.remove(fRemovedExports);
+       for (std::vector<const char*>::iterator it=impliedExports.begin(); it != impliedExports.end(); ++it) {
                const char* name = *it;
                fExportSymbols.insert(name);
                fInitialUndefines.push_back(name);
        }
 
-       // make sure that -init symbol exist
+       // make sure all required re-exported symbols exist
+       for (NameSet::iterator it=fReExportSymbols.regularBegin(); it != fReExportSymbols.regularEnd(); ++it) {
+               fInitialUndefines.push_back(*it);
+       }
+       
+       // make sure that -init symbol exists
        if ( fInitFunctionName != NULL )
                fInitialUndefines.push_back(fInitFunctionName);
 
+       // make sure that entry symbol exists
+       switch ( fOutputKind ) {
+               case Options::kDynamicExecutable:
+               case Options::kStaticExecutable:
+               case Options::kDyld:
+               case Options::kPreload:
+                       fInitialUndefines.push_back(fEntryName);
+                       break;
+               case Options::kDynamicLibrary:
+               case Options::kDynamicBundle:
+               case Options::kObjectFile:
+               case Options::kKextBundle:
+                       break;
+       }
+
+       // make sure every alias base exists
+       for (std::vector<AliasPair>::iterator it=fAliases.begin(); it != fAliases.end(); ++it) {
+               fInitialUndefines.push_back(it->realName);
+       }
+
        // check custom segments
        if ( fCustomSegmentAddresses.size() != 0 ) {
                // verify no segment is in zero page
                if ( fZeroPageSize != ULLONG_MAX ) {
                        for (std::vector<SegmentStart>::iterator it = fCustomSegmentAddresses.begin(); it != fCustomSegmentAddresses.end(); ++it) {
-                               if ( (it->address >= 0) && (it->address < fZeroPageSize) )
+                               if ( it->address < fZeroPageSize )
                                        throwf("-segaddr %s 0x%llX conflicts with -pagezero_size", it->name, it->address);
                        }
                }
@@ -3390,18 +4415,11 @@ void Options::checkIllegalOptionCombinations()
                // zero page size not specified on command line, set default
                switch (fArchitecture) {
                        case CPU_TYPE_I386:
-                       case CPU_TYPE_POWERPC:
             case CPU_TYPE_ARM:
                                // first 4KB for 32-bit architectures
                                fZeroPageSize = 0x1000;
                                break;
-                       case CPU_TYPE_POWERPC64:
-                               // first 4GB for ppc64 on 10.5
-                               if ( fReaderOptions.fMacVersionMin >= ObjectFile::ReaderOptions::k10_5 )
-                                       fZeroPageSize = 0x100000000ULL;
-                               else
-                                       fZeroPageSize = 0x1000; // 10.4 dyld may not be able to handle >4GB zero page
-                               break;
+                       case CPU_TYPE_ARM64:
                        case CPU_TYPE_X86_64:
                                // first 4GB for x86_64 on all OS's
                                fZeroPageSize = 0x100000000ULL;
@@ -3428,13 +4446,21 @@ void Options::checkIllegalOptionCombinations()
                }
        }
 
+       // if main executable with custom base address, model zero page as custom segment
+       if ( (fOutputKind == Options::kDynamicExecutable) && (fBaseAddress != 0) && (fZeroPageSize != 0) ) {
+               SegmentStart seg;
+               seg.name = "__PAGEZERO";
+               seg.address = 0;;
+               fCustomSegmentAddresses.push_back(seg);
+       }
+
        // -dead_strip and -r are incompatible
-       if ( (fDeadStrip != kDeadStripOff) && (fOutputKind == Options::kObjectFile) )
+       if ( fDeadStrip && (fOutputKind == Options::kObjectFile) )
                throw "-r and -dead_strip cannot be used together";
 
        // can't use -rpath unless targeting 10.5 or later
        if ( fRPaths.size() > 0 ) {
-               if ( !minOS(ObjectFile::ReaderOptions::k10_5, ObjectFile::ReaderOptions::k2_0) )
+               if ( !minOS(ld::mac10_5, ld::iOS_2_0) )
                        throw "-rpath can only be used when targeting Mac OS X 10.5 or later";
                switch ( fOutputKind ) {
                        case Options::kDynamicExecutable:
@@ -3450,24 +4476,31 @@ void Options::checkIllegalOptionCombinations()
                }
        }
        
-       // check -pie is only used when building a dynamic main executable for 10.5
        if ( fPositionIndependentExecutable ) {
                switch ( fOutputKind ) {
                        case Options::kDynamicExecutable:
+                               // check -pie is only used when building a dynamic main executable for 10.5
+                               if ( !minOS(ld::mac10_5, ld::iOS_4_2) ) {
+                                       if ( fIOSVersionMin == ld::iOSVersionUnset )
+                                               throw "-pie can only be used when targeting Mac OS X 10.5 or later";
+                                       else
+                                               throw "-pie can only be used when targeting iOS 4.2 or later";
+                               }
+                               break;
+                       case Options::kStaticExecutable:
                        case Options::kPreload:
+                               // -pie is ok with -static or -preload
                                break;
                        case Options::kDynamicLibrary:
                        case Options::kDynamicBundle:
                                warning("-pie being ignored. It is only used when linking a main executable");
+                               fPositionIndependentExecutable = false;
                                break;
-                       case Options::kStaticExecutable:
                        case Options::kObjectFile:
                        case Options::kDyld:
                        case Options::kKextBundle:
                                throw "-pie can only be used when linking a main executable";
                }
-               if ( !minOS(ObjectFile::ReaderOptions::k10_5, ObjectFile::ReaderOptions::k2_0) )
-                       throw "-pie can only be used when targeting Mac OS X 10.5 or later";
        }
        
        // check -read_only_relocs is not used with x86_64
@@ -3492,6 +4525,22 @@ void Options::checkIllegalOptionCombinations()
                        warning("-force_cpusubtype_ALL will become unsupported for ARM architectures");
                }
        }
+       
+       // -reexported_symbols_list can only be used with -dynamiclib
+       if ( !fReExportSymbols.empty() ) {
+               if ( fOutputKind != Options::kDynamicLibrary )
+                       throw "-reexported_symbols_list can only used used when created dynamic libraries";
+               if ( !minOS(ld::mac10_7, ld::iOS_4_2) )
+                       throw "targeted OS version does not support -reexported_symbols_list";
+       }
+       
+       // -dyld_env can only be used with main executables
+       if ( (fOutputKind != Options::kDynamicExecutable) && (fDyldEnvironExtras.size() != 0) )
+               throw "-dyld_env can only used used when created main executables";
+
+       // -rename_sections can only be used in -r mode
+       if ( (fSectionRenames.size() != 0) && (fOutputKind != Options::kObjectFile) )
+               throw "-rename_sections can only used used in -r mode";
 }      
 
 
@@ -3507,9 +4556,23 @@ void Options::checkForClassic(int argc, const char* argv[])
        bool newLinker = false;
        
        // build command line buffer in case ld crashes
+#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 1070
+       CRSetCrashLogMessage(crashreporterBuffer);
+#endif
+       const char* srcRoot = getenv("SRCROOT");
+       if ( srcRoot != NULL ) {
+               strlcpy(crashreporterBuffer, "SRCROOT=", crashreporterBufferSize);
+               strlcat(crashreporterBuffer, srcRoot, crashreporterBufferSize);
+               strlcat(crashreporterBuffer, "\n", crashreporterBufferSize);
+       }
+#ifdef LD_VERS
+       strlcat(crashreporterBuffer, LD_VERS, crashreporterBufferSize);
+       strlcat(crashreporterBuffer, "\n", crashreporterBufferSize);
+#endif
+       strlcat(crashreporterBuffer, "ld ", crashreporterBufferSize);
        for(int i=1; i < argc; ++i) {
-               strlcat(crashreporterBuffer, argv[i], 1000);
-               strlcat(crashreporterBuffer, " ", 1000);
+               strlcat(crashreporterBuffer, argv[i], crashreporterBufferSize);
+               strlcat(crashreporterBuffer, " ", crashreporterBufferSize);
        }
 
        for(int i=0; i < argc; ++i) {
@@ -3538,6 +4601,7 @@ void Options::checkForClassic(int argc, const char* argv[])
                                // ld_classic does not understand this option, so remove it
                                for(int j=i; j < argc; ++j)
                                        argv[j] = argv[j+1];
+                               warning("using ld_classic");
                                this->gotoClassicLinker(argc-1, argv);
                        }
                        else if ( strcmp(arg, "-o") == 0 ) {
@@ -3547,55 +4611,41 @@ void Options::checkForClassic(int argc, const char* argv[])
                        }
                }
        }
-       
-       // -dtrace only supported by new linker
-       if( dtraceFound )
-               return;
-
-       if( archFound ) {
-               switch ( fArchitecture ) {
-               case CPU_TYPE_POWERPC:
-               case CPU_TYPE_I386:
-        case CPU_TYPE_ARM:
-//                     if ( staticFound && (rFound || !creatingMachKernel) ) {
-                       if ( (staticFound || kextFound) && !newLinker ) {
-                               // this environment variable will disable use of ld_classic for -static links
-                               if ( getenv("LD_NO_CLASSIC_LINKER_STATIC") == NULL ) {
-                                       // ld_classic does not support -iphoneos_version_min, so change
-                                       for(int j=0; j < argc; ++j) {
-                                               if ( strcmp(argv[j], "-iphoneos_version_min") == 0) {
-                                                       argv[j] = "-macosx_version_min";
-                                                       if ( j < argc-1 )
-                                                               argv[j+1] = "10.5";
-                                                       break;
-                                               }
-                                       }
-                                       // ld classic does not understand -kext (change to -static -r)
-                                       if ( kextFound ) {
-                                               for(int j=0; j < argc; ++j) {
-                                                       if ( strcmp(argv[j], "-kext") == 0) 
-                                                               argv[j] = "-r";
-                                                       else if ( strcmp(argv[j], "-dynamic") == 0) 
-                                                               argv[j] = "-static";
-                                               }
-                                       }
-                                       this->gotoClassicLinker(argc, argv);
-                               }
-                       }
-                       break;
-               }
-       }
-       else {
-               // work around for VSPTool
-               if ( staticFound )
-                       this->gotoClassicLinker(argc, argv);
-       }
-
 }
 
 void Options::gotoClassicLinker(int argc, const char* argv[])
 {
        argv[0] = "ld_classic";
+       // ld_classic does not support -iphoneos_version_min, so change
+       for(int j=0; j < argc; ++j) {
+               if ( (strcmp(argv[j], "-iphoneos_version_min") == 0) || (strcmp(argv[j], "-ios_version_min") == 0) ) {
+                       argv[j] = "-macosx_version_min";
+                       if ( j < argc-1 )
+                               argv[j+1] = "10.5";
+                       break;
+               }
+       }
+       // ld classic does not understand -kext (change to -static -r)
+       for(int j=0; j < argc; ++j) {
+               if ( strcmp(argv[j], "-kext") == 0) 
+                       argv[j] = "-r";
+               else if ( strcmp(argv[j], "-dynamic") == 0) 
+                       argv[j] = "-static";
+       }
+       // ld classic does not understand -demangle 
+       for(int j=0; j < argc; ++j) {
+               if ( strcmp(argv[j], "-demangle") == 0) 
+                       argv[j] = "-noprebind";
+       }
+       // in -v mode, print command line passed to ld_classic
+       for(int i=0; i < argc; ++i) {
+               if ( strcmp(argv[i], "-v") == 0 ) {
+                       for(int j=0; j < argc; ++j)
+                               printf("%s ", argv[j]);
+                       printf("\n");
+                       break;
+               }
+       }
        char rawPath[PATH_MAX];
        char path[PATH_MAX];
        uint32_t bufSize = PATH_MAX;
@@ -3614,3 +4664,70 @@ void Options::gotoClassicLinker(int argc, const char* argv[])
        fprintf(stderr, "can't exec ld_classic\n");
        exit(1);
 }
+
+
+// Note, returned string buffer is own by this function.
+// It should not be freed
+// It will be reused, so clients need to strdup() if they want
+// to use it long term.
+const char* Options::demangleSymbol(const char* sym) const
+{
+       // only try to demangle symbols if -demangle on command line
+       if ( !fDemangle )
+               return sym;
+
+       // only try to demangle symbols that look like C++ symbols
+       if ( strncmp(sym, "__Z", 3) != 0 )
+               return sym;
+
+       static size_t size = 1024;
+       static char* buff = (char*)malloc(size);
+       int status;
+       
+       char* result = abi::__cxa_demangle(&sym[1], buff, &size, &status); 
+       if ( result != NULL ) {
+               // if demangling successful, keep buffer for next demangle
+               buff = result;
+               return buff;
+       }
+       return sym;
+}
+
+
+void Options::dumpDependency(uint8_t opcode, const char* path) const
+{
+       if ( !this->dumpDependencyInfo() ) 
+               return;
+
+       // one time open() of -dependency_info file
+       if ( fDependencyFileDescriptor == -1 ) {
+               fDependencyFileDescriptor = open(this->dependencyInfoPath(), O_WRONLY | O_TRUNC | O_CREAT, 0666);
+               if ( fDependencyFileDescriptor == -1 )
+                       throwf("Could not open or create -dependency_info file: %s", this->dependencyInfoPath());
+
+               // write header
+               uint8_t version = depLinkerVersion;
+               if ( write(fDependencyFileDescriptor, &version, 1) == -1 )
+                       throwf("write() to -dependency_info failed, errno=%d", errno);
+               extern const char ldVersionString[];
+               if ( write(fDependencyFileDescriptor, ldVersionString, strlen(ldVersionString)+1) == -1 )
+                       throwf("write() to -dependency_info failed, errno=%d", errno);
+       }
+
+       char realPath[PATH_MAX];
+       if ( path[0] != '/' ) {
+               if ( realpath(path, realPath) != NULL ) {
+                       path = realPath;
+               }
+       }
+
+       if ( write(fDependencyFileDescriptor, &opcode, 1) == -1 )
+               throwf("write() to -dependency_info failed, errno=%d", errno);
+       if ( write(fDependencyFileDescriptor, path, strlen(path)+1) == -1 )
+               throwf("write() to -dependency_info failed, errno=%d", errno);
+
+       //fprintf(stderr, "0x%02X %s\n", opcode, path);
+}
+
+
+