]> git.saurik.com Git - apple/ld64.git/blobdiff - src/ld/Options.cpp
ld64-128.2.tar.gz
[apple/ld64.git] / src / ld / Options.cpp
index 6521abebcbf98a7aefe658b35303f0844417ab9e..629903f89a082f5b3cc51e1c726156da9f1f0a99 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@
  *
@@ -28,6 +28,7 @@
 #include <mach/vm_prot.h>
 #include <mach-o/dyld.h>
 #include <fcntl.h>
+
 #include <vector>
 
 #include "configure.h"
 #include "Architectures.hpp"
 #include "MachOFileAbstraction.hpp"
 
-extern void printLTOVersion(Options &opts);
+// upward dependency on lto::version()
+namespace lto {
+       extern const char* version();
+}
 
 // magic to place command line in crash reports
+const int crashreporterBufferSize = 2000;
 extern "C" char* __crashreporter_info__;
-static char crashreporterBuffer[1000];
+static char crashreporterBuffer[crashreporterBufferSize];
 char* __crashreporter_info__ = crashreporterBuffer;
 
 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 ) {
@@ -81,30 +89,52 @@ void throwf(const char* format, ...)
 }
 
 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), 
+         fDyldInstallPath("/usr/lib/dyld"), fTempLtoObjectPath(NULL), 
          fZeroPageSize(ULLONG_MAX), fStackSize(0), fStackAddr(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),
+         fReadOnlyx86Stubs(false), fPositionIndependentExecutable(false), fPIEOnCommandLine(false),
+         fDisablePositionIndependentExecutable(false), fMaxMinimumHeaderPad(false),
          fDeadStripDylibs(false),  fAllowTextRelocs(false), fWarnTextRelocs(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),
+         fCanReExportSymbols(false), fObjcCategoryMerging(true), fPageAlignDataAtoms(false), 
+         fDebugInfoStripping(kDebugInfoMinimal), fTraceOutputFile(NULL), 
+         fMacVersionMin(ld::macVersionUnset), fIOSVersionMin(ld::iOSVersionUnset), 
+         fSaveTempFiles(false)
 {
        this->checkForClassic(argc, argv);
        this->parsePreCommandLineEnvironmentSettings();
@@ -118,48 +148,14 @@ Options::~Options()
 {
 }
 
-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 +165,8 @@ 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 +179,32 @@ 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 )
@@ -343,59 +226,122 @@ 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
+       if ( fIOSVersionMin != ld::iOSVersionUnset ) 
+               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;
@@ -477,8 +423,28 @@ 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::shouldExport(const char* symbolName)
+
+bool Options::shouldExport(const char* symbolName) const
 {
        switch (fExportMode) {
                case kExportSome:
@@ -491,7 +457,12 @@ 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:
@@ -506,81 +477,102 @@ 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 )
-               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;
+       fArchitecture = type;
+       fSubArchitecture = subtype;
+       switch ( type ) {
+       case CPU_TYPE_I386:
+               fArchitectureName = "i386";
+               if ( (fMacVersionMin == ld::macVersionUnset) && (fOutputKind != Options::kObjectFile) ) {
+       #ifdef DEFAULT_MACOSX_MIN_VERSION
+                       warning("-macosx_version_min not specificed, assuming " DEFAULT_MACOSX_MIN_VERSION);
+                       setMacOSXVersionMin(DEFAULT_MACOSX_MIN_VERSION);
+       #else
+                       warning("-macosx_version_min not specificed, assuming 10.6");
+                       fMacVersionMin = ld::mac10_6;
+       #endif          
+               }
+               if ( !fMakeCompressedDyldInfo && (fMacVersionMin >= ld::mac10_6) && !fMakeCompressedDyldInfoForceOff )
+                       fMakeCompressedDyldInfo = true;
+               break;
+       case CPU_TYPE_X86_64:
+               fArchitectureName = "x86_64";
+               if ( (fMacVersionMin == ld::macVersionUnset) && (fOutputKind != Options::kObjectFile) ) {
+       #ifdef DEFAULT_MACOSX_MIN_VERSION
+                       warning("-macosx_version_min not specificed, assuming " DEFAULT_MACOSX_MIN_VERSION);
+                       setMacOSXVersionMin(DEFAULT_MACOSX_MIN_VERSION);
+       #else
+                       warning("-macosx_version_min not specificed, assuming 10.6");
+                       fMacVersionMin = ld::mac10_6;
+       #endif          
+               }
+               if ( !fMakeCompressedDyldInfo && (fMacVersionMin >= ld::mac10_6) && !fMakeCompressedDyldInfoForceOff )
+                       fMakeCompressedDyldInfo = true;
+               break;
+       case CPU_TYPE_ARM:
+               fHasPreferredSubType = true;
+               for (const ARMSubType* t=ARMSubTypes; t->subTypeName != NULL; ++t) {
+                       if ( t->subType == subtype ) {
+                               fArchitectureName = t->subTypeName;
+                               fArchSupportsThumb2 = t->supportsThumb2;
+                               break;
+                       }
+               }
+               assert(fArchitectureName != NULL);
+               if ( (fMacVersionMin == ld::macVersionUnset) && (fIOSVersionMin == ld::iOSVersionUnset) && (fOutputKind != Options::kObjectFile) ) {
+#if defined(DEFAULT_IPHONEOS_MIN_VERSION)
+                       warning("-ios_version_min not specificed, assuming " DEFAULT_IPHONEOS_MIN_VERSION);
+                       setIOSVersionMin(DEFAULT_IPHONEOS_MIN_VERSION);
+#elif defined(DEFAULT_MACOSX_MIN_VERSION)
+                       warning("-macosx_version_min not specificed, assuming " DEFAULT_MACOSX_MIN_VERSION);
+                       setMacOSXVersionMin(DEFAULT_MACOSX_MIN_VERSION);
+#else
+                       warning("-macosx_version_min not specificed, assuming 10.6");
+                       fMacVersionMin = ld::mac10_6;
+#endif
+               }
+               if ( !fMakeCompressedDyldInfo && minOS(ld::mac10_6, ld::iOS_3_1) && !fMakeCompressedDyldInfoForceOff )
+                       fMakeCompressedDyldInfo = true;
+               break;
+       default:
+               fArchitectureName = "unknown architecture";
+               break;
        }
-       else if ( strcmp(architecture, "i386") == 0 ) {
+}
+
+void Options::parseArch(const char* arch)
+{
+       if ( arch == NULL )
+               throw "-arch must be followed by an architecture string";
+       fArchitectureName = arch;
+       if ( strcmp(arch, "i386") == 0 ) {
                fArchitecture = CPU_TYPE_I386;
                fSubArchitecture = CPU_SUBTYPE_I386_ALL;
        }
-       else if ( strcmp(architecture, "x86_64") == 0 ) {
+       else if ( strcmp(arch, "x86_64") == 0 ) {
                fArchitecture = CPU_TYPE_X86_64;
                fSubArchitecture = CPU_SUBTYPE_X86_64_ALL;
        }
-       else if ( strcmp(architecture, "arm") == 0 ) {
+       else if ( strcmp(arch, "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;
+       else {
+               for (const ARMSubType* t=ARMSubTypes; t->subTypeName != NULL; ++t) {
+                       if ( strcmp(t->subTypeName,arch) == 0 ) {
+                               fArchitecture = CPU_TYPE_ARM;
+                               fSubArchitecture = t->subType;
+                               fArchSupportsThumb2 = t->supportsThumb2;
+                               fHasPreferredSubType = true;
+                               return;
+                       }
+               }
+               throwf("unknown/unsupported architecture name for: -arch %s", arch);
        }
-       else
-               throwf("unknown/unsupported architecture name for: -arch %s", architecture);
 }
 
-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];
@@ -722,7 +714,7 @@ 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;
@@ -730,7 +722,7 @@ Options::FileInfo Options::findFile(const char* path)
        // 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);
@@ -776,7 +768,7 @@ 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 +794,7 @@ 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 +817,7 @@ 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;
@@ -841,7 +833,7 @@ Options::FileInfo Options::findFileUsingPaths(const char* 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 +870,7 @@ 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;
@@ -938,7 +930,18 @@ void Options::loadFileList(const char* fileOfPaths)
        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 +955,28 @@ 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 +1005,7 @@ 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 +1040,8 @@ 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 )
@@ -1116,7 +1128,7 @@ void Options::parseAliasFile(const char* fileOfAliases)
        ::close(fd);
 
        // 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 +1174,7 @@ 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 +1185,7 @@ void Options::parseAliasFile(const char* fileOfAliases)
                                        *last = '\0';
                                        --last;
                                }
-                               fReaderOptions.fAliases.push_back(pair);
+                               fAliases.push_back(pair);
                                state = lineStart;
                        }
                        break;
@@ -1227,69 +1239,37 @@ 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 = version[3] - '0';
+               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 +1352,67 @@ 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 +1422,7 @@ 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 +1509,7 @@ 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);
@@ -1519,18 +1550,12 @@ 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 )
@@ -1711,6 +1736,8 @@ void Options::parse(int argc, const char* argv[])
                                fprintf (stderr, "[Logging ld64 options]\t%s\n", arg);
 
                        if ( (arg[1] == 'L') || (arg[1] == 'F') ) {
+                               if (arg[2] == '\0')
+                                       ++i;
                                // previously handled by buildSearchPaths()
                        }
                        // The one gnu style option we have to keep compatibility
@@ -1727,8 +1754,8 @@ 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;
                                }
                        }
@@ -1757,6 +1784,12 @@ void Options::parse(int argc, const char* argv[])
                        else if ( strcmp(arg, "-o") == 0 ) {
                                fOutputFile = argv[++i];
                        }
+                       else if ( strncmp(arg, "-lazy-l", 7) == 0 ) {
+                               FileInfo info = findLibrary(&arg[7], true);
+                               info.options.fLazyLoad = true;
+                               addLibrary(info);
+                               fUsingLazyDylibLinking = true;
+                       }
                        else if ( (arg[1] == 'l') && (strncmp(arg,"-lazy_",6) !=0) ) {
                                addLibrary(findLibrary(&arg[2]));
                        }
@@ -1767,14 +1800,7 @@ void Options::parse(int argc, const char* argv[])
                                info.options.fWeakImport = true;
                                addLibrary(info);
                        }
-                       else if ( strncmp(arg, "-lazy-l", 7) == 0 ) {
-                               FileInfo info = findLibrary(&arg[7], true);
-                               info.options.fLazyLoad = true;
-                               addLibrary(info);
-                               fUsingLazyDylibLinking = true;
-                       }
                        // Avoid lazy binding.
-                       // ??? Deprecate.
                        else if ( strcmp(arg, "-bind_at_load") == 0 ) {
                                fBindAtLoad = true;
                        }
@@ -1792,14 +1818,14 @@ 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 ) {
@@ -1813,14 +1839,14 @@ 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) )
@@ -1940,7 +1966,8 @@ 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 ) {
@@ -1971,6 +1998,9 @@ void Options::parse(int argc, const char* argv[])
                        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]);
                        }
@@ -2076,9 +2106,9 @@ 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.
@@ -2138,6 +2168,9 @@ 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>";
@@ -2169,8 +2202,11 @@ void Options::parse(int argc, const char* argv[])
                        else if ( strcmp(arg, "-macosx_version_min") == 0 ) {
                                setMacOSXVersionMin(argv[++i]);
                        }
-                       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]);
                        }
                        else if ( strcmp(arg, "-multiply_defined") == 0 ) {
                                //warnObsolete(arg);
@@ -2199,7 +2235,7 @@ 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 +2258,43 @@ 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 +2311,10 @@ 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 +2385,7 @@ 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()
@@ -2371,20 +2410,20 @@ void Options::parse(int argc, const char* argv[])
                                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 ) {
                                parseAliasFile(argv[++i]);
@@ -2394,12 +2433,12 @@ void Options::parse(int argc, const char* argv[])
                                const char* colon = strchr(arg, ':');
                                if ( colon == NULL )
                                        throwf("unknown option: %s", arg);
-                               ObjectFile::ReaderOptions::AliasPair pair;
+                               Options::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);
+                               fAliases.push_back(pair);
                        }
                        else if ( strcmp(arg, "-save-temps") == 0 ) {
                                fSaveTempFiles = true;
@@ -2423,6 +2462,10 @@ 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 ) {
                                FileInfo info = findLibrary(&arg[11], true);
@@ -2439,11 +2482,26 @@ void Options::parse(int argc, const char* argv[])
                                info.options.fReExport = true;
                                addLibrary(info);
                        }
-                       else if ( strcmp(arg, "-dead_strip_dylibs") == 0 ) {
-                               fDeadStripDylibs = true;
+                       else if ( strncmp(arg, "-upward-l", 9) == 0 ) {
+                               FileInfo info = findLibrary(&arg[9], true);
+                               info.options.fUpward = true;
+                               addLibrary(info);
+                       }
+                       else if ( strcmp(arg, "-upward_library") == 0 ) {
+                               FileInfo info = findFile(argv[++i]);
+                               info.options.fUpward = true;
+                               addLibrary(info);
+                       }
+                       else if ( strcmp(arg, "-upward_framework") == 0 ) {
+                               FileInfo info = findFramework(argv[++i]);
+                               info.options.fUpward = true;
+                               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 +2510,7 @@ 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];
@@ -2461,7 +2519,7 @@ void Options::parse(int argc, const char* argv[])
                                fLLVMOptions.push_back(opts);
                        }
                        else if ( strcmp(arg, "-no_order_inits") == 0 ) {
-                               fReaderOptions.fAutoOrderInitializers = false;
+                               fAutoOrderInitializers = false;
                        }
                        else if ( strcmp(arg, "-no_order_data") == 0 ) {
                                fOrderData = false;
@@ -2484,19 +2542,118 @@ void Options::parse(int argc, const char* argv[])
                                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, "-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 ) {
+                               loadExportFile(argv[++i], "-force_symbols_weak_list", fForceWeakSymbols);
+                       }
+                       else if ( strcmp(arg, "-force_symbols_not_weak_list") == 0 ) {
+                               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 ) {
+                               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 {
                                throwf("unknown option: %s", arg);
@@ -2537,10 +2694,52 @@ 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 ) {
@@ -2549,9 +2748,9 @@ void Options::buildSearchPaths(int argc, const char* argv[])
                        fprintf(stderr, "%s", ldVersionString);
                         // 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, "%s\n", ltoVers);
                                exit(0);
                        }
                }
@@ -2562,12 +2761,17 @@ 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;
+               }
        }
        int standardLibraryPathsStartIndex = libraryPaths.size();
        int standardFrameworkPathsStartIndex = frameworkPaths.size();
@@ -2685,12 +2889,12 @@ 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 +2904,8 @@ 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 +2919,11 @@ 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;
 }
 
 
@@ -2743,13 +2945,13 @@ 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:
@@ -2772,48 +2974,75 @@ 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 specificed, assuming " DEFAULT_MACOSX_MIN_VERSION);
+                                               setMacOSXVersionMin(DEFAULT_MACOSX_MIN_VERSION);
+                       #else
+                                               warning("-macosx_version_min not specificed, 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 specificed, assuming " DEFAULT_IPHONEOS_MIN_VERSION);
+                                               setIOSVersionMin(DEFAULT_IPHONEOS_MIN_VERSION);
+                       #elif defined(DEFAULT_MACOSX_MIN_VERSION)
+                                               warning("-macosx_version_min not specificed, assuming " DEFAULT_MACOSX_MIN_VERSION);
+                                               setMacOSXVersionMin(DEFAULT_MACOSX_MIN_VERSION);
+                       #else
+                                               warning("-macosx_version_min not specificed, assuming 10.6");
+                                               fMacVersionMin = ld::mac10_6;
+                       #endif
+                                       }
+                                       break;
+                               default:
+                                       // architecture will be infered ;ater by examining .o files
                                        break;
                        }
                }
@@ -2823,21 +3052,15 @@ 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 ) {
                                //warning("-macosx_version_min should be 10.4 or later for x86_64");
-                               fReaderOptions.fMacVersionMin = ObjectFile::ReaderOptions::k10_4;
+                               fMacVersionMin = ld::mac10_4;
                        }
                        break;
        }
@@ -2847,14 +3070,22 @@ void Options::reconfigureDefaults()
                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_ARM:
+                               if ( fIOSVersionMin >= ld::iOS_5_0 ) {
+                    // iOS 5.0 and later use new MH_KEXT_BUNDLE type
+                    fMakeCompressedDyldInfo = false;
+                    fMakeCompressedDyldInfoForceOff = true;
+                    fAllowTextRelocs = true;
+                    fUndefinedTreatment = kUndefinedDynamicLookup;
+                                       break;
+                               }
+                               // else use object file
+                       case CPU_TYPE_I386:
                                // use .o files
                                fOutputKind = kObjectFile;
                                break;
@@ -2863,8 +3094,8 @@ 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 +3127,8 @@ 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 +3153,37 @@ 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 +3191,20 @@ 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 +3224,6 @@ void Options::reconfigureDefaults()
                                        }
                                }
                                break;
-                       case CPU_TYPE_POWERPC64:
                        case CPU_TYPE_X86_64:
                                fPrebind = false;
                                break;
@@ -2990,21 +3253,23 @@ 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
@@ -3014,7 +3279,7 @@ void Options::reconfigureDefaults()
        
        // <rdar://problem/5366363> -r -x implies -S
        if ( (fOutputKind == Options::kObjectFile) && (fLocalSymbolHandling == kLocalSymbolsNone) )
-               fReaderOptions.fDebugInfoStripping = ObjectFile::ReaderOptions::kDebugInfoNone;                 
+               fDebugInfoStripping = Options::kDebugInfoNone;                  
                
        // choose how to process unwind info
        switch ( fArchitecture ) {
@@ -3025,26 +3290,24 @@ void Options::reconfigureDefaults()
                                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;
        }
                
@@ -3057,7 +3320,7 @@ void Options::reconfigureDefaults()
        // 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
@@ -3075,49 +3338,45 @@ 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
        if ( fMakeCompressedDyldInfo ) {
                switch (fArchitecture) {
                        case CPU_TYPE_I386:
+                               if ( fIOSVersionMin != ld::iOSVersionUnset ) // simulator always uses compressed LINKEDIT
+                                       break;
                        case CPU_TYPE_X86_64:
-                               if ( fReaderOptions.fMacVersionMin >= ObjectFile::ReaderOptions::k10_6 ) 
-                                       fMakeClassicDyldInfo = false; 
-                               else if ( fReaderOptions.fMacVersionMin < ObjectFile::ReaderOptions::k10_5 )
+                               if ( fMacVersionMin < ld::mac10_6 ) 
                                        fMakeCompressedDyldInfo = false;
                                break;
             case CPU_TYPE_ARM:
-                               if ( fReaderOptions.fIPhoneVersionMin >= ObjectFile::ReaderOptions::k3_1 ) 
-                                       fMakeClassicDyldInfo = false; 
-                               else if ( fReaderOptions.fIPhoneVersionMin < ObjectFile::ReaderOptions::k3_1 )
+                               if ( !minOS(ld::mac10_6, ld::iOS_3_1) )
                                        fMakeCompressedDyldInfo = false;
                                break;
-                       case CPU_TYPE_POWERPC:
-                       case CPU_TYPE_POWERPC64:
                        default:
                                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;
-               }
-       }
-       fReaderOptions.fMakeCompressedDyldInfo = fMakeCompressedDyldInfo;
                
        // only ARM enforces that cpu-sub-types must match
        if ( fArchitecture != CPU_TYPE_ARM )
@@ -3125,7 +3384,11 @@ void Options::reconfigureDefaults()
                
        // 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 ) {
@@ -3145,8 +3408,128 @@ 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;
+       }
+
+       // 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;
+
+       // set fOutputSlidable
+       switch ( fOutputKind ) {
+               case Options::kObjectFile:
+               case Options::kStaticExecutable:
+                       fOutputSlidable = false;
+                       break;
+               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;
+       }
+       
+       // 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;
+                       // <rdar://problem/9945513> for now, don't create version load commands for iOS simulator builds
+                       if ( fVersionLoadCommand && (fArchitecture == CPU_TYPE_I386) ) {
+                               for (std::vector<const char*>::iterator sdkit = fSDKPaths.begin(); sdkit != fSDKPaths.end(); sdkit++) {
+                                       if ( strstr(*sdkit, "/iPhoneSimulator.platform/") != NULL )
+                                               fVersionLoadCommand = false;
+                               }
+                       }
+                       break;
+       }
+       
+       // default to adding functions start for dynamic code, static code must opt-in
+       switch ( fOutputKind ) {
+               case Options::kObjectFile:
+                       fFunctionStartsLoadCommand = false;
+                       break;
+               case Options::kPreload:
+               case Options::kStaticExecutable:
+               case Options::kKextBundle:
+                       if ( fFunctionStartsForcedOn )
+                               fFunctionStartsLoadCommand = true;
+                       break;
+               case Options::kDynamicExecutable:
+               case Options::kDyld:
+               case Options::kDynamicLibrary:
+               case Options::kDynamicBundle:
+                       if ( !fFunctionStartsForcedOff )
+                               fFunctionStartsLoadCommand = 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;
 }
 
 void Options::checkIllegalOptionCombinations()
@@ -3208,18 +3591,16 @@ 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:
                                break;
                }
@@ -3233,7 +3614,6 @@ 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 ) {
@@ -3249,7 +3629,6 @@ void Options::checkIllegalOptionCombinations()
                                        fStackAddr = 0x2F000000;
                 if ( fStackAddr > 0x30000000)
                     throw "-stack_addr must be < 0x30000000 for arm";
-                       case CPU_TYPE_POWERPC64:
                        case CPU_TYPE_X86_64:
                                if ( fStackAddr == 0 ) {
                                        fStackAddr = 0x00007FFF5C000000LL;
@@ -3271,6 +3650,8 @@ 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 +3671,25 @@ 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 +3719,99 @@ 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/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:
+                       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 +3831,10 @@ 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_X86_64:
                                // first 4GB for x86_64 on all OS's
                                fZeroPageSize = 0x100000000ULL;
@@ -3428,13 +3861,21 @@ 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:
@@ -3454,11 +3895,19 @@ void Options::checkIllegalOptionCombinations()
        if ( fPositionIndependentExecutable ) {
                switch ( fOutputKind ) {
                        case Options::kDynamicExecutable:
+                               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::kPreload:
                                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:
@@ -3466,8 +3915,6 @@ void Options::checkIllegalOptionCombinations()
                        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 +3939,18 @@ 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";
 }      
 
 
@@ -3507,9 +3966,20 @@ void Options::checkForClassic(int argc, const char* argv[])
        bool newLinker = false;
        
        // build command line buffer in case ld crashes
+       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 +4008,7 @@ 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 ) {
@@ -3547,38 +4018,17 @@ 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);
                                }
                        }
@@ -3587,8 +4037,10 @@ void Options::checkForClassic(int argc, const char* argv[])
        }
        else {
                // work around for VSPTool
-               if ( staticFound )
+               if ( staticFound ) {
+                       warning("using ld_classic");
                        this->gotoClassicLinker(argc, argv);
+               }
        }
 
 }
@@ -3596,6 +4048,36 @@ void Options::checkForClassic(int argc, const char* 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;