]> git.saurik.com Git - apple/ld64.git/blobdiff - src/ld/ld.cpp
ld64-128.2.tar.gz
[apple/ld64.git] / src / ld / ld.cpp
index ded2a19adfda871053e788abd05cfd1ccd2f1c50..ce49e73463db5ed6418b2d23a0b0bf7c207ccbca 100644 (file)
@@ -1,5 +1,6 @@
 /* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-*
- * Copyright (c) 2005-2009 Apple Inc. All rights reserved.
+ *
+ * Copyright (c) 2005-2011 Apple Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
  *
@@ -23,7 +24,7 @@
  
 // start temp HACK for cross builds
 extern "C" double log2 ( double );
-#define __MATH__
+//#define __MATH__
 // end temp HACK for cross builds
 
 
@@ -36,11 +37,15 @@ extern "C" double log2 ( double );
 #include <errno.h>
 #include <limits.h>
 #include <unistd.h>
+#include <execinfo.h>
 #include <mach/mach_time.h>
 #include <mach/vm_statistics.h>
 #include <mach/mach_init.h>
 #include <mach/mach_host.h>
 #include <dlfcn.h>
+#include <mach-o/dyld.h>
+#include <dlfcn.h>
+#include <AvailabilityMacros.h>
 
 #include <string>
 #include <map>
@@ -50,713 +55,534 @@ extern "C" double log2 ( double );
 #include <list>
 #include <algorithm>
 #include <ext/hash_map>
-#include <dlfcn.h>
-#include <AvailabilityMacros.h>
+#include <ext/hash_set>
+#include <cxxabi.h>
 
-#include "configure.h"
 #include "Options.h"
 
-#include "ObjectFile.h"
-
-#include "MachOReaderRelocatable.hpp"
-#include "ArchiveReader.hpp"
-#include "MachOReaderDylib.hpp"
-#include "MachOWriterExecutable.hpp"
-
-#if LTO_SUPPORT
-#include "LTOReader.hpp"
-#endif
+#include "MachOFileAbstraction.hpp"
+#include "Architectures.hpp"
+#include "ld.hpp"
+
+#include "InputFiles.h"
+#include "Resolver.h"
+#include "OutputFile.h"
+
+#include "passes/stubs/make_stubs.h"
+#include "passes/dtrace_dof.h"
+#include "passes/got.h"
+#include "passes/tlvp.h"
+#include "passes/huge.h"
+#include "passes/compact_unwind.h"
+#include "passes/order.h"
+#include "passes/branch_island.h"
+#include "passes/branch_shim.h"
+#include "passes/objc.h"
+#include "passes/dylibs.h"
+
+#include "parsers/archive_file.h"
+#include "parsers/macho_relocatable_file.h"
+#include "parsers/macho_dylib_file.h"
+#include "parsers/lto_file.h"
+#include "parsers/opaque_section_file.h"
+
+
+struct PerformanceStatistics {
+       uint64_t                                                startTool;
+       uint64_t                                                startInputFileProcessing;
+       uint64_t                                                startResolver;
+       uint64_t                                                startDylibs;
+       uint64_t                                                startPasses;
+       uint64_t                                                startOutput;
+       uint64_t                                                startDone;
+       vm_statistics_data_t                    vmStart;
+       vm_statistics_data_t                    vmEnd;
+};
 
-#include "OpaqueSection.hpp"
 
 
-class CStringComparor
-{
-public:
-       bool operator()(const char* left, const char* right) const { return (strcmp(left, right) < 0); }
-};
 
-class CStringEquals
-{
-public:
-       bool operator()(const char* left, const char* right) const { return (strcmp(left, right) == 0); }
-};
 
-class Section : public ObjectFile::Section
+class InternalState : public ld::Internal
 {
 public:
-       static Section* find(const char* sectionName, const char* segmentName, bool zeroFill, bool createIfNeeded=true);
-       static void             assignIndexes();
-       const char*             getName() { return fSectionName; }
+                                                                                       InternalState(const Options& opts) : _options(opts), _atomsOrderedInSections(false) { }
+       virtual ld::Internal::FinalSection*             addAtom(const ld::Atom& atom);
+       virtual ld::Internal::FinalSection*             getFinalSection(const ld::Section&);
+       
+       void                                                                    sortSections();
+       void                                                                    markAtomsOrdered() { _atomsOrderedInSections = true; }
+       virtual                                                                 ~InternalState() {}
 private:
-                                       Section(const char* sectionName, const char* segmentName, bool zeroFill);
 
-       struct Sorter {
-               static int      segmentOrdinal(const char* segName);
-               bool operator()(Section* left, Section* right);
+       class FinalSection : public ld::Internal::FinalSection 
+       {
+       public:
+                                                       FinalSection(const ld::Section& sect, uint32_t sectionsSeen, bool objFile);
+               static int                                      sectionComparer(const void* l, const void* r);
+               static const ld::Section&       outputSection(const ld::Section& sect, bool mergeZeroFill);
+               static const ld::Section&       objectOutputSection(const ld::Section& sect, bool makeTentativeDefsReal);
+       private:
+               friend class InternalState;
+               static uint32_t         sectionOrder(const ld::Section& sect, uint32_t sectionsSeen);
+               static uint32_t         segmentOrder(const ld::Section& sect, bool objFile);
+               uint32_t                        _segmentOrder;
+               uint32_t                        _sectionOrder;
+
+               static std::vector<const char*> _s_segmentsSeen;
+               static ld::Section              _s_DATA_data;
+               static ld::Section              _s_DATA_const;
+               static ld::Section              _s_TEXT_text;
+               static ld::Section              _s_TEXT_const;
+               static ld::Section              _s_DATA_nl_symbol_ptr;
+               static ld::Section              _s_DATA_common;
+               static ld::Section              _s_DATA_zerofill;
        };
-
-       typedef __gnu_cxx::hash_map<const char*, uint32_t, __gnu_cxx::hash<const char*>, CStringEquals> NameToOrdinal;
-       typedef __gnu_cxx::hash_map<const char*, class Section*, __gnu_cxx::hash<const char*>, CStringEquals> NameToSection;
-       //typedef std::map<const char*, class Section*, CStringComparor> NameToSection;
-
-       char                    fSectionName[18];
-       char                    fSegmentName[18];
-       bool                    fZeroFill;
-
-       static NameToSection                    fgMapping;
-       static std::vector<Section*>    fgSections;
-       static NameToOrdinal                    fgSegmentDiscoverOrder;
-};
-
-Section::NameToSection Section::fgMapping;
-std::vector<Section*>  Section::fgSections;
-Section::NameToOrdinal Section::fgSegmentDiscoverOrder;
-
-Section::Section(const char* sectionName, const char* segmentName, bool zeroFill)
- : fZeroFill(zeroFill)
-{
-       strlcpy(fSectionName, sectionName, sizeof(fSectionName));
-       strlcpy(fSegmentName, segmentName, sizeof(fSegmentName));
-       
-       this->fIndex = fgSections.size() + 20;  // room for 20 standard sections
-       // special placement of some sections
-       if ( strcmp(segmentName, "__TEXT") == 0 ) {
-               // sort unwind info to end of segment
-               if ( strcmp(sectionName, "__eh_frame") == 0 )
-                       this->fIndex = INT_MAX;
-               else if ( strcmp(sectionName, "__unwind_info") == 0 ) 
-                       this->fIndex = INT_MAX-1;
-               else if ( strcmp(sectionName, "__gcc_except_tab") == 0 ) 
-                       this->fIndex = INT_MAX-2;                       
-       }
-       else if ( strcmp(segmentName, "__DATA") == 0 ) {
-               // sort sections dyld will touch to start of segment
-               if ( strcmp(sectionName, "__dyld") == 0 )
-                       this->fIndex = 1;
-               else if ( strcmp(sectionName, "__program_vars") == 0 ) 
-                       this->fIndex = 1;
-               else if ( strcmp(sectionName, "__mod_init_func") == 0 ) 
-                       this->fIndex = 2;
-               else if ( strcmp(sectionName, "__nl_symbol_ptr") == 0 ) 
-                       this->fIndex = 3;
-               else if ( strcmp(sectionName, "__la_symbol_ptr") == 0 ) 
-                       this->fIndex = 4;
-               else if ( strcmp(sectionName, "__const") == 0 ) 
-                       this->fIndex = 5;
-               else if ( strcmp(sectionName, "__cfstring") == 0 ) 
-                       this->fIndex = 6;
-               else if ( strcmp(sectionName, "__gcc_except_tab") == 0 ) 
-                       this->fIndex = 7;
-               else if ( strcmp(sectionName, "__objc_data") == 0 ) 
-                       this->fIndex = 8;
-               else if ( strcmp(sectionName, "__objc_msgrefs") == 0 ) 
-                       this->fIndex = 9;
-               else if ( strcmp(sectionName, "__objc_protorefs") == 0 ) 
-                       this->fIndex = 10;
-               else if ( strcmp(sectionName, "__objc_selrefs") == 0 ) 
-                       this->fIndex = 11;
-               else if ( strcmp(sectionName, "__objc_classrefs") == 0 ) 
-                       this->fIndex = 12;
-               else if ( strcmp(sectionName, "__objc_superrefs") == 0 ) 
-                       this->fIndex = 13;
-               else if ( strcmp(sectionName, "__objc_const") == 0 ) 
-                       this->fIndex = 14;
-               else if ( strcmp(sectionName, "__objc_classlist") == 0 ) 
-                       this->fIndex = 15;
-               else if ( strcmp(sectionName, "__objc_nlclslist") == 0 ) 
-                       this->fIndex = 16;
-               else if ( strcmp(sectionName, "__objc_catlist") == 0 ) 
-                       this->fIndex = 17;
-               else if ( strcmp(sectionName, "__objc_protolist") == 0 ) 
-                       this->fIndex = 18;
-               else if ( strcmp(sectionName, "__objc_imageinfo") == 0 ) 
-                       this->fIndex = 19;
        
-       }
        
-       //fprintf(stderr, "new Section(%s, %s) => %p, %u\n", sectionName, segmentName, this, this->getIndex());
-}
-
-Section* Section::find(const char* sectionName, const char* segmentName, bool zeroFill, bool createIfNeeded)
-{
-       NameToSection::iterator pos = fgMapping.find(sectionName);
-       if ( pos != fgMapping.end() ) {
-               if ( strcmp(pos->second->fSegmentName, segmentName) == 0 )
-                       return pos->second;
-               // otherwise same section name is used in different segments, look slow way
-               for (std::vector<Section*>::iterator it=fgSections.begin(); it != fgSections.end(); it++) {
-                       if ( (strcmp((*it)->fSectionName, sectionName) == 0) && (strcmp((*it)->fSegmentName, segmentName) == 0) )
-                               return *it;
-               }
-       }
-
-       if ( !createIfNeeded ) 
-               return NULL;
+       struct SectionHash {
+               size_t operator()(const ld::Section*) const;
+       };
+       struct SectionEquals {
+               bool operator()(const ld::Section* left, const ld::Section* right) const;
+       };
+       typedef __gnu_cxx::hash_map<const ld::Section*, FinalSection*, SectionHash, SectionEquals> SectionInToOut;
        
-       // does not exist, so make a new one
-       Section* sect = new Section(sectionName, segmentName, zeroFill);
-       fgMapping[sectionName] = sect;
-       fgSections.push_back(sect);
 
-       if ( (strcmp(sectionName, "__text") == 0) && (strcmp(segmentName, "__TEXT") == 0) ) {
-               // special case __StaticInit to be right after __text
-               find("__StaticInit", "__TEXT", false);
-       }
+       SectionInToOut                  _sectionInToFinalMap;
+       const Options&                  _options;
+       bool                                    _atomsOrderedInSections;
+};
 
-       // remember segment discovery order
-       if ( fgSegmentDiscoverOrder.find(segmentName) == fgSegmentDiscoverOrder.end() ) 
-               fgSegmentDiscoverOrder[segmentName] = fgSegmentDiscoverOrder.size();
+ld::Section    InternalState::FinalSection::_s_DATA_data( "__DATA", "__data",  ld::Section::typeUnclassified);
+ld::Section    InternalState::FinalSection::_s_DATA_const("__DATA", "__const", ld::Section::typeUnclassified);
+ld::Section    InternalState::FinalSection::_s_TEXT_text( "__TEXT", "__text",  ld::Section::typeCode);
+ld::Section    InternalState::FinalSection::_s_TEXT_const("__TEXT", "__const", ld::Section::typeUnclassified);
+ld::Section    InternalState::FinalSection::_s_DATA_nl_symbol_ptr("__DATA", "__nl_symbol_ptr", ld::Section::typeNonLazyPointer);
+ld::Section    InternalState::FinalSection::_s_DATA_common("__DATA", "__common", ld::Section::typeZeroFill);
+ld::Section    InternalState::FinalSection::_s_DATA_zerofill("__DATA", "__zerofill", ld::Section::typeZeroFill);
+std::vector<const char*> InternalState::FinalSection::_s_segmentsSeen;
 
-       return sect;
-}
 
-int Section::Sorter::segmentOrdinal(const char* segName)
+size_t InternalState::SectionHash::operator()(const ld::Section* sect) const
 {
-       if ( strcmp(segName, "__HEADER") == 0 )
-               return 1;
-       if ( strcmp(segName, "__PAGEZERO") == 0 )
-               return 1;
-       if ( strcmp(segName, "__TEXT") == 0 )
-               return 2;
-       if ( strcmp(segName, "__DATA") == 0 )
-               return 3;
-       if ( strcmp(segName, "__OBJC") == 0 )
-               return 4;
-       if ( strcmp(segName, "__OBJC2") == 0 )
-               return 5;
-       if ( strcmp(segName, "__LINKEDIT") == 0 )
-               return INT_MAX; // linkedit segment should always sort last
-       else
-               return fgSegmentDiscoverOrder[segName]+6;
+       size_t hash = 0;        
+       __gnu_cxx::hash<const char*> temp;
+       hash += temp.operator()(sect->segmentName());
+       hash += temp.operator()(sect->sectionName());
+       return hash;
 }
 
-
-bool Section::Sorter::operator()(Section* left, Section* right)
+bool InternalState::SectionEquals::operator()(const ld::Section* left, const ld::Section* right) const
 {
-       // Segment is primary sort key
-       int leftSegOrdinal = segmentOrdinal(left->fSegmentName);
-       int rightSegOrdinal = segmentOrdinal(right->fSegmentName);
-       if ( leftSegOrdinal < rightSegOrdinal )
-               return true;
-       if ( leftSegOrdinal > rightSegOrdinal )
-               return false;
-
-       // zerofill section sort to the end
-       if ( !left->fZeroFill && right->fZeroFill )
-               return true;
-       if ( left->fZeroFill && !right->fZeroFill )
-               return false;
-
-       // section discovery order is last sort key
-       return left->fIndex < right->fIndex;
+       return (*left == *right);
 }
 
-void Section::assignIndexes()
-{      
-       //printf("unsorted sections:\n");
-       //for (std::vector<Section*>::iterator it=fgSections.begin(); it != fgSections.end(); it++) {
-       //      printf("section: name=%s, segment: name=%s, discovery order=%d\n", (*it)->fSectionName, (*it)->fSegmentName, (*it)->fIndex);
-       //}
-
-       // sort it
-       std::sort(fgSections.begin(), fgSections.end(), Section::Sorter());
 
-       // assign correct section ordering to each Section object
-       unsigned int newOrder = 1;
-       for (std::vector<Section*>::iterator it=fgSections.begin(); it != fgSections.end(); it++)
-               (*it)->fIndex = newOrder++;
-
-       //printf("sorted sections:\n");
-       //for (std::vector<Section*>::iterator it=fgSections.begin(); it != fgSections.end(); it++) {
-       //      printf("section: index=%d, obj=%p, name=%s\n", (*it)->fIndex, (*it), (*it)->fSectionName);
-       //}
+InternalState::FinalSection::FinalSection(const ld::Section& sect, uint32_t sectionsSeen, bool objFile)
+       : ld::Internal::FinalSection(sect), 
+         _segmentOrder(segmentOrder(sect, objFile)),
+         _sectionOrder(sectionOrder(sect, sectionsSeen))
+{
+       //fprintf(stderr, "FinalSection(%s, %s) _segmentOrder=%d, _sectionOrder=%d\n", 
+       //              this->segmentName(), this->sectionName(), _segmentOrder, _sectionOrder);
 }
 
-class Linker : public ObjectFile::Reader::DylibHander {
-public:
-                                               Linker(int argc, const char* argv[]);
-
-       const char*                     getArchPrefix();
-       const char*                     architectureName();
-       bool                            showArchitectureInErrors();
-       bool                            isInferredArchitecture();
-       void                            createReaders();
-       void                            createWriter();
-       void                            addInputFile(ObjectFile::Reader* reader, const Options::FileInfo& );
-       void                            setOutputFile(ExecutableFile::Writer* writer);
-       void                            link();
-       void                            optimize();
-       
-       // implemenation from ObjectFile::Reader::DylibHander
-       virtual ObjectFile::Reader* findDylib(const char* installPath, const char* fromPath);
-
-private:
-       struct WhyLiveBackChain
-       {
-               WhyLiveBackChain*       previous;
-               ObjectFile::Atom*       referer;
-       };
-
-       ObjectFile::Reader*     createReader(const Options::FileInfo&);
-       void                            addAtom(ObjectFile::Atom& atom);
-       void                            addAtoms(std::vector<class ObjectFile::Atom*>& atoms);
-       void                            buildAtomList();
-       void                            adjustScope();
-       void                            processDylibs();
-       void                            markDead(ObjectFile::Atom* atom);
-       void                            updateConstraints(ObjectFile::Reader* reader);
-       void                            loadAndResolve();
-       void                            processDTrace();
-       void                            checkObjC();
-       void                            loadUndefines();
-       void                            checkUndefines();
-       void                            resolveReferences();
-       void                            deadStripResolve();
-       void                            addLiveRoot(const char* name);
-       void                            moveToFrontOfSection(ObjectFile::Atom* atom);
-       ObjectFile::Atom*       findAtom(const Options::OrderedSymbol& pair);
-       void                            logArchive(ObjectFile::Reader* reader);
-       void                            sortSections();
-       void                            sortAtoms();
-       void                            tweakLayout();
-       void                            writeDotOutput();
-       static bool                     minimizeStab(ObjectFile::Reader::Stab& stab);
-       static const char*      truncateStabString(const char* str);
-       void                            collectDebugInfo();
-       void                            writeOutput();
-       ObjectFile::Atom*       entryPoint(bool orInit);
-       ObjectFile::Atom*       dyldClassicHelper();
-       ObjectFile::Atom*       dyldCompressedHelper();
-       ObjectFile::Atom*       dyldLazyLibraryHelper();
-       const char*                     assureFullPath(const char* path);
-       void                            markLive(ObjectFile::Atom& atom, Linker::WhyLiveBackChain* previous);
-       void                            collectStabs(ObjectFile::Reader* reader, std::map<const class ObjectFile::Atom*, uint32_t>& atomOrdinals);
-       void                            synthesizeDebugNotes(std::vector<class ObjectFile::Atom*>& allAtomsByReader);
-       void                            printStatistics();
-       void                            printTime(const char* msg, uint64_t partTime, uint64_t totalTime);
-       char*                           commatize(uint64_t in, char* out);
-       void                            getVMInfo(vm_statistics_data_t& info);
-       cpu_type_t                      inferArchitecture();
-       void                            checkDylibClientRestrictions(ObjectFile::Reader* reader);
-       void                            logDylib(ObjectFile::Reader* reader, bool indirect);
-       
-       void                                                                    resolve(ObjectFile::Reference* reference);
-       void                                                                    resolveFrom(ObjectFile::Reference* reference);
-       std::vector<class ObjectFile::Atom*>*   addJustInTimeAtoms(const char* name, bool searchDylibs, bool searchArchives, bool okToMakeProxy);
-       void                                                                    addJustInTimeAtomsAndMarkLive(const char* name);
-
-       ObjectFile::Reader*     addDylib(ObjectFile::Reader* reader, const Options::FileInfo& info, uint64_t mappedLen);
-       ObjectFile::Reader*     addObject(ObjectFile::Reader* reader, const Options::FileInfo& info, uint64_t mappedLen);
-       ObjectFile::Reader*     addArchive(ObjectFile::Reader* reader, const Options::FileInfo& info, uint64_t mappedLen);
-
-       void                            logTraceInfo(const char* format, ...);
-
-
-       class SymbolTable
-       {
-       public:
-               typedef __gnu_cxx::hash_map<const char*, ObjectFile::Atom*, __gnu_cxx::hash<const char*>, CStringEquals> Mapper;
-
-                                                       SymbolTable(Linker&);
-               void                            require(const char* name);
-               bool                            add(ObjectFile::Atom& atom);
-               ObjectFile::Atom*       find(const char* name);
-               unsigned int            getRequireCount() { return fRequireCount; }
-               void                            getUndefinesNames(std::vector<const char*>& undefines);
-               void                            getTentativesNames(std::vector<const char*>& tents);
-               bool                            hasExternalTentativeDefinitions() { return fHasExternalTentativeDefinitions; }
-               bool                            hasExternalWeakDefinitions() { return fHasExternalWeakDefinitions; }
-               void                            setHasExternalWeakDefinitions(bool value) { fHasExternalWeakDefinitions = value; }
-               Mapper::iterator        begin() { return fTable.begin(); }
-               Mapper::iterator        end()   { return fTable.end(); }
-
-       private:
-               Linker&                         fOwner;
-               Mapper                          fTable;
-               unsigned int            fRequireCount;
-               bool                            fHasExternalTentativeDefinitions;
-               bool                            fHasExternalWeakDefinitions;
-       };
-
-       class AtomSorter
-       {
-       public:
-               AtomSorter(std::map<const ObjectFile::Atom*, uint32_t>* map, std::set<const ObjectFile::Atom*>& inits, 
-                                                       std::set<const ObjectFile::Atom*>& terms) : 
-                               fOverriddenOrdinalMap(map), fInitializerSet(inits), fTerminatorSet(terms) {}
-               bool operator()(const ObjectFile::Atom* left, const ObjectFile::Atom* right);
-       private:
-               std::map<const ObjectFile::Atom*, uint32_t>*    fOverriddenOrdinalMap;
-               std::set<const ObjectFile::Atom*>&                              fInitializerSet;
-               std::set<const ObjectFile::Atom*>&                              fTerminatorSet;
-       };
-
-       typedef std::map<const char*, uint32_t, CStringComparor> SectionOrder;
-
-       struct DTraceProbeInfo {
-               DTraceProbeInfo(const ObjectFile::Atom* a, uint32_t o, const char* n) : atom(a), offset(o), probeName(n) {}
-               const ObjectFile::Atom*                 atom;
-               uint32_t                                                offset;
-               const char*                                             probeName;
-       };
-       typedef __gnu_cxx::hash_map<const char*, std::vector<DTraceProbeInfo>, __gnu_cxx::hash<const char*>, CStringEquals>     ProviderToProbes;
-       typedef __gnu_cxx::hash_set<const char*, __gnu_cxx::hash<const char*>, CStringEquals>  CStringSet;
-       typedef __gnu_cxx::hash_map<const char*, ObjectFile::Reader*, __gnu_cxx::hash<const char*>, CStringEquals>      InstallNameToReader;
-
-       struct IndirectLibrary {
-               const char*                                                     path;
-               uint64_t                                                        fileLen;
-               ObjectFile::Reader*                                     reader;
-               std::set<ObjectFile::Reader*>           parents;
-               ObjectFile::Reader*                                     reExportedViaDirectLibrary;
-       };
-
-       ObjectFile::Reader* findDirectLibraryWhichReExports(struct IndirectLibrary& indirectLib);
-
-       Options                                                                                         fOptions;
-       SymbolTable                                                                                     fGlobalSymbolTable;
-       uint32_t                                                                                        fNextInputOrdinal;
-       std::vector<class ObjectFile::Reader*>                          fInputFiles;
-       ExecutableFile::Writer*                                                         fOutputFile;
-       InstallNameToReader                                                                     fDylibMap;
-       std::map<ObjectFile::Reader*,LibraryOptions>            fDylibOptionsMap;
-       std::set<ObjectFile::Reader*>                                           fDylibsProcessed;
-       ObjectFile::Reader*                                                                     fBundleLoaderReader;
-       std::vector<class ObjectFile::Reader*>                          fReadersThatHaveSuppliedAtoms;
-       std::vector<class ObjectFile::Atom*>                            fAllAtoms;
-       std::set<class ObjectFile::Reader*>                                     fArchiveReaders;
-       std::set<class ObjectFile::Reader*>                                     fArchiveReadersLogged;
-       std::set<class ObjectFile::Atom*>                                       fDeadAtoms;
-       std::set<ObjectFile::Atom*>                                                     fLiveAtoms;
-       std::set<ObjectFile::Atom*>                                                     fLiveRootAtoms;
-       std::set<const ObjectFile::Atom*>                                       fInitializerAtoms;
-       std::set<const ObjectFile::Atom*>                                       fTerminatorAtoms;
-       std::set<const ObjectFile::Atom*>                                       fRegularDefAtomsThatOverrideADylibsWeakDef;
-       std::vector<class ObjectFile::Reader::Stab>                     fStabs;
-       std::vector<class ObjectFile::Atom*>                            fAtomsWithUnresolvedReferences;
-       std::set<class ObjectFile::Atom*>                                       fAtomsOverriddenByLateLoads;
-       bool                                                                                            fInitialLoadsDone;
-       bool                                                                                            fCreateUUID;
-       bool                                                                                            fCanScatter;
-       SectionOrder                                                                            fSectionOrder;
-       cpu_type_t                                                                                      fArchitecture;
-       const char*                                                                                     fArchitectureName;
-       bool                                                                                            fArchitectureInferred;
-       bool                                                                                            fDirectLibrariesComplete;
-       bool                                                                                            fBiggerThanTwoGigOutput;
-       uint64_t                                                                                        fOutputFileSize;
-       uint64_t                                                                                        fTotalZeroFillSize;
-       uint64_t                                                                                        fTotalSize;
-       uint64_t                                                                                        fStartTime;
-       uint64_t                                                                                        fStartCreateReadersTime;
-       uint64_t                                                                                        fStartCreateWriterTime;
-       uint64_t                                                                                        fStartBuildAtomsTime;
-       uint64_t                                                                                        fStartLoadAndResolveTime;
-       uint64_t                                                                                        fStartSortTime;
-       uint64_t                                                                                        fStartDebugTime;
-       uint64_t                                                                                        fStartWriteTime;
-       uint64_t                                                                                        fEndTime;
-       uint64_t                                                                                        fTotalObjectSize;
-       uint64_t                                                                                        fTotalArchiveSize;
-       uint32_t                                                                                        fTotalObjectLoaded;
-       uint32_t                                                                                        fTotalArchivesLoaded;
-       uint32_t                                                                                        fTotalDylibsLoaded;
-       vm_statistics_data_t                                                            fStartVMInfo;
-       ObjectFile::Reader::ObjcConstraint                                      fCurrentObjCConstraint;
-       ObjectFile::Reader::CpuConstraint                                       fCurrentCpuConstraint;
-       bool                                                                                            fObjcReplacmentClasses;
-       bool                                                                                            fAllDirectDylibsLoaded;
-};
-
-
-Linker::Linker(int argc, const char* argv[])
-       : fOptions(argc, argv), fGlobalSymbolTable(*this), fNextInputOrdinal(1), fOutputFile(NULL), fBundleLoaderReader(NULL), 
-         fInitialLoadsDone(false), fCreateUUID(fOptions.outputKind() != Options::kObjectFile), fCanScatter(true),
-         fArchitecture(0), fArchitectureInferred(false), fDirectLibrariesComplete(false), fBiggerThanTwoGigOutput(false),
-         fOutputFileSize(0), fTotalZeroFillSize(0), fTotalSize(0), fTotalObjectSize(0),
-         fTotalArchiveSize(0),  fTotalObjectLoaded(0), fTotalArchivesLoaded(0), fTotalDylibsLoaded(0),
-         fCurrentObjCConstraint(ObjectFile::Reader::kObjcNone), fCurrentCpuConstraint(ObjectFile::Reader::kCpuAny),
-         fObjcReplacmentClasses(false), fAllDirectDylibsLoaded(false)
+const ld::Section& InternalState::FinalSection::outputSection(const ld::Section& sect, bool mergeZeroFill)
 {
-       fStartTime = mach_absolute_time();
-       if ( fOptions.printStatistics() )
-               getVMInfo(fStartVMInfo);
-
-       fArchitecture = fOptions.architecture();
-       if ( fArchitecture == 0 ) {
-               // -arch not specified, scan .o files to figure out what it should be
-               fArchitecture = inferArchitecture();
-               fArchitectureInferred = true;
-       }
-       switch (fArchitecture) {
-               case CPU_TYPE_POWERPC:
-                       fArchitectureName = "ppc";
+       // merge sections in final linked image
+       switch ( sect.type() ) {
+               case ld::Section::typeLiteral4:
+               case ld::Section::typeLiteral8:
+               case ld::Section::typeLiteral16:
+                       return _s_TEXT_const;
+               case ld::Section::typeUnclassified:
+                       if ( strcmp(sect.segmentName(), "__DATA") == 0 ) {
+                               if ( strcmp(sect.sectionName(), "__datacoal_nt") == 0 )
+                                       return _s_DATA_data;
+                               if ( strcmp(sect.sectionName(), "__const_coal") == 0 )
+                                       return _s_DATA_const;
+                       }
+                       else if ( strcmp(sect.segmentName(), "__TEXT") == 0 ) {
+                               if ( strcmp(sect.sectionName(), "__const_coal") == 0 )
+                                       return _s_TEXT_const;
+                       }
                        break;
-               case CPU_TYPE_POWERPC64:
-                       fArchitectureName = "ppc64";
+               case ld::Section::typeZeroFill:
+                       if ( mergeZeroFill )
+                               return _s_DATA_zerofill;
                        break;
-               case CPU_TYPE_I386:
-                       fArchitectureName = "i386";
+               case ld::Section::typeCode:
+                       if ( strcmp(sect.segmentName(), "__TEXT") == 0 ) {
+                               if ( strcmp(sect.sectionName(), "__textcoal_nt") == 0 )
+                                       return _s_TEXT_text;
+                               else if ( strcmp(sect.sectionName(), "__StaticInit") == 0 )
+                                       return _s_TEXT_text;
+                       }
                        break;
-               case CPU_TYPE_X86_64:
-                       fArchitectureName = "x86_64";
+               case ld::Section::typeNonLazyPointer:
+                       if ( strcmp(sect.segmentName(), "__DATA") == 0 ) {
+                               if ( strcmp(sect.sectionName(), "__nl_symbol_ptr") == 0 )
+                                       return _s_DATA_nl_symbol_ptr;
+                       }
+                       else if ( strcmp(sect.segmentName(), "__IMPORT") == 0 ) {
+                               if ( strcmp(sect.sectionName(), "__pointers") == 0 )
+                                       return _s_DATA_nl_symbol_ptr; 
+                       }
                        break;
-               case CPU_TYPE_ARM:
-                       fArchitectureName = "arm";
+               case ld::Section::typeTentativeDefs:
+                       if ( mergeZeroFill )
+                               return _s_DATA_zerofill;
+                       else
+                               return _s_DATA_common;
                        break;
+                       // FIX ME: more 
                default:
-                       fArchitectureName = "unknown architecture";
                        break;
        }
+       return sect;
 }
 
-const char*    Linker::architectureName()
-{
-       return fArchitectureName;
-}
-
-bool Linker::showArchitectureInErrors()
+const ld::Section& InternalState::FinalSection::objectOutputSection(const ld::Section& sect, bool makeTentativeDefsReal)
 {
-       return fOptions.printArchPrefix();
+       // in -r mode the only section that ever changes is __tenative -> __common with -d option
+       if ( (sect.type() == ld::Section::typeTentativeDefs) && makeTentativeDefsReal)
+               return _s_DATA_common;
+       return sect;
 }
 
-bool Linker::isInferredArchitecture()
+uint32_t InternalState::FinalSection::segmentOrder(const ld::Section& sect, bool objFile)
 {
-       return fArchitectureInferred;
+       if ( strcmp(sect.segmentName(), "__PAGEZERO") == 0 ) 
+               return 0;
+       if ( strcmp(sect.segmentName(), "__HEADER") == 0 ) // only used with -preload
+               return 0;
+       if ( strcmp(sect.segmentName(), "__TEXT") == 0 ) 
+               return 1;
+       // in -r mode, want __DATA  last so zerofill sections are at end
+       if ( strcmp(sect.segmentName(), "__DATA") == 0 ) 
+               return (objFile ? 5 : 2);
+       if ( strcmp(sect.segmentName(), "__OBJC") == 0 ) 
+               return 3;
+       if ( strcmp(sect.segmentName(), "__IMPORT") == 0 ) 
+               return 4;
+       
+       // layout non-standard segments in order seen (+10 to shift beyond standard segments)
+       for (uint32_t i=0; i < _s_segmentsSeen.size(); ++i) {
+               if ( strcmp(_s_segmentsSeen[i], sect.segmentName()) == 0 )
+                       return i+10;
+       }
+       _s_segmentsSeen.push_back(sect.segmentName());
+       return _s_segmentsSeen.size()-1+10;
 }
 
-cpu_type_t Linker::inferArchitecture()
+uint32_t InternalState::FinalSection::sectionOrder(const ld::Section& sect, uint32_t sectionsSeen)
 {
-       // scan all input files, looking for a thin .o file.
-       // the first one found is presumably the architecture to link
-       uint8_t buffer[sizeof(mach_header_64)];
-       std::vector<Options::FileInfo>& files = fOptions.getInputFiles();
-       for (std::vector<Options::FileInfo>::iterator it = files.begin(); it != files.end(); ++it) {
-               int fd = ::open(it->path, O_RDONLY, 0);
-               if ( fd != -1 ) {
-                       ssize_t amount = read(fd, buffer, sizeof(buffer));
-                       ::close(fd);
-                       if ( amount >= (ssize_t)sizeof(buffer) ) {
-                               if ( mach_o::relocatable::Reader<ppc>::validFile(buffer) ) {
-                                       //warning("-arch not used, infering -arch ppc based on %s", it->path);
-                                       return CPU_TYPE_POWERPC;
-                               }
-                               else if ( mach_o::relocatable::Reader<ppc64>::validFile(buffer) ) {
-                                       //warning("-arch not used, infering -arch ppc64 based on %s", it->path);
-                                       return CPU_TYPE_POWERPC64;
-                               }
-                               else if ( mach_o::relocatable::Reader<x86>::validFile(buffer) ) {
-                                       //warning("-arch not used, infering -arch i386 based on %s", it->path);
-                                       return CPU_TYPE_I386;
-                               }
-                               else if ( mach_o::relocatable::Reader<x86_64>::validFile(buffer) ) {
-                                       //warning("-arch not used, infering -arch x86_64 based on %s", it->path);
-                                       return CPU_TYPE_X86_64;
-                               }
-                               else if ( mach_o::relocatable::Reader<arm>::validFile(buffer) ) {
-                                       //warning("-arch not used, infering -arch arm based on %s", it->path);
-                                       return CPU_TYPE_ARM;
-                               }
+       if ( sect.type() == ld::Section::typeFirstSection )
+               return 0;
+       if ( sect.type() == ld::Section::typeMachHeader )
+               return 1;
+       if ( sect.type() == ld::Section::typeLastSection )
+               return INT_MAX;
+       if ( strcmp(sect.segmentName(), "__TEXT") == 0 ) {
+               switch ( sect.type() ) {
+                       case ld::Section::typeCode:
+                               // <rdar://problem/8346444> make __text always be first "code" section
+                               if ( strcmp(sect.sectionName(), "__text") == 0 )
+                                       return 10;
+                               else
+                                       return 11;
+                       case ld::Section::typeStub:
+                               return 12;
+                       case ld::Section::typeStubHelper:
+                               return 13;
+                       case ld::Section::typeLSDA:
+                               return INT_MAX-3;
+                       case ld::Section::typeUnwindInfo:
+                               return INT_MAX-2;
+                       case ld::Section::typeCFI:
+                               return INT_MAX-1;
+                       case ld::Section::typeStubClose:
+                               return INT_MAX;
+                       default:
+                               return sectionsSeen+20;
+               }
+       }
+       else if ( strcmp(sect.segmentName(), "__DATA") == 0 ) {
+               switch ( sect.type() ) {
+                       case ld::Section::typeLazyPointerClose:
+                               return 8;
+                       case ld::Section::typeDyldInfo:
+                               return 9;
+                       case ld::Section::typeNonLazyPointer:
+                               return 10;
+                       case ld::Section::typeLazyPointer:
+                               return 11;
+                       case ld::Section::typeInitializerPointers:
+                               return 12;
+                       case ld::Section::typeTerminatorPointers:
+                               return 13;
+                       case ld::Section::typeTLVInitialValues:
+                               return INT_MAX-4; // need TLV zero-fill to follow TLV init values
+                       case ld::Section::typeTLVZeroFill:
+                               return INT_MAX-3;
+                       case ld::Section::typeZeroFill:
+                               // make sure __huge is always last zerofill section
+                               if ( strcmp(sect.sectionName(), "__huge") == 0 )
+                                       return INT_MAX-1;
+                               else
+                                       return INT_MAX-2;
+                       default:
+                               // <rdar://problem/7435296> Reorder sections to reduce page faults in object files
+                               if ( strcmp(sect.sectionName(), "__objc_classlist") == 0 ) 
+                                       return 20;
+                               else if ( strcmp(sect.sectionName(), "__objc_nlclslist") == 0 ) 
+                                       return 21;
+                               else if ( strcmp(sect.sectionName(), "__objc_catlist") == 0 ) 
+                                       return 22;
+                               else if ( strcmp(sect.sectionName(), "__objc_protolist") == 0 ) 
+                                       return 23;
+                               else if ( strcmp(sect.sectionName(), "__objc_imageinfo") == 0 ) 
+                                       return 24;
+                               else if ( strcmp(sect.sectionName(), "__objc_const") == 0 ) 
+                                       return 25;
+                               else if ( strcmp(sect.sectionName(), "__objc_selrefs") == 0 ) 
+                                       return 26;
+                               else if ( strcmp(sect.sectionName(), "__objc_msgrefs") == 0 ) 
+                                       return 27;
+                               else if ( strcmp(sect.sectionName(), "__objc_protorefs") == 0 ) 
+                                       return 28;
+                               else if ( strcmp(sect.sectionName(), "__objc_classrefs") == 0 ) 
+                                       return 29;
+                               else if ( strcmp(sect.sectionName(), "__objc_superrefs") == 0 ) 
+                                       return 30;
+                               else if ( strcmp(sect.sectionName(), "__objc_data") == 0 ) 
+                                       return 31;
+                               else
+                                       return sectionsSeen+40;
+               }
+       }
+       // make sure zerofill in any other section is at end of segment
+       if ( sect.type() == ld::Section::typeZeroFill )
+               return INT_MAX-1;
+       return sectionsSeen+20;
+}
+
+#ifndef NDEBUG
+static void validateFixups(const ld::Atom& atom)
+{
+       //fprintf(stderr, "validateFixups %s\n", atom.name());
+       bool lastWasClusterEnd = true;
+       ld::Fixup::Cluster lastClusterSize = ld::Fixup::k1of1;
+       uint32_t curClusterOffsetInAtom = 0;
+       for (ld::Fixup::iterator fit=atom.fixupsBegin(); fit != atom.fixupsEnd(); ++fit) {
+               //fprintf(stderr, "  fixup offset=%d, cluster=%d\n", fit->offsetInAtom, fit->clusterSize);
+               assert((fit->offsetInAtom < atom.size()) || (fit->offsetInAtom == 0));
+               if ( fit->firstInCluster() ) {
+                       assert(lastWasClusterEnd);
+                       curClusterOffsetInAtom = fit->offsetInAtom;
+                       lastWasClusterEnd = (fit->clusterSize == ld::Fixup::k1of1);
+               }
+               else {
+                       assert(!lastWasClusterEnd);
+                       assert(fit->offsetInAtom == curClusterOffsetInAtom);
+                       switch ((ld::Fixup::Cluster)fit->clusterSize) {
+                               case ld::Fixup::k1of1:
+                               case ld::Fixup::k1of2:
+                               case ld::Fixup::k1of3:
+                               case ld::Fixup::k1of4:
+                               case ld::Fixup::k1of5:
+                                       lastWasClusterEnd = false;
+                                       break;
+                               case ld::Fixup::k2of2:
+                                       assert(lastClusterSize = ld::Fixup::k1of2);
+                                       lastWasClusterEnd = true;
+                                       break;
+                               case ld::Fixup::k2of3:
+                                       assert(lastClusterSize = ld::Fixup::k1of3);
+                                       lastWasClusterEnd = false;
+                                       break;
+                               case ld::Fixup::k2of4:
+                                       assert(lastClusterSize = ld::Fixup::k1of4);
+                                       lastWasClusterEnd = false;
+                                       break;
+                               case ld::Fixup::k2of5:
+                                       assert(lastClusterSize = ld::Fixup::k1of5);
+                                       lastWasClusterEnd = false;
+                                       break;
+                               case ld::Fixup::k3of3:
+                                       assert(lastClusterSize = ld::Fixup::k2of3);
+                                       lastWasClusterEnd = true;
+                                       break;
+                               case ld::Fixup::k3of4:
+                                       assert(lastClusterSize = ld::Fixup::k2of4);
+                                       lastWasClusterEnd = false;
+                                       break;
+                               case ld::Fixup::k3of5:
+                                       assert(lastClusterSize = ld::Fixup::k2of5);
+                                       lastWasClusterEnd = false;
+                                       break;
+                               case ld::Fixup::k4of4:
+                                       assert(lastClusterSize = ld::Fixup::k3of4);
+                                       lastWasClusterEnd = true;
+                                       break;
+                               case ld::Fixup::k4of5:
+                                       assert(lastClusterSize = ld::Fixup::k3of5);
+                                       lastWasClusterEnd = false;
+                                       break;
+                               case ld::Fixup::k5of5:
+                                       assert(lastClusterSize = ld::Fixup::k4of5);
+                                       lastWasClusterEnd = true;
+                                       break;
                        }
                }
+               lastClusterSize = fit->clusterSize;
+               if ( fit->binding == ld::Fixup::bindingDirectlyBound ) {
+                       assert(fit->u.target != NULL);
+               }
        }
-
-       // no thin .o files found, so default to same architecture this was built as
-       warning("-arch not specified");
-#if __ppc__
-       return CPU_TYPE_POWERPC;
-#elif __i386__
-       return CPU_TYPE_I386;
-#elif __ppc64__
-       return CPU_TYPE_POWERPC64;
-#elif __x86_64__
-       return CPU_TYPE_X86_64;
-#elif __arm__
-       return CPU_TYPE_ARM;
-#else
-       #error unknown default architecture
-#endif
-}
-
-
-void Linker::addInputFile(ObjectFile::Reader* reader, const Options::FileInfo& info)
-{
-       fInputFiles.push_back(reader);
-       fDylibOptionsMap[reader] = info.options;
-}
-
-void Linker::setOutputFile(ExecutableFile::Writer* writer)
-{
-       fOutputFile = writer;
-}
-
-class InSet
-{
-public:
-       InSet(std::set<ObjectFile::Atom*>& deadAtoms) : fDeadAtoms(deadAtoms) {}
-
-       bool operator()(ObjectFile::Atom*& atom) const {
-               return ( fDeadAtoms.count(atom) != 0 );
-       }
-
-private:
-       std::set<ObjectFile::Atom*>& fDeadAtoms;
-};
-
-void Linker::loadAndResolve()
-{
-       fStartLoadAndResolveTime = mach_absolute_time();
-       if ( fOptions.deadStrip() == Options::kDeadStripOff ) {
-               // without dead-code-stripping:
-               // find atoms to resolve all undefines
-               this->loadUndefines();
-               // verify nothing is missing
-               this->checkUndefines();
-               // once all undefines fulfill, then bind all references
-               this->resolveReferences();
-               // remove atoms weak atoms that have been overridden
-               fAllAtoms.erase(std::remove_if(fAllAtoms.begin(), fAllAtoms.end(), InSet(fDeadAtoms)), fAllAtoms.end());
-       }
-       else {
-               // with dead code stripping:
-               // start binding references from roots,
-               this->deadStripResolve();
-               // verify nothing is missing
-               this->checkUndefines();
+       switch (lastClusterSize) {
+               case ld::Fixup::k1of1:
+               case ld::Fixup::k2of2:
+               case ld::Fixup::k3of3:
+               case ld::Fixup::k4of4:
+               case ld::Fixup::k5of5:
+                       break;
+               default:
+                       assert(0 && "last fixup was not end of cluster");
+                       break;
        }
 }
+#endif
 
-void Linker::optimize()
+ld::Internal::FinalSection* InternalState::addAtom(const ld::Atom& atom)
 {
-       // give each reader a chance to do any optimizations
-       bool didSomething = false;
-       std::vector<class ObjectFile::Atom*> newAtoms;
-       std::vector<const char *> additionalUndefines;
-       std::vector<class ObjectFile::Atom*> newlyDeadAtoms;
-       for (std::vector<class ObjectFile::Reader*>::iterator it=fInputFiles.begin(); it != fInputFiles.end(); it++) {
-               didSomething |= (*it)->optimize(fAllAtoms, newAtoms, additionalUndefines, fDeadAtoms, newlyDeadAtoms, fNextInputOrdinal, 
-                       fOutputFile, entryPoint(true), fOptions.llvmOptions(),
-                        fOptions.allGlobalsAreDeadStripRoots(), (int)fOptions.outputKind(), fOptions.verbose(),
-                       fOptions.saveTempFiles(), fOptions.getOutputFilePath(), fOptions.positionIndependentExecutable(),
-                       fOptions.allowTextRelocs());
-       }
-       
-       // only do next steps if some optimization was actually done
-       if  ( didSomething ) {
-               // add all newly created atoms to fAllAtoms and update symbol table
-               this->addAtoms(newAtoms);
-
-               // add dead atoms to dead list and remove from fAllAtoms
-               for(std::vector<class ObjectFile::Atom*>::iterator itr = newlyDeadAtoms.begin(); itr != newlyDeadAtoms.end(); ++itr) 
-                       markDead(*itr);
-               fAllAtoms.erase(std::remove_if(fAllAtoms.begin(), fAllAtoms.end(), InSet(fDeadAtoms)), fAllAtoms.end());
-
-               // Make sure all atoms have a section.  Atoms that were not originally in a mach-o file could
-               // not have their section set until now.
-               for(std::vector<class ObjectFile::Atom*>::iterator itr = fAllAtoms.begin(); itr != fAllAtoms.end(); ++itr) {
-                       ObjectFile::Atom *atom = *itr;
-                       if ( atom->getSection() == NULL )
-                               atom->setSection(Section::find(atom->getSectionName(), atom->getSegment().getName(), atom->isZeroFill()));
-               }
-
-               // resolve new undefines
-               for(std::vector<const char*>::iterator riter = additionalUndefines.begin(); riter != additionalUndefines.end(); ++riter) {
-                       const char *targetName = *riter;
-                       //fprintf(stderr, "LTO additional undefine: %s\n", targetName);
-                       ObjectFile::Atom* target = fGlobalSymbolTable.find(targetName);
-                       if ( target == NULL) {
-                               // mark that this symbol is needed
-                               fGlobalSymbolTable.require(targetName);
-                               // try to find it in some library
-                               this->addJustInTimeAtoms(targetName, true, true, true);
-                       }
-               }
-               
-               if ( fOptions.deadStrip() != Options::kDeadStripOff ) {
-                       // LTO may optimize away some atoms, so dead stripping must be redone
-                       fLiveAtoms.clear();
-                       this->deadStripResolve();
+       ld::Internal::FinalSection* fs = this->getFinalSection(atom.section());
+       //fprintf(stderr, "InternalState::doAtom(%p), name=%s, sect=%s, finalsect=%p\n", &atom, atom.name(), atom.section().sectionName(), fs);
+#ifndef NDEBUG
+       validateFixups(atom);
+#endif
+       if ( _atomsOrderedInSections ) {
+               // make sure this atom is placed before any trailing section$end$ atom
+               if ( (fs->atoms.size() > 1) && (fs->atoms.back()->contentType() == ld::Atom::typeSectionEnd) ) {
+                       // last atom in section$end$ atom, insert before it
+                       const ld::Atom* endAtom = fs->atoms.back();
+                       fs->atoms.pop_back();
+                       fs->atoms.push_back(&atom);
+                       fs->atoms.push_back(endAtom);
                }
                else {
-                       // LTO may require new library symbols to be loaded, so redo
-                       this->checkUndefines();
-                       this->resolveReferences();
+                       // not end atom, just append new atom
+                       fs->atoms.push_back(&atom);
                }
        }
+       else {
+               // normal case
+               fs->atoms.push_back(&atom);
+       }
+       return fs;
 }
 
+ld::Internal::FinalSection* InternalState::getFinalSection(const ld::Section& inputSection)
+{      
+       const ld::Section* baseForFinalSection = &inputSection;
+       
+       // see if input section already has a FinalSection
+       SectionInToOut::iterator pos = _sectionInToFinalMap.find(&inputSection);
+       if ( pos != _sectionInToFinalMap.end() ) {
+               return pos->second;
+       }
 
-void Linker::adjustScope()
-{
-       // if -exported_symbols_list is used, demoted to hidden, symbols that are not in it 
-       if ( fOptions.hasExportRestrictList() ) {
-               // The use of an -export file means the previous computation of fHasExternalWeakDefinitions could change
-               fGlobalSymbolTable.setHasExternalWeakDefinitions(false);
-               for(std::vector<class ObjectFile::Atom*>::iterator itr = fAllAtoms.begin(); itr != fAllAtoms.end(); ++itr) {
-                       ObjectFile::Atom *atom = *itr;
-                       ObjectFile::Atom::Scope scope = atom->getScope();
-                       const char* name = atom->getName();
-                       if ( name != NULL ) {
-                               if ( scope == ObjectFile::Atom::scopeGlobal ) {
-                                       // check for globals that are downgraded to hidden
-                                       if ( !fOptions.shouldExport(name) ) {
-                                               atom->setScope(ObjectFile::Atom::scopeLinkageUnit);
-                                               //fprintf(stderr, "demote %s to hidden\n", name);
-                                       }
-                                       else if ( atom->getDefinitionKind() == ObjectFile::Atom::kWeakDefinition ) {
-                                               // we do have an exported weak symbol, turn WEAK_DEFINES back on
-                                               fGlobalSymbolTable.setHasExternalWeakDefinitions(true);
-                                       }
+       // otherwise, create a new final section
+       bool objFile = false;
+       switch ( _options.outputKind() ) {
+               case Options::kStaticExecutable:
+               case Options::kDynamicExecutable:
+               case Options::kDynamicLibrary:
+               case Options::kDynamicBundle:
+               case Options::kDyld:
+               case Options::kKextBundle:
+               case Options::kPreload:
+                       {
+                               // coalesce some sections
+                               const ld::Section& outSect = FinalSection::outputSection(inputSection, _options.mergeZeroFill());
+                               pos = _sectionInToFinalMap.find(&outSect);
+                               if ( pos != _sectionInToFinalMap.end() ) {
+                                       _sectionInToFinalMap[&inputSection] = pos->second;
+                                       //fprintf(stderr, "_sectionInToFinalMap[%p] = %p\n", &inputSection, pos->second);
+                                       return pos->second;
                                }
-                               else if ( scope == ObjectFile::Atom::scopeLinkageUnit ) {
-                                       // check for hiddens that were requested to be exported
-                                       if ( fOptions.hasExportMaskList() && fOptions.shouldExport(name) ) {
-                                               warning("cannot export hidden symbol %s from %s", name, atom->getFile()->getPath());
-                                       }
+                               else if ( outSect != inputSection ) {
+                                       // new output section created, but not in map
+                                       baseForFinalSection = &outSect;
                                }
                        }
-               }
-       }
-       
-       // linking is done, so demote hidden symbols to static
-       if ( (fOptions.outputKind() == Options::kObjectFile) && fOptions.keepPrivateExterns() ) {
-               // ld -r -keep_private_externs does not move hidden symbols to static
-       }
-       else {
-               for(std::vector<class ObjectFile::Atom*>::iterator itr = fAllAtoms.begin(); itr != fAllAtoms.end(); ++itr) {
-                       ObjectFile::Atom *atom = *itr;
-                       // <rdar://problem/4637139> hidden common symbols cannot be demoted to static
-                       if ( (atom->getScope() == ObjectFile::Atom::scopeLinkageUnit) && (atom->getDefinitionKind() != ObjectFile::Atom::kTentativeDefinition) ) {
-                               atom->setScope(ObjectFile::Atom::scopeTranslationUnit);
-                               //fprintf(stderr, "demote %s to static\n", atom->getDisplayName());
+                       break;
+               case Options::kObjectFile:
+                       baseForFinalSection = &FinalSection::objectOutputSection(inputSection, _options.makeTentativeDefinitionsReal());
+                       pos = _sectionInToFinalMap.find(baseForFinalSection);
+                       if ( pos != _sectionInToFinalMap.end() ) {
+                               _sectionInToFinalMap[&inputSection] = pos->second;
+                               //fprintf(stderr, "_sectionInToFinalMap[%p] = %p\n", &inputSection, pos->second);
+                               return pos->second;
                        }
-               }
+                       objFile = true;
+                       break;
        }
+
+       InternalState::FinalSection* result = new InternalState::FinalSection(*baseForFinalSection, 
+                                                                                                                                       _sectionInToFinalMap.size(), objFile);
+       _sectionInToFinalMap[baseForFinalSection] = result;
+       //fprintf(stderr, "_sectionInToFinalMap[%p] = %p\n", baseForFinalSection, result);
+       sections.push_back(result);
+       return result;
 }
 
-void Linker::link()
+
+int InternalState::FinalSection::sectionComparer(const void* l, const void* r)
+{
+       const FinalSection* left  = *(FinalSection**)l;
+       const FinalSection* right = *(FinalSection**)r;
+       if ( left->_segmentOrder != right->_segmentOrder )
+               return (left->_segmentOrder - right->_segmentOrder);
+       return (left->_sectionOrder - right->_sectionOrder);
+}
+
+void InternalState::sortSections()
 {
-       this->buildAtomList();
-       this->loadAndResolve();
-       this->optimize();
-       this->adjustScope();
-       this->checkObjC();
-       this->processDTrace();
-       this->tweakLayout();
-       this->sortSections();
-       this->sortAtoms();
-       this->writeDotOutput();
-       this->collectDebugInfo();
-       this->writeOutput();
-       this->printStatistics();
+       //fprintf(stderr, "UNSORTED final sections:\n");
+       //for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
+       //      fprintf(stderr, "final section %p %s/%s\n", (*it), (*it)->segmentName(), (*it)->sectionName());
+       //}
+       qsort(&sections[0], sections.size(), sizeof(FinalSection*), &InternalState::FinalSection::sectionComparer);
+       //fprintf(stderr, "SORTED final sections:\n");
+       //for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
+       //      fprintf(stderr, "final section %p %s/%s\n", (*it), (*it)->segmentName(), (*it)->sectionName());
+       //}
+       assert((sections[0]->type() == ld::Section::typeMachHeader) 
+               || ((sections[0]->type() == ld::Section::typeFirstSection) && (sections[1]->type() == ld::Section::typeMachHeader))
+               || ((sections[0]->type() == ld::Section::typePageZero) && (sections[1]->type() == ld::Section::typeMachHeader))
+               || ((sections[0]->type() == ld::Section::typePageZero) && (sections[1]->type() == ld::Section::typeFirstSection) && (sections[2]->type() == ld::Section::typeMachHeader)) );
+       
+}
 
-       if ( fOptions.pauseAtEnd() )
-               sleep(10);
+static char* commatize(uint64_t in, char* out)
+{
+       char* result = out;
+       char rawNum[30];
+       sprintf(rawNum, "%llu", in);
+       const int rawNumLen = strlen(rawNum);
+       for(int i=0; i < rawNumLen-1; ++i) {
+               *out++ = rawNum[i];
+               if ( ((rawNumLen-i) % 3) == 1 )
+                       *out++ = ',';
+       }
+       *out++ = rawNum[rawNumLen-1];
+       *out = '\0';
+       return result;
 }
 
-void Linker::printTime(const char* msg, uint64_t partTime, uint64_t totalTime)
+static void printTime(const char* msg, uint64_t partTime, uint64_t totalTime)
 {
        static uint64_t sUnitsPerSecond = 0;
        if ( sUnitsPerSecond == 0 ) {
@@ -771,34 +597,19 @@ void Linker::printTime(const char* msg, uint64_t partTime, uint64_t totalTime)
                uint32_t milliSeconds = milliSecondsTimeTen/10;
                uint32_t percentTimesTen = (partTime*1000)/totalTime;
                uint32_t percent = percentTimesTen/10;
-               fprintf(stderr, "%s: %u.%u milliseconds (%u.%u%%)\n", msg, milliSeconds, milliSecondsTimeTen-milliSeconds*10, percent, percentTimesTen-percent*10);
+               fprintf(stderr, "%24s: % 4d.%d milliseconds (% 4d.%d%%)\n", msg, milliSeconds, milliSecondsTimeTen-milliSeconds*10, percent, percentTimesTen-percent*10);
        }
        else {
                uint32_t secondsTimeTen = (partTime*10)/sUnitsPerSecond;
                uint32_t seconds = secondsTimeTen/10;
                uint32_t percentTimesTen = (partTime*1000)/totalTime;
                uint32_t percent = percentTimesTen/10;
-               fprintf(stderr, "%s: %u.%u seconds (%u.%u%%)\n", msg, seconds, secondsTimeTen-seconds*10, percent, percentTimesTen-percent*10);
+               fprintf(stderr, "%24s: % 4d.%d seconds (% 4d.%d%%)\n", msg, seconds, secondsTimeTen-seconds*10, percent, percentTimesTen-percent*10);
        }
 }
 
-char* Linker::commatize(uint64_t in, char* out)
-{
-       char* result = out;
-       char rawNum[30];
-       sprintf(rawNum, "%llu", in);
-       const int rawNumLen = strlen(rawNum);
-       for(int i=0; i < rawNumLen-1; ++i) {
-               *out++ = rawNum[i];
-               if ( ((rawNumLen-i) % 3) == 1 )
-                       *out++ = ',';
-       }
-       *out++ = rawNum[rawNumLen-1];
-       *out = '\0';
-       return result;
-}
 
-void Linker::getVMInfo(vm_statistics_data_t& info)
+static void getVMInfo(vm_statistics_data_t& info)
 {
        mach_msg_type_number_t count = sizeof(vm_statistics_data_t) / sizeof(natural_t);
        kern_return_t error = host_statistics(mach_host_self(), HOST_VM_INFO,
@@ -808,3270 +619,135 @@ void Linker::getVMInfo(vm_statistics_data_t& info)
        }
 }
 
-void Linker::printStatistics()
+int main(int argc, const char* argv[])
 {
-       fEndTime = mach_absolute_time();
-       if ( fOptions.printStatistics() ) {
-               vm_statistics_data_t endVMInfo;
-               getVMInfo(endVMInfo);
-
-               uint64_t totalTime = fEndTime - fStartTime;
-               printTime("ld total time", totalTime, totalTime);
-               printTime(" option parsing time",       fStartCreateReadersTime -       fStartTime,                                     totalTime);
-               printTime(" object file processing",fStartCreateWriterTime -    fStartCreateReadersTime,        totalTime);
-               printTime(" output file setup",         fStartBuildAtomsTime -          fStartCreateWriterTime,         totalTime);
-               printTime(" build atom list",           fStartLoadAndResolveTime -      fStartBuildAtomsTime,           totalTime);
-               printTime(" resolve references",        fStartSortTime -                        fStartLoadAndResolveTime,       totalTime);
-               printTime(" sort output",                       fStartDebugTime -                       fStartSortTime,                         totalTime);
-               printTime(" process debug info",        fStartWriteTime -                       fStartDebugTime,                        totalTime);
-               printTime(" write output",                      fEndTime -                                      fStartWriteTime,                        totalTime);
-               fprintf(stderr, "pageins=%u, pageouts=%u, faults=%u\n", endVMInfo.pageins-fStartVMInfo.pageins,
-                                                                               endVMInfo.pageouts-fStartVMInfo.pageouts, endVMInfo.faults-fStartVMInfo.faults);
-               char temp[40];
-               fprintf(stderr, "processed %3u object files,  totaling %15s bytes\n", fTotalObjectLoaded, commatize(fTotalObjectSize, temp));
-               fprintf(stderr, "processed %3u archive files, totaling %15s bytes\n", fTotalArchivesLoaded, commatize(fTotalArchiveSize, temp));
-               fprintf(stderr, "processed %3u dylib files\n", fTotalDylibsLoaded);
-               fprintf(stderr, "wrote output file            totaling %15s bytes\n", commatize(fOutputFileSize, temp));
+       const char* archName = NULL;
+       bool showArch = false;
+       bool archInferred = false;
+       try {
+               PerformanceStatistics statistics;
+               statistics.startTool = mach_absolute_time();
+               
+               // create object to track command line arguments
+               Options options(argc, argv);
+               InternalState state(options);
+               
+               // gather vm stats
+               if ( options.printStatistics() )
+                       getVMInfo(statistics.vmStart);
+
+               // update strings for error messages
+               showArch = options.printArchPrefix();
+               archName = options.architectureName();
+               archInferred = (options.architecture() == 0);
+               
+               // open and parse input files
+               statistics.startInputFileProcessing = mach_absolute_time();
+               ld::tool::InputFiles inputFiles(options, &archName);
+               
+               // load and resolve all references
+               statistics.startResolver = mach_absolute_time();
+               ld::tool::Resolver resolver(options, inputFiles, state);
+               resolver.resolve();
+                               
+               // add dylibs used
+               statistics.startDylibs = mach_absolute_time();
+               inputFiles.dylibs(state);
+       
+               // do initial section sorting so passes have rough idea of the layout
+               state.sortSections();
+
+               // run passes
+               statistics.startPasses = mach_absolute_time();
+               ld::passes::objc::doPass(options, state);
+               ld::passes::stubs::doPass(options, state);
+               ld::passes::huge::doPass(options, state);
+               ld::passes::got::doPass(options, state);
+               ld::passes::tlvp::doPass(options, state);
+               ld::passes::dylibs::doPass(options, state);     // must be after stubs and GOT passes
+               ld::passes::order::doPass(options, state);
+               state.markAtomsOrdered();
+               ld::passes::branch_shim::doPass(options, state);        // must be after stubs 
+               ld::passes::branch_island::doPass(options, state);      // must be after stubs and order pass
+               ld::passes::dtrace::doPass(options, state);
+               ld::passes::compact_unwind::doPass(options, state);  // must be after order pass
+               
+               // sort final sections
+               state.sortSections();
+
+               // write output file
+               statistics.startOutput = mach_absolute_time();
+               ld::tool::OutputFile out(options);
+               out.write(state);
+               statistics.startDone = mach_absolute_time();
+               
+               // print statistics
+               //mach_o::relocatable::printCounts();
+               if ( options.printStatistics() ) {
+                       getVMInfo(statistics.vmEnd);
+                       uint64_t totalTime = statistics.startDone - statistics.startTool;
+                       printTime("ld total time", totalTime, totalTime);
+                       printTime(" option parsing time", statistics.startInputFileProcessing  -        statistics.startTool,                           totalTime);
+                       printTime(" object file processing", statistics.startResolver                    -      statistics.startInputFileProcessing,totalTime);
+                       printTime(" resolve symbols", statistics.startDylibs                             -      statistics.startResolver,                       totalTime);
+                       printTime(" build atom list", statistics.startPasses                             -      statistics.startDylibs,                         totalTime);
+                       printTime(" passess", statistics.startOutput                             -      statistics.startPasses,                         totalTime);
+                       printTime(" write output", statistics.startDone                          -      statistics.startOutput,                         totalTime);
+                       fprintf(stderr, "pageins=%u, pageouts=%u, faults=%u\n", 
+                                                               statistics.vmEnd.pageins-statistics.vmStart.pageins,
+                                                               statistics.vmEnd.pageouts-statistics.vmStart.pageouts, 
+                                                               statistics.vmEnd.faults-statistics.vmStart.faults);
+                       char temp[40];
+                       fprintf(stderr, "processed %3u object files,  totaling %15s bytes\n", inputFiles._totalObjectLoaded, commatize(inputFiles._totalObjectSize, temp));
+                       fprintf(stderr, "processed %3u archive files, totaling %15s bytes\n", inputFiles._totalArchivesLoaded, commatize(inputFiles._totalArchiveSize, temp));
+                       fprintf(stderr, "processed %3u dylib files\n", inputFiles._totalDylibsLoaded);
+                       fprintf(stderr, "wrote output file            totaling %15s bytes\n", commatize(out.fileSize(), temp));
+               }
+               // <rdar://problem/6780050> Would like linker warning to be build error.
+               if ( options.errorBecauseOfWarnings() ) {
+                       fprintf(stderr, "ld: fatal warning(s) induced error (-fatal_warnings)\n");
+                       return 1;
+               }
        }
+       catch (const char* msg) {
+               if ( archInferred )
+                       fprintf(stderr, "ld: %s for inferred architecture %s\n", msg, archName);
+               else if ( showArch )
+                       fprintf(stderr, "ld: %s for architecture %s\n", msg, archName);
+               else
+                       fprintf(stderr, "ld: %s\n", msg);
+               return 1;
+       }
+
+       return 0;
 }
 
-inline void Linker::addAtom(ObjectFile::Atom& atom)
+
+#ifndef NDEBUG
+// implement assert() function to print out a backtrace before aborting
+void __assert_rtn(const char* func, const char* file, int line, const char* failedexpr)
 {
-       // add to list of all atoms
-       fAllAtoms.push_back(&atom);
+       fprintf(stderr, "Assertion failed: (%s), function %s, file %s, line %d.\n", failedexpr, func, file, line);
 
-       if ( fOptions.deadStrip() == Options::kDeadStripOff ) {
-               // not dead-stripping code, so add atom's references's names to symbol table as to-be-resolved-later
-               std::vector<class ObjectFile::Reference*>& references = atom.getReferences();
-               for (std::vector<ObjectFile::Reference*>::iterator it=references.begin(); it != references.end(); it++) {
-                       ObjectFile::Reference* reference = *it;
-                       if ( reference->getTargetBinding() == ObjectFile::Reference::kUnboundByName )
-                               fGlobalSymbolTable.require(reference->getTargetName());
-                       if ( reference->getFromTargetBinding() == ObjectFile::Reference::kUnboundByName )
-                               fGlobalSymbolTable.require(reference->getFromTargetName());
+       void* callStack[128];
+       int depth = ::backtrace(callStack, 128);
+       char* buffer = (char*)malloc(1024);
+       for(int i=0; i < depth-1; ++i) {
+               Dl_info info;
+               dladdr(callStack[i], &info);
+               const char* symboName = info.dli_sname;
+               if ( (symboName != NULL) && (strncmp(symboName, "_Z", 2) == 0) ) {
+                       size_t bufLen = 1024;
+                       int result;
+                       char* unmangled = abi::__cxa_demangle(symboName, buffer, &bufLen, &result);
+                       if ( unmangled != NULL )
+                               symboName = unmangled;
                }
-               // update total size info (except for __ZEROPAGE atom)
-               if ( atom.getSegment().isContentReadable() ) {
-                       fTotalSize += atom.getSize();
-                       if ( atom.isZeroFill() )
-                               fTotalZeroFillSize += atom.getSize();
-               }
-       }
-       else {
-               if ( atom.dontDeadStrip() )
-                       fLiveRootAtoms.insert(&atom);
+               long offset = (uintptr_t)callStack[i] - (uintptr_t)info.dli_saddr;
+               fprintf(stderr, "%d  %p  %s + %ld\n", i, callStack[i], symboName, offset);
        }
-
-       // if in global namespace, add atom itself to symbol table
-       ObjectFile::Atom::Scope scope = atom.getScope();
-       const char* name = atom.getName();
-       if ( (scope != ObjectFile::Atom::scopeTranslationUnit) && (name != NULL) ) {
-               // add to symbol table
-               fGlobalSymbolTable.add(atom);
-       }
-
-       // record section orders so output file can have same order
-       if (atom.getSectionName())
-               atom.setSection(Section::find(atom.getSectionName(), atom.getSegment().getName(), atom.isZeroFill()));
-}
-
-
-void Linker::markDead(ObjectFile::Atom* atom)
-{
-       //fprintf(stderr, "markDead(%p) %s from %s\n", atom, atom->getDisplayName(), atom->getFile()->getPath());
-       fDeadAtoms.insert(atom);
-       
-       // <rdar://problem/6578360> -dead_strip inhibits weak coalescing in no_dead_strip section
-       if ( fLiveRootAtoms.count(atom) != 0 ) {
-               fLiveRootAtoms.erase(atom);
-       }
-       
-       //
-       // The kGroupSubordinate reference kind is used to model group comdat.  
-       // The "signature" atom in the group has a kGroupSubordinate reference to
-       // all other members of the group.  So, if the signature atom is 
-       // coalesced away, all other atoms in the group should also be removed.  
-       //
-       std::vector<class ObjectFile::Reference*>& references = atom->getReferences();
-       for (std::vector<ObjectFile::Reference*>::iterator rit=references.begin(); rit != references.end(); rit++) {
-               ObjectFile::Reference* ref = *rit;
-               if ( ref->getKind() == 2 /*kGroupSubordinate*/ ) {      // FIX FIX
-                       ObjectFile::Atom* targetAtom = &(ref->getTarget());
-                       //fprintf(stderr, "  markDead(%p) subordinate %s\n", targetAtom, targetAtom->getDisplayName());
-                       if ( targetAtom == NULL ) {
-                               warning("%s has a group reference to %s but is not bound", atom->getDisplayName(), ref->getTargetName());
-                       }
-                       else {
-                               if ( targetAtom->getScope() != ObjectFile::Atom::scopeTranslationUnit ) {
-                                       // ok for .eh symbols to be not static in -r mode
-                                       if ( (fOptions.outputKind() != Options::kObjectFile) || (strcmp(targetAtom->getSectionName(), "__eh_frame") != 0) )
-                                               warning("%s is in a comdat group but its scope is not static", targetAtom->getDisplayName());
-                               }
-                               this->markDead(targetAtom);
-                       }
-               }
-       }
-}
-
-void Linker::updateConstraints(ObjectFile::Reader* reader)
-{
-       // check objc objects were compiled compatibly
-       ObjectFile::Reader::ObjcConstraint objcAddition = reader->getObjCConstraint();
-       if ( reader->getInstallPath() == NULL ) {
-               // adding a .o file
-               switch ( objcAddition ) {
-                       case ObjectFile::Reader::kObjcNone:
-                               break;
-                       case ObjectFile::Reader::kObjcRetainRelease:
-                               if ( fCurrentObjCConstraint == ObjectFile::Reader::kObjcGC )
-                                       throwf("%s built with incompatible Garbage Collection settings to link with previous .o files", reader->getPath());
-                               fCurrentObjCConstraint = ObjectFile::Reader::kObjcRetainRelease;
-                               break;
-                       case ObjectFile::Reader::kObjcRetainReleaseOrGC:
-                               if ( fCurrentObjCConstraint == ObjectFile::Reader::kObjcNone )
-                                       fCurrentObjCConstraint = ObjectFile::Reader::kObjcRetainReleaseOrGC;
-                               break;
-                       case ObjectFile::Reader::kObjcGC:
-                               if ( fCurrentObjCConstraint == ObjectFile::Reader::kObjcRetainRelease )
-                                       throwf("%s built with incompatible Garbage Collection settings to link with previous .o files", reader->getPath());
-                               fCurrentObjCConstraint = ObjectFile::Reader::kObjcGC;
-                               break;
-               }
-       }
-       if ( reader->objcReplacementClasses() )
-               fObjcReplacmentClasses = true;
-
-       // check cpu sub-types for stricter sub-type
-       fCurrentCpuConstraint = (ObjectFile::Reader::CpuConstraint)reader->updateCpuConstraint(fCurrentCpuConstraint);
-}
-
-inline void Linker::addAtoms(std::vector<class ObjectFile::Atom*>& atoms)
-{
-       bool scanAll = fOptions.readerOptions().fFullyLoadArchives || fOptions.readerOptions().fLoadAllObjcObjectsFromArchives;
-       bool first = true; 
-       for (std::vector<ObjectFile::Atom*>::iterator it=atoms.begin(); it != atoms.end(); it++) {
-               // usually we only need to get the first atom's reader, but
-               // with -all_load all atoms from all .o files come come back together
-               // so we need to scan all atoms
-               if ( first || scanAll ) {
-                       // update fReadersThatHaveSuppliedAtoms
-                       ObjectFile::Reader* reader = (*it)->getFile();
-                       if ( std::find(fReadersThatHaveSuppliedAtoms.begin(), fReadersThatHaveSuppliedAtoms.end(), reader)
-                                       == fReadersThatHaveSuppliedAtoms.end() ) {
-                               fReadersThatHaveSuppliedAtoms.push_back(reader);
-                               updateConstraints(reader);                              
-                       }       
-               }
-               this->addAtom(**it);
-               first = false;
-       }
-}
-
-void Linker::logArchive(ObjectFile::Reader* reader)
-{
-       if ( (fArchiveReaders.count(reader) != 0) && (fArchiveReadersLogged.count(reader) == 0) ) {
-               fArchiveReadersLogged.insert(reader);
-               const char* fullPath = reader->getPath();
-               char realName[MAXPATHLEN];
-               if ( realpath(fullPath, realName) != NULL )
-                       fullPath = realName;
-               logTraceInfo("[Logging for XBS] Used static archive: %s\n", fullPath);
-       }
-}
-
-
-void Linker::buildAtomList()
-{
-       fStartBuildAtomsTime = mach_absolute_time();
-       // add initial undefines from -u option
-       std::vector<const char*>& initialUndefines = fOptions.initialUndefines();
-       for (std::vector<const char*>::iterator it=initialUndefines.begin(); it != initialUndefines.end(); it++) {
-               fGlobalSymbolTable.require(*it);
-       }
-
-       // writer can contribute atoms
-       this->addAtoms(fOutputFile->getAtoms());
-
-       // each reader contributes atoms
-       for (std::vector<class ObjectFile::Reader*>::iterator it=fInputFiles.begin(); it != fInputFiles.end(); it++) {
-               ObjectFile::Reader* reader = *it;
-               std::vector<class ObjectFile::Atom*>& atoms = reader->getAtoms();
-               this->addAtoms(atoms);
-               if ( fOptions.readerOptions().fTraceArchives && (atoms.size() != 0) ) 
-                       logArchive(reader);
-       }
-
-       // extra command line section always at end
-       std::vector<Options::ExtraSection>& extraSections = fOptions.extraSections();
-       for( std::vector<Options::ExtraSection>::iterator it=extraSections.begin(); it != extraSections.end(); ++it) {
-               this->addAtoms((new opaque_section::Reader(it->segmentName, it->sectionName, it->path, it->data, it->dataLen, fNextInputOrdinal))->getAtoms());
-               fNextInputOrdinal += it->dataLen;
-       }
-       
-       // done with all .o files on command line
-       // everything loaded from now on is a just-in-time atom
-       fInitialLoadsDone = true;
-}
-
-static const char* pathLeafName(const char* path)
-{
-       const char* shortPath = strrchr(path, '/');
-       if ( shortPath == NULL )
-               return path;
-       else
-               return &shortPath[1];
-}
-
-
-void Linker::loadUndefines()
-{
-       // keep looping until no more undefines were added in last loop
-       unsigned int undefineCount = 0xFFFFFFFF;
-       while ( undefineCount != fGlobalSymbolTable.getRequireCount() ) {
-               undefineCount = fGlobalSymbolTable.getRequireCount();
-               std::vector<const char*> undefineNames;
-               fGlobalSymbolTable.getUndefinesNames(undefineNames);
-               for(std::vector<const char*>::iterator it = undefineNames.begin(); it != undefineNames.end(); ++it) {
-                       // load for previous undefine may also have loaded this undefine, so check again
-                       if ( fGlobalSymbolTable.find(*it) == NULL ) {
-                               std::vector<class ObjectFile::Atom*>* atoms = this->addJustInTimeAtoms(*it, true, true, true);
-                               if ( atoms != NULL ) 
-                                       delete atoms;
-                       }
-               }
-               // <rdar://problem/5894163> need to search archives for overrides of common symbols 
-               if ( fGlobalSymbolTable.hasExternalTentativeDefinitions() ) {
-                       bool searchDylibs = (fOptions.commonsMode() == Options::kCommonsOverriddenByDylibs);
-                       std::vector<const char*> tentativeDefinitionNames;
-                       fGlobalSymbolTable.getTentativesNames(tentativeDefinitionNames);
-                       for(std::vector<const char*>::iterator it = tentativeDefinitionNames.begin(); it != tentativeDefinitionNames.end(); ++it) {
-                               // load for previous tentative  may also have overridden this tentative, so check again                                                
-                               ObjectFile::Atom* tent = fGlobalSymbolTable.find(*it);
-                               if ( (tent != NULL) && (tent->getDefinitionKind() == ObjectFile::Atom::kTentativeDefinition) ) {
-                                       std::vector<class ObjectFile::Atom*>* atoms = this->addJustInTimeAtoms(*it, searchDylibs, true, false);
-                                       if ( atoms != NULL ) 
-                                               delete atoms;
-                               }
-                       }
-               }
-       }
-}
-
-// temp hack for rdar://problem/4718189 map ObjC class names to new runtime names
-class ExportedObjcClass
-{
-public:
-       ExportedObjcClass(Options& opt) : fOptions(opt)  {}
-
-       bool operator()(const char* name) const {
-               if ( fOptions.shouldExport(name) ) {
-                       if ( strncmp(name, ".objc_class_name_", 17) == 0 )
-                               return true;
-                       if ( strncmp(name, "_OBJC_CLASS_$_", 14) == 0 )
-                               return true;
-                       if ( strncmp(name, "_OBJC_METACLASS_$_", 18) == 0 )
-                               return true;
-               }
-               //fprintf(stderr, "%s is not exported\n", name);
-               return false;
-       }
-private:
-       Options& fOptions;
-};
-
-
-void Linker::checkUndefines()
-{
-       // error out on any remaining undefines
-       bool doPrint = true;
-       bool doError = true;
-       switch ( fOptions.undefinedTreatment() ) {
-               case Options::kUndefinedError:
-                       break;
-               case Options::kUndefinedDynamicLookup:
-                       doError = false;
-                       break;
-               case Options::kUndefinedWarning:
-                       doError = false;
-                       break;
-               case Options::kUndefinedSuppress:
-                       doError = false;
-                       doPrint = false;
-                       break;
-       }
-       std::vector<const char*> unresolvableUndefines;
-       fGlobalSymbolTable.getUndefinesNames(unresolvableUndefines);
-
-       // temp hack for rdar://problem/4718189 map ObjC class names to new runtime names
-       // ignore unresolved references to Objc class names that are listed in -exported_symbols_list
-       if ( fOptions.hasExportRestrictList() )
-               unresolvableUndefines.erase(std::remove_if(unresolvableUndefines.begin(), unresolvableUndefines.end(), ExportedObjcClass(fOptions)), unresolvableUndefines.end());
-
-       const int unresolvableCount = unresolvableUndefines.size();
-       int unresolvableExportsCount  = 0;
-       if ( unresolvableCount != 0 ) {
-               if ( doPrint ) {
-                       if ( fOptions.printArchPrefix() )
-                               fprintf(stderr, "Undefined symbols for architecture %s:\n", fArchitectureName);
-                       else
-                               fprintf(stderr, "Undefined symbols:\n");
-                       for (int i=0; i < unresolvableCount; ++i) {
-                               const char* name = unresolvableUndefines[i];
-                               fprintf(stderr, "  \"%s\", referenced from:\n", name);
-                               // scan all atoms for references
-                               bool foundAtomReference = false;
-                               for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
-                                       ObjectFile::Atom* atom = *it;
-                                       std::vector<class ObjectFile::Reference*>& references = atom->getReferences();
-                                       for (std::vector<ObjectFile::Reference*>::iterator rit=references.begin(); rit != references.end(); rit++) {
-                                               ObjectFile::Reference* reference = *rit;
-                                               if ( reference->getTargetBinding() == ObjectFile::Reference::kUnboundByName ) {
-                                                       if ( strcmp(reference->getTargetName(), name) == 0 ) {
-                                                               fprintf(stderr, "      %s in %s\n", atom->getDisplayName(), pathLeafName(atom->getFile()->getPath()));
-                                                               foundAtomReference = true;
-                                                       }
-                                               }
-                                               if ( reference->getFromTargetBinding() == ObjectFile::Reference::kUnboundByName ) {
-                                                       if ( strcmp(reference->getFromTargetName(), name) == 0 ) {
-                                                               fprintf(stderr, "      %s in %s\n", atom->getDisplayName(), pathLeafName(atom->getFile()->getPath()));
-                                                               foundAtomReference = true;
-                                                       }
-                                               }
-                                       }
-                               }
-                               // scan command line options
-                               if  ( !foundAtomReference && fOptions.hasExportRestrictList() && fOptions.shouldExport(name) ) {
-                                       fprintf(stderr, "     -exported_symbols_list command line option\n");
-                                       ++unresolvableExportsCount;
-                               }
-                       }
-               }
-               if ( doError ) 
-                       throw "symbol(s) not found";
-       }
-       
-       // for each tentative definition in symbol table look for dylib that exports same symbol name
-       if ( fGlobalSymbolTable.hasExternalTentativeDefinitions() ) {
-               for (SymbolTable::Mapper::iterator it=fGlobalSymbolTable.begin(); it != fGlobalSymbolTable.end(); ++it) {
-                       ObjectFile::Atom* atom = it->second;
-                       if ( (atom != NULL) && (atom->getDefinitionKind()==ObjectFile::Atom::kTentativeDefinition) 
-                               && (atom->getScope() == ObjectFile::Atom::scopeGlobal) ) {
-                               // look for dylibs that export same name as used by global tentative definition
-                               addJustInTimeAtoms(atom->getName(), true, false, false);
-                       }
-               }
-       }
-       
-       
-       // record any overrides of weak symbols any linked dylib 
-       for (SymbolTable::Mapper::iterator it=fGlobalSymbolTable.begin(); it != fGlobalSymbolTable.end(); ++it) {
-               ObjectFile::Atom* atom = it->second;
-               if ( (atom != NULL) && (atom->getDefinitionKind()==ObjectFile::Atom::kRegularDefinition) 
-                       && (atom->getScope() == ObjectFile::Atom::scopeGlobal) ) {
-                       const char* name = atom->getName();
-                       //fprintf(stderr, "looking for dylibs with a weak %s\n", name);
-                       // look for dylibs with weak exports of the same name 
-                       for (InstallNameToReader::iterator it=fDylibMap.begin(); it != fDylibMap.end(); it++) {
-                               ObjectFile::Reader* reader = it->second;
-                               if ( reader->hasWeakExternals() ) {
-                                       std::vector<class ObjectFile::Atom*>* dylibAtoms = reader->getJustInTimeAtomsFor(name);
-                                       if ( dylibAtoms != NULL ) {
-                                               //fprintf(stderr, "addJustInTimeAtoms(%s) => found in file %s\n", name, reader->getPath() );
-                                               // if this is a weak definition in a dylib
-                                               if ( (dylibAtoms->at(0)->getDefinitionKind() == ObjectFile::Atom::kExternalWeakDefinition) ) {
-                                                       fRegularDefAtomsThatOverrideADylibsWeakDef.insert(atom);
-                                               }
-                                       }
-                               }
-                       }
-               }
-       }
-       
-}
-
-
-
-std::vector<class ObjectFile::Atom*>* Linker::addJustInTimeAtoms(const char* name, bool searchDylibs, bool searchArchives, bool okToMakeProxy)
-{
-       //fprintf(stderr, "addJustInTimeAtoms(%s, searchDylibs=%d, searchArchives=%d)\n", name, searchDylibs, searchArchives );
-       // when creating final linked image, writer gets first chance
-       if ( fOptions.outputKind() != Options::kObjectFile ) {
-               std::vector<class ObjectFile::Atom*>* atoms = fOutputFile->getJustInTimeAtomsFor(name);
-               if ( atoms != NULL ) {
-                       this->addAtoms(*atoms);
-                       //fprintf(stderr, "addJustInTimeAtoms(%s) => found in file %s\n", name, fOutputFile->getPath() );
-                       return atoms;  // found a definition, no need to search anymore
-               }
-       }
-
-       // give readers a chance
-       for (std::vector<class ObjectFile::Reader*>::iterator it=fInputFiles.begin(); it != fInputFiles.end(); it++) {
-               ObjectFile::Reader* reader = *it;
-               if ( reader != NULL ) {
-                       // if this reader is a static archive that has the symbol we need, pull in all atoms in that module
-                       // if this reader is a dylib that exports the symbol we need, have it synthesize an atom for us.
-                       //fprintf(stderr, "addJustInTimeAtoms(%s), looking in reader %s\n", name, reader->getPath() );
-                       bool isDylibReader = (reader->getInstallPath() != NULL);
-                       if ( isDylibReader ? searchDylibs : searchArchives ) {
-                               std::vector<class ObjectFile::Atom*>* atoms = reader->getJustInTimeAtomsFor(name);
-                               if ( atoms != NULL ) {
-                                       this->addAtoms(*atoms);
-                                       //fprintf(stderr, "addJustInTimeAtoms(%s) => found in file %s\n", name, reader->getPath() );
-                                       if ( !isDylibReader && fOptions.readerOptions().fTraceArchives ) {
-                                               logArchive(reader);
-                                       }
-                                       // if this is a weak definition in a dylib
-                                       if ( isDylibReader && (atoms->size() == 1) && (atoms->at(0)->getDefinitionKind() == ObjectFile::Atom::kExternalWeakDefinition) ) {
-                                               // keep looking for a non-weak definition
-                                       }
-                                       else {
-                                               // found a definition, no need to search anymore
-                                               return atoms;  
-                                       }
-                               }
-                       }
-               }
-       }
-
-       // for two level namesapce, give all implicitly link dylibs a chance
-       if ( fOptions.nameSpace() == Options::kTwoLevelNameSpace ) {
-               for (InstallNameToReader::iterator it=fDylibMap.begin(); it != fDylibMap.end(); it++) {
-                       if ( it->second->implicitlyLinked() ) {
-                               //fprintf(stderr, "addJustInTimeAtoms(%s), looking in implicitly linked %s\n", name, it->second->getPath() );
-                               std::vector<class ObjectFile::Atom*>* atoms = it->second->getJustInTimeAtomsFor(name);
-                               if ( atoms != NULL ) {
-                                       this->addAtoms(*atoms);
-                                       //fprintf(stderr, "addJustInTimeAtoms(%s) => found in file %s\n", name, reader->getPath() );
-                                       // if this is a weak definition in a dylib
-                                       if ( (atoms->size() == 1) && (atoms->at(0)->getDefinitionKind() == ObjectFile::Atom::kExternalWeakDefinition) ) {
-                                               // keep looking for a non-weak definition
-                                       }
-                                       else {
-                                               // found a definition, no need to search anymore
-                                               return atoms;  
-                                       }
-                               }
-                       }
-               }
-       }
-
-       // for flat namespace, give indirect dylibs
-       if ( fOptions.nameSpace() != Options::kTwoLevelNameSpace ) {
-               for (InstallNameToReader::iterator it=fDylibMap.begin(); it != fDylibMap.end(); it++) {
-                       if ( ! it->second->explicitlyLinked() ) {
-                               std::vector<class ObjectFile::Atom*>* atoms = it->second->getJustInTimeAtomsFor(name);
-                               if ( atoms != NULL ) {
-                                       this->addAtoms(*atoms);
-                                       //fprintf(stderr, "addJustInTimeAtoms(%s) => found in file %s\n", name, reader->getPath() );
-                                       return atoms;  // found a definition, no need to search anymore
-                               }
-                       }
-               }
-       }
-
-       // writer creates a proxy in two cases:
-       // 1) ld -r is being used to create a .o file 
-       // 2) -undefined dynamic_lookup is being used
-       // 3) -U _foo is being used
-       // 4) x86_64 kext bundle is being created
-       if (    (fOptions.outputKind() == Options::kObjectFile) 
-               ||  ((fOptions.undefinedTreatment() != Options::kUndefinedError) && okToMakeProxy)
-               ||      (fOptions.someAllowedUndefines() && okToMakeProxy) 
-               ||  (fOptions.outputKind() == Options::kKextBundle) ) {
-               ObjectFile::Atom* atom = fOutputFile->getUndefinedProxyAtom(name);
-               if ( atom != NULL ) {
-                       this->addAtom(*atom);
-                       return NULL;
-               }
-       }
-       //fprintf(stderr, "addJustInTimeAtoms(%s) => not found\n", name);
-       return NULL;
-}
-
-void Linker::resolve(ObjectFile::Reference* reference)
-{
-       // look in global symbol table
-       const char* targetName = reference->getTargetName();
-       ObjectFile::Atom* target = fGlobalSymbolTable.find(targetName);
-       if ( target == NULL ) {
-               throwf("unexpected undefined symbol: %s", targetName);
-       }
-       reference->setTarget(*target, reference->getTargetOffset());
-}
-
-void Linker::resolveFrom(ObjectFile::Reference* reference)
-{
-       // handle references that have two (from and to) targets
-       const char* fromTargetName = reference->getFromTargetName();
-       ObjectFile::Atom* fromTarget = fGlobalSymbolTable.find(fromTargetName);
-       if ( fromTarget == NULL ) {
-               throwf("unexpected undefined symbol: %s", fromTargetName);
-       }
-       reference->setFromTarget(*fromTarget);
-}
-
-
-void Linker::resolveReferences()
-{
-       // note: the atom list may grow during this loop as libraries supply needed atoms
-       for (unsigned int j=0; j < fAllAtoms.size(); ++j) {
-               ObjectFile::Atom* atom = fAllAtoms[j];
-               std::vector<class ObjectFile::Reference*>& references = atom->getReferences();
-               for (std::vector<ObjectFile::Reference*>::iterator it=references.begin(); it != references.end(); it++) {
-                       ObjectFile::Reference* reference = *it;
-                       if ( reference->getTargetBinding() == ObjectFile::Reference::kUnboundByName )
-                               this->resolve(reference);
-                       if ( reference->getFromTargetBinding() == ObjectFile::Reference::kUnboundByName )
-                               this->resolveFrom(reference);
-               }
-       }
-}
-
-
-// used to remove stabs associated with atoms that won't be in output file
-class NotInSet
-{
-public:
-       NotInSet(std::set<ObjectFile::Atom*>& theSet) : fSet(theSet) {}
-
-       bool operator()(const ObjectFile::Reader::Stab& stab) const {
-               if ( stab.atom == NULL )
-                       return false;   // leave stabs that are not associated with any atome
-               else
-                       return ( fSet.count(stab.atom) == 0 );
-       }
-
-private:
-       std::set<ObjectFile::Atom*>& fSet;
-};
-
-
-class NotLive
-{
-public:
-       NotLive(std::set<ObjectFile::Atom*>& set) : fLiveAtoms(set)  {}
-
-       bool operator()(ObjectFile::Atom*& atom) const {
-               //if ( fLiveAtoms.count(atom) == 0 )
-               //      fprintf(stderr, "dead strip %s\n", atom->getDisplayName());
-               return ( fLiveAtoms.count(atom) == 0 );
-       }
-private:
-       std::set<ObjectFile::Atom*>& fLiveAtoms;
-};
-
-
-void Linker::addJustInTimeAtomsAndMarkLive(const char* name)
-{
-       //fprintf(stderr, "addJustInTimeAtomsAndMarkLive(%s)\n", name);
-       std::vector<class ObjectFile::Atom*>* atoms = this->addJustInTimeAtoms(name, true, true, true);
-       if ( atoms != NULL ) {
-               if ( fOptions.allGlobalsAreDeadStripRoots() ) {
-                       for (std::vector<ObjectFile::Atom*>::iterator it=atoms->begin(); it != atoms->end(); it++) {
-                               ObjectFile::Atom* atom = *it;
-                               if ( atom->getScope() ==  ObjectFile::Atom::scopeGlobal ) {
-                                       WhyLiveBackChain rootChain;
-                                       rootChain.previous = NULL;
-                                       rootChain.referer = atom;
-                                       this->markLive(*atom, &rootChain);
-                               }
-                       }
-               }
-               delete atoms;
-       }
-}
-
-void Linker::markLive(ObjectFile::Atom& atom, struct Linker::WhyLiveBackChain* previous)
-{
-       //fprintf(stderr, "markLive(%p)\n", &atom);
-       if ( fLiveAtoms.count(&atom) == 0 ) {
-               // if -why_live cares about this symbol, then dump chain
-               if ( (previous->referer != NULL) && fOptions.printWhyLive(previous->referer->getDisplayName()) ) {
-                       int depth = 0;
-                       for(WhyLiveBackChain* p = previous; p != NULL; p = p->previous, ++depth) {
-                               for(int i=depth; i > 0; --i)
-                                       fprintf(stderr, "  ");
-                               fprintf(stderr, "%p %s from %s\n", p->referer, p->referer->getDisplayName(), p->referer->getFile()->getPath());
-                       }
-               }
-               // set up next chain
-               WhyLiveBackChain thisChain;
-               thisChain.previous = previous;
-               // this atom is live
-               fLiveAtoms.insert(&atom);
-               // update total size info (except for __ZEROPAGE atom)
-               if ( atom.getSegment().isContentReadable() ) {
-                       fTotalSize += atom.getSize();
-                       if ( atom.isZeroFill() )
-                               fTotalZeroFillSize += atom.getSize();
-               }
-               // and all atoms it references
-               std::vector<class ObjectFile::Reference*>& references = atom.getReferences();
-               for (std::vector<ObjectFile::Reference*>::iterator it=references.begin(); it != references.end(); it++) {
-                       ObjectFile::Reference* reference = *it;
-                       if ( reference->getTargetBinding() == ObjectFile::Reference::kUnboundByName ) {
-                               // look in global symbol table
-                               const char* targetName = reference->getTargetName();
-                               ObjectFile::Atom* target = fGlobalSymbolTable.find(targetName);
-                               if ( (target == NULL) || (target->getDefinitionKind() == ObjectFile::Atom::kTentativeDefinition) ) {
-                                       // load archives or dylibs
-                                       this->addJustInTimeAtomsAndMarkLive(targetName);
-                               }
-                               // look again
-                               target = fGlobalSymbolTable.find(targetName);
-                               if ( target != NULL ) {
-                                       reference->setTarget(*target, reference->getTargetOffset());
-                               }
-                               else {
-                                       // mark as undefined, for later error processing
-                                       fAtomsWithUnresolvedReferences.push_back(&atom);
-                                       fGlobalSymbolTable.require(targetName);
-                               }
-                       }
-                       switch ( reference->getTargetBinding() ) {
-                               case ObjectFile::Reference::kBoundDirectly:
-                               case ObjectFile::Reference::kBoundByName:
-                                       thisChain.referer = &reference->getTarget();
-                                       markLive(reference->getTarget(), &thisChain);
-                                       break;
-                               case ObjectFile::Reference::kDontBind:
-                               case ObjectFile::Reference::kUnboundByName:
-                                       // do nothing
-                                       break;
-                       }
-                       // do the same as above, for "from target"
-                       if ( reference->getFromTargetBinding() == ObjectFile::Reference::kUnboundByName ) {
-                               // look in global symbol table
-                               const char* targetName = reference->getFromTargetName();
-                               ObjectFile::Atom* target = fGlobalSymbolTable.find(targetName);
-                               if ( (target == NULL) || (target->getDefinitionKind() == ObjectFile::Atom::kTentativeDefinition) ) {
-                                       // load archives or dylibs
-                                       this->addJustInTimeAtomsAndMarkLive(targetName);
-                               }
-                               // look again
-                               target = fGlobalSymbolTable.find(targetName);
-                               if ( target != NULL ) {
-                                       reference->setFromTarget(*target);
-                               }
-                               else {
-                                       // mark as undefined, for later error processing
-                                       fGlobalSymbolTable.require(targetName);
-                               }
-                       }
-                       switch ( reference->getFromTargetBinding() ) {
-                               case ObjectFile::Reference::kBoundDirectly:
-                               case ObjectFile::Reference::kBoundByName:
-                                       thisChain.referer = &reference->getFromTarget();
-                                       markLive(reference->getFromTarget(), &thisChain);
-                                       break;
-                               case ObjectFile::Reference::kUnboundByName:
-                               case ObjectFile::Reference::kDontBind:
-                                       // do nothing
-                                       break;
-                       }
-               }
-       }
-}
-
-
-void Linker::addLiveRoot(const char* name)
-{
-       ObjectFile::Atom* target = fGlobalSymbolTable.find(name);
-       if ( target == NULL ) {
-               this->addJustInTimeAtomsAndMarkLive(name);
-               target = fGlobalSymbolTable.find(name);
-       }
-       if ( target != NULL )
-               fLiveRootAtoms.insert(target);
-}
-
-void Linker::moveToFrontOfSection(ObjectFile::Atom* atom)
-{
-       // check if already moved to front
-       if ( fInitializerAtoms.find(atom) == fInitializerAtoms.end() ) {
-               // don't re-order initializers from .o files without MH_SUBSECTIONS_VIA_SYMBOLS
-               // since that could make all atoms in the file look like initializers 
-               if ( atom->getFile()->canScatterAtoms() ) {
-                       //fprintf(stdout, "marking as initializer: %s\n", atom->getDisplayName());
-                       fInitializerAtoms.insert(atom);
-                       // mark all functions that this function references
-                       std::vector<class ObjectFile::Reference*>& references = atom->getReferences();
-                       for (std::vector<ObjectFile::Reference*>::const_iterator rit=references.begin(); rit != references.end(); rit++) {
-                               ObjectFile::Atom* childAtom = &((*rit)->getTarget());
-                               if ( childAtom != NULL ) {
-                                       if ( (*rit)->isBranch() ) {
-                                               this->moveToFrontOfSection(childAtom);
-                                       }
-                                       else if ( (childAtom->getName() != NULL) && (strncmp(childAtom->getName(), "___tcf_", 7) == 0) ) {
-                                               //fprintf(stdout, "marking as terminator: %s\n", childAtom->getDisplayName());
-                                               fTerminatorAtoms.insert(childAtom);
-                                       }
-                               }
-                       }
-               }
-       }
-}
-
-void Linker::deadStripResolve()
-{
-       // add main() to live roots
-       ObjectFile::Atom* entryPoint = this->entryPoint(false);
-       if ( entryPoint != NULL )
-               fLiveRootAtoms.insert(entryPoint);
-
-       // add dyld_stub_binding_helper/dyld_stub_binder to live roots
-       ObjectFile::Atom* dyldHelper = this->dyldClassicHelper();
-       if ( dyldHelper != NULL )
-               fLiveRootAtoms.insert(dyldHelper);
-       dyldHelper = this->dyldCompressedHelper();
-       if ( dyldHelper != NULL )
-               fLiveRootAtoms.insert(dyldHelper);
-
-       // if using lazy dylib loading, add dyld_lazy_dylib_stub_binding_helper() to live roots
-       if ( fOptions.usingLazyDylibLinking() ) {
-               ObjectFile::Atom* dyldLazyDylibHelper = this->dyldLazyLibraryHelper();
-               if ( dyldLazyDylibHelper != NULL )
-                       fLiveRootAtoms.insert(dyldLazyDylibHelper);
-       }
-       
-       // add -exported_symbols_list, -init, and -u entries to live roots
-       std::vector<const char*>& initialUndefines = fOptions.initialUndefines();
-       for (std::vector<const char*>::iterator it=initialUndefines.begin(); it != initialUndefines.end(); it++)
-               addLiveRoot(*it);
-
-       // if -exported_symbols_list that has wildcards, we need to find all matches and make them the roots 
-       // <rdar://problem/5524973>
-       if ( fOptions.hasWildCardExportRestrictList() ) {
-               for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
-                       ObjectFile::Atom* atom = *it;
-                       if ( (atom->getScope() == ObjectFile::Atom::scopeGlobal) 
-                               && (fDeadAtoms.count(atom) == 0) 
-                               && fOptions.shouldExport(atom->getName()) )
-                                       fLiveRootAtoms.insert(atom);
-               }
-       }
-
-       // in some cases, every global scope atom in initial .o files is a root
-       if ( fOptions.allGlobalsAreDeadStripRoots() ) {
-               for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
-                       ObjectFile::Atom* atom = *it;
-                       if ( (atom->getScope() == ObjectFile::Atom::scopeGlobal) && (fDeadAtoms.count(atom) == 0) )
-                               fLiveRootAtoms.insert(atom);
-               }
-       }
-
-       // mark all roots as live, and all atoms they reference
-       for (std::set<ObjectFile::Atom*>::iterator it=fLiveRootAtoms.begin(); it != fLiveRootAtoms.end(); it++) {
-               WhyLiveBackChain rootChain;
-               rootChain.previous = NULL;
-               rootChain.referer = *it;
-               markLive(**it, &rootChain);
-       }
-
-       // it is possible that there are unresolved references that can be resolved now
-       // this can happen if the first reference to a common symbol in an archive.
-       // common symbols are not in the archive TOC, but the .o could have been pulled in later.
-       // <rdar://problem/4654131> ld64 while linking cc1 [ when dead_strip is ON]
-       for (std::vector<ObjectFile::Atom*>::iterator it=fAtomsWithUnresolvedReferences.begin(); it != fAtomsWithUnresolvedReferences.end(); it++) {
-               std::vector<class ObjectFile::Reference*>& references = (*it)->getReferences();
-               for (std::vector<ObjectFile::Reference*>::iterator rit=references.begin(); rit != references.end(); rit++) {
-                       ObjectFile::Reference* reference = *rit;
-                       if ( reference->getTargetBinding() == ObjectFile::Reference::kUnboundByName ) {
-                               ObjectFile::Atom* target = fGlobalSymbolTable.find(reference->getTargetName());
-                               if ( target != NULL ) {
-                                       reference->setTarget(*target, reference->getTargetOffset());
-                                       fLiveAtoms.insert(target);
-                                       // by just adding this atom to fLiveAtoms set, we are assuming it has no
-                                       // references, which is true for commons.
-                                       if ( target->getDefinitionKind() != ObjectFile::Atom::kTentativeDefinition )
-                                               warning("internal error %s is not a tentative definition", target->getDisplayName());
-                               }
-                       }
-                       if ( reference->getFromTargetBinding() == ObjectFile::Reference::kUnboundByName ) {
-                               ObjectFile::Atom* target = fGlobalSymbolTable.find(reference->getFromTargetName());
-                               if ( target != NULL ) {
-                                       reference->setFromTarget(*target);
-                                       fLiveAtoms.insert(target);
-                                       // by just adding this atom to fLiveAtoms set, we are assuming it has no
-                                       // references, which is true for commons.
-                                       if ( target->getDefinitionKind() != ObjectFile::Atom::kTentativeDefinition )
-                                               warning("internal error %s is not a tentative definition", target->getDisplayName());
-                               }
-                       }
-               }
-       }
-
-       // It is possible that some weak symbols were overridden by lazily load objects from archives
-       // and we have some atoms that still refer to the overridden ones.
-       // In that case we need to go back and rebind
-       if ( fAtomsOverriddenByLateLoads.size() > 0 ) {
-               for (std::set<ObjectFile::Atom*>::iterator it=fLiveAtoms.begin(); it != fLiveAtoms.end(); ++it) {
-                       ObjectFile::Atom* atom = *it;
-                       std::vector<class ObjectFile::Reference*>& references = atom->getReferences();
-                       for (std::vector<ObjectFile::Reference*>::iterator rit=references.begin(); rit != references.end(); ++rit) {
-                               ObjectFile::Reference* reference = *rit;
-                               ObjectFile::Atom* toTarget = &reference->getTarget();
-                               if ( fAtomsOverriddenByLateLoads.count(toTarget) ) {
-                                       //fprintf(stderr, "change reference in %p from %p to %p\n", atom, toTarget, fGlobalSymbolTable.find(toTarget->getName()));
-                                       reference->setTarget(*fGlobalSymbolTable.find(toTarget->getName()), reference->getTargetOffset());
-                               }
-                               ObjectFile::Atom* fromTarget = &reference->getFromTarget();
-                               if ( (fromTarget != NULL) && fAtomsOverriddenByLateLoads.count(fromTarget) ) {
-                                       //fprintf(stderr, "change from reference in %p from %p to %p\n", atom, fromTarget, fGlobalSymbolTable.find(fromTarget->getName()));
-                                       reference->setTarget(*fGlobalSymbolTable.find(fromTarget->getName()), reference->getFromTargetOffset());
-                               }
-                       }
-               }
-
-               // make sure overriders are live if the atom they overrid was live
-               for (std::set<ObjectFile::Atom*>::iterator it=fAtomsOverriddenByLateLoads.begin(); it != fAtomsOverriddenByLateLoads.end(); ++it) {
-                       ObjectFile::Atom* overriderAtom = *it;
-                       if ( fLiveAtoms.count(overriderAtom) ) {
-                               WhyLiveBackChain rootChain;
-                               rootChain.previous = NULL;
-                               rootChain.referer = *it;
-                               markLive(*fGlobalSymbolTable.find(overriderAtom->getName()), &rootChain);
-                       }
-               }
-
-               // remove overridden atoms from fLiveAtoms
-               fAllAtoms.erase(std::remove_if(fAllAtoms.begin(), fAllAtoms.end(), InSet(fAtomsOverriddenByLateLoads)), fAllAtoms.end());
-               fAtomsOverriddenByLateLoads.clear();
-               // remove dead atoms from fLiveAtoms
-               fAllAtoms.erase(std::remove_if(fAllAtoms.begin(), fAllAtoms.end(), InSet(fDeadAtoms)), fAllAtoms.end());
-       }
-       
-       // now remove all non-live atoms from fAllAtoms
-       fAllAtoms.erase(std::remove_if(fAllAtoms.begin(), fAllAtoms.end(), NotLive(fLiveAtoms)), fAllAtoms.end());
-}
-
-void Linker::checkObjC()
-{
-       // check dylibs
-       switch ( fCurrentObjCConstraint ) {
-               case ObjectFile::Reader::kObjcNone:
-                       // can link against any dylib
-                       break;
-               case ObjectFile::Reader::kObjcRetainRelease:
-                       // cannot link against GC-only dylibs
-                       for (InstallNameToReader::iterator it=fDylibMap.begin(); it != fDylibMap.end(); it++) {
-                               if ( it->second->explicitlyLinked() ) {
-                                       if ( it->second->getObjCConstraint() == ObjectFile::Reader::kObjcGC )
-                                               throwf("this linkage unit uses Retain/Release.  It cannot link against the GC-only dylib: %s", it->second->getPath());
-                               }
-                       }
-                       break;
-               case ObjectFile::Reader::kObjcRetainReleaseOrGC:
-                       // can link against GC or RR dylibs
-                       break;
-               case ObjectFile::Reader::kObjcGC:
-                       // cannot link against RR-only dylibs
-                       for (InstallNameToReader::iterator it=fDylibMap.begin(); it != fDylibMap.end(); it++) {
-                               if ( it->second->explicitlyLinked() ) {
-                                       if ( it->second->getObjCConstraint() == ObjectFile::Reader::kObjcRetainRelease )
-                                               throwf("this linkage unit requires GC.  It cannot link against Retain/Release dylib: %s", it->second->getPath());
-                               }
-                       }
-                       break;
-       }
-       
-       // synthesize __OBJC __image_info atom if needed
-       if ( fCurrentObjCConstraint != ObjectFile::Reader::kObjcNone ) {
-               this->addAtom(fOutputFile->makeObjcInfoAtom(fCurrentObjCConstraint, fObjcReplacmentClasses));
-       }
-}
-
-
-static uint8_t pcRelKind(cpu_type_t arch)
-{
-       switch ( arch ) {
-               case CPU_TYPE_POWERPC:
-                       return ppc::kPointerDiff32;
-               case CPU_TYPE_POWERPC64:
-                       return ppc64::kPointerDiff32;
-               case CPU_TYPE_I386:
-                       return x86::kPointerDiff;
-               case CPU_TYPE_X86_64:
-                       return x86_64::kPointerDiff32;
-               case CPU_TYPE_ARM:
-                       return arm::kPointerDiff;
-       }
-       throw "uknown architecture";
-}
-
-typedef uint8_t* (*oldcreatedof_func_t) (const char*, cpu_type_t, unsigned int, const char*[], const char*[], uint64_t offsetsInDOF[], size_t* size);
-typedef uint8_t* (*createdof_func_t)(cpu_type_t, unsigned int, const char*[], unsigned int, const char*[], const char*[], uint64_t offsetsInDOF[], size_t* size);
-
-
-void Linker::processDTrace()
-{
-       // only make __dof section in final linked images
-       if ( fOptions.outputKind() == Options::kObjectFile )
-               return;
-
-       // scan all atoms looking for dtrace probes
-       std::vector<DTraceProbeInfo>                                            probeSites;
-       std::vector<DTraceProbeInfo>                                            isEnabledSites;
-       std::map<const ObjectFile::Atom*,CStringSet>            atomToDtraceTypes;
-       for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); ++it) {
-               ObjectFile::Atom* atom = *it;
-               std::vector<class ObjectFile::Reference*>& references = atom->getReferences();
-               for (std::vector<ObjectFile::Reference*>::iterator rit=references.begin(); rit != references.end(); ++rit) {
-                       ObjectFile::Reference* ref = *rit;
-                       if ( ref->getTargetBinding() == ObjectFile::Reference::kDontBind ) {
-                               const char* probeName = ref->getTargetName();
-                               if ( probeName != NULL ) {
-                                       uint32_t offsetInAtom = ref->getFixUpOffset();
-                                       if ( strncmp(probeName, "___dtrace_probe$", 16) == 0 ) 
-                                               probeSites.push_back(DTraceProbeInfo(atom, offsetInAtom, probeName));
-                                       else if ( strncmp(probeName, "___dtrace_isenabled$", 20) == 0 ) 
-                                               isEnabledSites.push_back(DTraceProbeInfo(atom, offsetInAtom, probeName));
-                                       else if ( strncmp(probeName, "___dtrace_", 10) == 0 )
-                                               atomToDtraceTypes[atom].insert(probeName);
-                               }
-                       }
-               }
-       }
-
-       // if no probes, we're done
-       if ( (probeSites.size() == 0) && (isEnabledSites.size() == 0) ) 
-               return;
-       
-       // partition probes by provider name
-       // The symbol names looks like:
-       //      "___dtrace_probe$" provider-name "$" probe-name [ "$"... ]
-       //      "___dtrace_isenabled$" provider-name "$" probe-name [ "$"... ]
-       ProviderToProbes providerToProbes;
-       std::vector<DTraceProbeInfo> emptyList;
-       for(std::vector<DTraceProbeInfo>::iterator it = probeSites.begin(); it != probeSites.end(); ++it) {
-               // ignore probes in functions that were coalesed away rdar://problem/5628149
-               if ( fDeadAtoms.count((ObjectFile::Atom*)(it->atom)) == 0 ) {
-                       const char* providerStart = &it->probeName[16];
-                       const char* providerEnd = strchr(providerStart, '$');
-                       if ( providerEnd != NULL ) {
-                               char providerName[providerEnd-providerStart+1];
-                               strlcpy(providerName, providerStart, providerEnd-providerStart+1);
-                               ProviderToProbes::iterator pos = providerToProbes.find(providerName);
-                               if ( pos == providerToProbes.end() ) {
-                                       const char* dup = strdup(providerName);
-                                       providerToProbes[dup] = emptyList;
-                               }
-                               providerToProbes[providerName].push_back(*it);
-                       }
-               }
-       }
-       for(std::vector<DTraceProbeInfo>::iterator it = isEnabledSites.begin(); it != isEnabledSites.end(); ++it) {
-               // ignore probes in functions that were coalesed away rdar://problem/5628149
-               if ( fDeadAtoms.count((ObjectFile::Atom*)(it->atom)) == 0 ) {
-                       const char* providerStart = &it->probeName[20];
-                       const char* providerEnd = strchr(providerStart, '$');
-                       if ( providerEnd != NULL ) {
-                               char providerName[providerEnd-providerStart+1];
-                               strlcpy(providerName, providerStart, providerEnd-providerStart+1);
-                               ProviderToProbes::iterator pos = providerToProbes.find(providerName);
-                               if ( pos == providerToProbes.end() ) {
-                                       const char* dup = strdup(providerName);
-                                       providerToProbes[dup] = emptyList;
-                               }
-                               providerToProbes[providerName].push_back(*it);
-                       }
-               }
-       }
-       
-       // create a DOF section for each provider
-       int dofIndex=1;
-       CStringSet sectionNamesUsed;
-       for(ProviderToProbes::iterator pit = providerToProbes.begin(); pit != providerToProbes.end(); ++pit, ++dofIndex) {
-               const char* providerName = pit->first;
-               const std::vector<DTraceProbeInfo>& probes = pit->second;
-
-               // open library and find dtrace_create_dof()
-               void* handle = dlopen("/usr/lib/libdtrace.dylib", RTLD_LAZY);
-               if ( handle == NULL )
-                       throwf("couldn't dlopen() /usr/lib/libdtrace.dylib: %s", dlerror());
-               createdof_func_t pCreateDOF = (createdof_func_t)dlsym(handle, "dtrace_ld_create_dof");
-               if ( pCreateDOF == NULL )
-                       throwf("couldn't find \"dtrace_ld_create_dof\" in /usr/lib/libdtrace.dylib: %s", dlerror());
-               // build list of typedefs/stability infos for this provider
-               CStringSet types;
-               for(std::vector<DTraceProbeInfo>::const_iterator it = probes.begin(); it != probes.end(); ++it) {
-                       std::map<const ObjectFile::Atom*,CStringSet>::iterator pos = atomToDtraceTypes.find(it->atom);
-                       if ( pos != atomToDtraceTypes.end() ) {
-                               for(CStringSet::iterator sit = pos->second.begin(); sit != pos->second.end(); ++sit) {
-                                       const char* providerStart = strchr(*sit, '$')+1;
-                                       const char* providerEnd = strchr(providerStart, '$');
-                                       if ( providerEnd != NULL ) {
-                                               char aProviderName[providerEnd-providerStart+1];
-                                               strlcpy(aProviderName, providerStart, providerEnd-providerStart+1);
-                                               if ( strcmp(aProviderName, providerName) == 0 )
-                                                       types.insert(*sit);
-                                       }
-                               }
-                       }
-               }
-               int typeCount = types.size();
-               const char* typeNames[typeCount];
-               //fprintf(stderr, "types for %s:\n", providerName);
-               uint32_t index = 0;
-               for(CStringSet::iterator it = types.begin(); it != types.end(); ++it) {
-                       typeNames[index] = *it;
-                       //fprintf(stderr, "\t%s\n", *it);
-                       ++index;
-               }
-               
-               // build list of probe/isenabled sites
-               const uint32_t probeCount = probes.size();
-               const char* probeNames[probeCount];
-               const char* funtionNames[probeCount];
-               uint64_t offsetsInDOF[probeCount];
-               index = 0;
-               for(std::vector<DTraceProbeInfo>::const_iterator it = probes.begin(); it != probes.end(); ++it) {
-                       probeNames[index] = it->probeName;
-                       funtionNames[index] = it->atom->getName();
-                       offsetsInDOF[index] = 0;
-                       ++index;
-               }
-               //fprintf(stderr, "calling libtrace to create DOF\n");
-               //for(uint32_t i=0; i < probeCount; ++i) 
-               //      fprintf(stderr, "  [%u]\t %s\t%s\n", i, probeNames[i], funtionNames[i]);
-               // call dtrace library to create DOF section
-               size_t dofSectionSize;
-               uint8_t* p = (*pCreateDOF)(fArchitecture, typeCount, typeNames, probeCount, probeNames, funtionNames, offsetsInDOF, &dofSectionSize);
-               if ( p != NULL ) {
-                       char sectionName[18];
-                       strcpy(sectionName, "__dof_");
-                       strlcpy(&sectionName[6], providerName, 10);
-                       // create unique section name so each DOF is in its own section
-                       if ( sectionNamesUsed.count(sectionName) != 0 ) {
-                               sectionName[15] = '0';
-                               sectionName[16] = '\0';
-                               while ( sectionNamesUsed.count(sectionName) != 0 )
-                                       ++sectionName[15];
-                       }
-                       sectionNamesUsed.insert(sectionName);
-                       char symbolName[strlen(providerName)+64];
-                       sprintf(symbolName, "__dtrace_dof_for_provider_%s", providerName);
-                       opaque_section::Reader* reader = new opaque_section::Reader("__TEXT", sectionName, 
-                                                                                                       "dtrace", p, dofSectionSize, fNextInputOrdinal, symbolName);
-                       fNextInputOrdinal += dofSectionSize;
-                       // add references
-                       for (uint32_t i=0; i < probeCount; ++i) {
-                               uint64_t offset = offsetsInDOF[i];
-                               //fprintf(stderr, "%s offset[%d]=0x%08llX\n", providerName, i, offset);
-                               if ( offset > dofSectionSize )
-                                       throwf("offsetsInDOF[i]=%0llX > dofSectionSize=%0lX\n", i, offset, dofSectionSize);
-                               reader->addSectionReference(pcRelKind(fArchitecture), offset, probes[i].atom, probes[i].offset, reader->getAtoms()[0], 0);
-                       }
-                       this->addAtoms(reader->getAtoms());
-               }
-               else {
-                       throw "error creating dtrace DOF section";
-               }
-       }
-}
-
-
-static bool matchesObjectFile(ObjectFile::Atom* atom, const char* objectFileLeafName)
-{
-       if ( objectFileLeafName == NULL )
-               return true;
-       const char* atomFullPath = atom->getFile()->getPath();
-       const char* lastSlash = strrchr(atomFullPath, '/');
-       if ( lastSlash != NULL ) {
-               if ( strcmp(&lastSlash[1], objectFileLeafName) == 0 )
-                       return true;
-       }
-       else {
-               if ( strcmp(atomFullPath, objectFileLeafName) == 0 )
-                       return true;
-       }
-       return false;
-}
-
-
-static bool usesAnonymousNamespace(const char* symbol)
-{
-       return ( (strncmp(symbol, "__Z", 3) == 0) && (strstr(symbol, "_GLOBAL__N_") != NULL) );
-}
-
-
-//
-//  convert:
-//             __ZN20_GLOBAL__N__Z5main2v3barEv                                        =>  _ZN-3barEv
-//             __ZN37_GLOBAL__N_main.cxx_00000000_493A01A33barEv       =>  _ZN-3barEv
-//
-static void canonicalizeAnonymousName(const char* inSymbol, char outSymbol[])
-{
-       const char* globPtr = strstr(inSymbol, "_GLOBAL__N_");
-       while ( isdigit(*(--globPtr)) )
-               ; // loop
-       char* endptr;
-       unsigned long length = strtoul(globPtr+1, &endptr, 10);
-       const char* globEndPtr = endptr + length;
-       int startLen = globPtr-inSymbol+1;
-       memcpy(outSymbol, inSymbol, startLen);
-       outSymbol[startLen] = '-';
-       strcpy(&outSymbol[startLen+1], globEndPtr);
-}
-
-
-ObjectFile::Atom* Linker::findAtom(const Options::OrderedSymbol& orderedSymbol)
-{
-       ObjectFile::Atom* atom = fGlobalSymbolTable.find(orderedSymbol.symbolName);
-       if ( atom != NULL ) {
-               if ( matchesObjectFile(atom, orderedSymbol.objectFileName) )
-                       return atom;
-       }
-       else {
-               // slow case.  The requested symbol is not in symbol table, so might be static function
-               static SymbolTable::Mapper hashTableOfTranslationUnitScopedSymbols;
-               static SymbolTable::Mapper hashTableOfSymbolsWithAnonymousNamespace;
-               static bool built = false;
-               // build a hash_map the first time
-               if ( !built ) {
-                       for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
-                               atom = *it;
-                               const char* name = atom->getName();
-                               if ( name != NULL) {
-                                       if ( usesAnonymousNamespace(name) ) {
-                                               // symbol that uses anonymous namespace
-                                               char canonicalName[strlen(name)+2];
-                                               canonicalizeAnonymousName(name, canonicalName);
-                                               const char* hashName = strdup(canonicalName);
-                                               SymbolTable::Mapper::iterator pos = hashTableOfSymbolsWithAnonymousNamespace.find(hashName);
-                                               if ( pos == hashTableOfSymbolsWithAnonymousNamespace.end() )
-                                                       hashTableOfSymbolsWithAnonymousNamespace[hashName] = atom;
-                                               else
-                                                       hashTableOfSymbolsWithAnonymousNamespace[hashName] = NULL;      // collision, denote with NULL
-                                       }
-                                       else if ( atom->getScope() == ObjectFile::Atom::scopeTranslationUnit ) {
-                                               // static function or data
-                                               SymbolTable::Mapper::iterator pos = hashTableOfTranslationUnitScopedSymbols.find(name);
-                                               if ( pos == hashTableOfTranslationUnitScopedSymbols.end() )
-                                                       hashTableOfTranslationUnitScopedSymbols[name] = atom;
-                                               else
-                                                       hashTableOfTranslationUnitScopedSymbols[name] = NULL;   // collision, denote with NULL
-                                       }
-                               }
-                       }
-                       //fprintf(stderr, "built hash table of %lu static functions\n", hashTableOfTranslationUnitScopedSymbols.size());
-                       built = true;
-               }
-
-               // look for name in hashTableOfTranslationUnitScopedSymbols
-               SymbolTable::Mapper::iterator pos = hashTableOfTranslationUnitScopedSymbols.find(orderedSymbol.symbolName);
-               if ( pos != hashTableOfTranslationUnitScopedSymbols.end() ) {
-                       if ( (pos->second != NULL) && matchesObjectFile(pos->second, orderedSymbol.objectFileName) ) {
-                               //fprintf(stderr, "found %s in hash table\n", orderedSymbol.symbolName);
-                               return pos->second;
-                       }
-                       if ( pos->second == NULL )
-                       // name is in hash table, but atom is NULL, so that means there are duplicates, so we use super slow way
-                       for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
-                               atom = *it;
-                               if ( atom->getScope() == ObjectFile::Atom::scopeTranslationUnit ) {
-                                       const char* name = atom->getName();
-                                       if ( (name != NULL) && (strcmp(name, orderedSymbol.symbolName) == 0) ) {
-                                               if ( matchesObjectFile(atom, orderedSymbol.objectFileName) ) {
-                                                       if ( fOptions.printOrderFileStatistics() )
-                                                               warning("%s specified in order_file but it exists in multiple .o files. "
-                                                                               "Prefix symbol with .o filename in order_file to disambiguate", orderedSymbol.symbolName);
-                                                       return atom;
-                                               }
-                                       }
-                               }
-                       }
-               }
-               
-               // look for name in hashTableOfSymbolsWithAnonymousNamespace
-               if ( usesAnonymousNamespace(orderedSymbol.symbolName) ) {
-                       // symbol that uses anonymous namespace
-                       char canonicalName[strlen(orderedSymbol.symbolName)+2];
-                       canonicalizeAnonymousName(orderedSymbol.symbolName, canonicalName);
-                       SymbolTable::Mapper::iterator pos = hashTableOfSymbolsWithAnonymousNamespace.find(canonicalName);
-                       if ( pos != hashTableOfSymbolsWithAnonymousNamespace.end() ) {
-                               if ( (pos->second != NULL) && matchesObjectFile(pos->second, orderedSymbol.objectFileName) ) {
-                                       //fprintf(stderr, "found %s in anonymous namespace hash table\n", canonicalName);
-                                       return pos->second;
-                               }
-                               if ( pos->second == NULL )
-                               // name is in hash table, but atom is NULL, so that means there are duplicates, so we use super slow way
-                               for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
-                                       atom = *it;
-                                       const char* name = atom->getName();
-                                       if ( (name != NULL) && usesAnonymousNamespace(name) ) {
-                                               char canonicalAtomName[strlen(name)+2];
-                                               canonicalizeAnonymousName(name, canonicalAtomName);
-                                               if ( strcmp(canonicalAtomName, canonicalName) == 0 ) {
-                                                       if ( matchesObjectFile(atom, orderedSymbol.objectFileName) ) {
-                                                               if ( fOptions.printOrderFileStatistics() )
-                                                                       warning("%s specified in order_file but it exists in multiple .o files. "
-                                                                               "Prefix symbol with .o filename in order_file to disambiguate", orderedSymbol.symbolName);
-                                                               return atom;
-                                                       }
-                                               }
-                                       }
-                               }
-                       }
-               }
-       }
-       return NULL;
-}
-
-
-void Linker::sortSections()
-{
-       Section::assignIndexes();
-}
-
-
-//
-// Linker::sortAtoms()
-//
-// The purpose of this method is to take the graph of all Atoms and produce an ordered
-// sequence of atoms.  The constraints are that: 1) all Atoms of the same Segment must
-// be contiguous, 2)  all Atoms of the same Section must be contigous, 3) Atoms specified
-// in an order_file are seqenced as in the order_file and before Atoms not specified,
-// 4) Atoms in the same section from the same .o file should be contiguous and sequenced
-// in the same order they were in the .o file, 5) Atoms in the same Section but which came
-// from different .o files should be sequenced in the same order that the .o files
-// were passed to the linker (i.e. command line order).
-//
-// The way this is implemented is that the linker passes a "base ordinal" to each Reader
-// as it is constructed.  The reader should construct it Atoms so that calling getOrdinal()
-// on its atoms returns a contiguous range of values starting at the base ordinal.  Then
-// sorting is just sorting by section, then by ordinal.
-//
-// If an order_file is specified, it gets more complicated.  First, an override-ordinal map
-// is created.  It causes the sort routine to ignore the value returned by getOrdinal() and
-// use the override value instead.  Next some Atoms must be layed out consecutively
-// (e.g. hand written assembly that does not end with return, but rather falls into
-// the next label).  This is modeled in Readers via a "kFollowOn" reference.  The use of
-// kFollowOn refernces produces "clusters" of atoms that must stay together.
-// If an order_file tries to move one atom, it may need to move a whole cluster.  The
-// algorithm to do this models clusters using two maps.  The "starts" maps maps any
-// atom in a cluster to the first Atom in the cluster.  The "nexts" maps an Atom in a
-// cluster to the next Atom in the cluster.  With this in place, while processing an
-// order_file, if any entry is in a cluster (in "starts" map), then the entire cluster is
-// given ordinal overrides.
-//
-void Linker::sortAtoms()
-{
-       fStartSortTime = mach_absolute_time();
-       // if -order_file is used, build map of atom ordinal overrides
-       std::map<const ObjectFile::Atom*, uint32_t>* ordinalOverrideMap = NULL;
-       std::map<const ObjectFile::Atom*, uint32_t> theOrdinalOverrideMap;
-       const bool log = false;
-       if ( fOptions.orderedSymbols().size() != 0 ) {
-               // first make a pass to find all follow-on references and build start/next maps
-               // which are a way to represent clusters of atoms that must layout together
-               std::map<const ObjectFile::Atom*, const ObjectFile::Atom*> followOnStarts;
-               std::map<const ObjectFile::Atom*, const ObjectFile::Atom*> followOnNexts;
-               for (std::vector<ObjectFile::Atom*>::iterator ait=fAllAtoms.begin(); ait != fAllAtoms.end(); ait++) {
-                       ObjectFile::Atom* atom = *ait;
-                       std::vector<class ObjectFile::Reference*>& references = atom->getReferences();
-                       for (std::vector<ObjectFile::Reference*>::iterator rit=references.begin(); rit != references.end(); rit++) {
-                               ObjectFile::Reference* ref = *rit;
-                               if ( ref->getKind() == 1 ) {    // FIX FIX
-                                       ObjectFile::Atom* targetAtom = &ref->getTarget();
-                                       if ( log ) fprintf(stderr, "ref %s -> %s", atom->getDisplayName(), targetAtom->getDisplayName());
-                                       std::map<const ObjectFile::Atom*, const ObjectFile::Atom*>::iterator startFrom = followOnStarts.find(atom);
-                                       std::map<const ObjectFile::Atom*, const ObjectFile::Atom*>::iterator startTo = followOnStarts.find(targetAtom);
-                                       if ( (startFrom == followOnStarts.end()) && (startTo == followOnStarts.end()) ) {
-                                               // this is first time we've seen either atom, make simple cluster of the two
-                                               if ( log ) fprintf(stderr, "  new cluster\n");
-                                               followOnStarts[atom] = atom;
-                                               followOnStarts[targetAtom] = atom;
-                                               followOnNexts[atom] = targetAtom;
-                                               followOnNexts[targetAtom] = NULL;
-                                       }
-                                       else if ( (startFrom != followOnStarts.end()) && (startTo == followOnStarts.end()) && (followOnNexts[atom] == NULL) ) {
-                                               // atom is at end of an existing cluster, so append target to end of cluster
-                                               if ( log ) fprintf(stderr, "  end of cluster starting with %s\n", followOnStarts[atom]->getDisplayName());
-                                               followOnNexts[atom] = targetAtom;
-                                               followOnNexts[targetAtom] = NULL;
-                                               followOnStarts[targetAtom] = followOnStarts[atom];
-                                       }
-                                       else {
-                                               // gerneral case of inserting into an existing cluster
-                                               if ( followOnNexts[atom] != NULL ) {
-                                                       // an atom with two follow-ons is illegal
-                                                       warning("can't order %s because both %s and %s must follow it",
-                                                                               atom->getDisplayName(), targetAtom->getDisplayName(), followOnNexts[atom]->getDisplayName());
-                                               }
-                                               else {
-                                                       // there already exists an atom that says target must be its follow-on
-                                                       const ObjectFile::Atom* originalStart = startTo->second;
-                                                       const ObjectFile::Atom* originalPrevious = originalStart;
-                                                       while ( followOnNexts[originalPrevious] != targetAtom )
-                                                               originalPrevious = followOnNexts[originalPrevious];
-                                                       bool otherIsAlias = (originalPrevious->getSize() == 0);
-                                                       bool thisIsAlias = (atom->getSize() == 0);
-                                                       if ( !otherIsAlias && !thisIsAlias ) {
-                                                               warning("can't order %s because both %s and %s must preceed it",
-                                                                                       targetAtom->getDisplayName(), originalPrevious->getDisplayName(), atom->getDisplayName());
-                                                       }
-                                                       else if ( otherIsAlias ) {
-                                                               if ( originalPrevious == originalStart ) {
-                                                                       // other is alias at start of cluster, make this the new start of cluster
-                                                                       if ( log ) fprintf(stderr, "  becomes new start of cluster previous starting with %s\n", originalStart->getDisplayName());
-                                                                       followOnNexts[atom] = originalPrevious;
-                                                                       for(const ObjectFile::Atom* nextAtom = atom; nextAtom != NULL; nextAtom = followOnNexts[nextAtom])
-                                                                               followOnStarts[nextAtom] = atom;
-                                                               }
-                                                               else {
-                                                                       // other is alias in middle of cluster, insert new atom before it
-                                                                       if ( log ) fprintf(stderr, "  insert into cluster starting with %s before alias %s\n", originalStart->getDisplayName(), originalPrevious->getDisplayName());
-                                                                       followOnStarts[atom] = originalStart;
-                                                                       followOnNexts[atom] = originalPrevious;
-                                                                       for(const ObjectFile::Atom* a = originalStart; a != NULL; a = followOnNexts[a]) {
-                                                                               if ( followOnNexts[a] == originalPrevious ) {
-                                                                                       followOnNexts[a] = atom;
-                                                                                       break;
-                                                                               }
-                                                                       }
-                                                               }
-                                                       }
-                                                       else {
-                                                               // this is alias, so it can go inbetween originalPrevious and targetAtom
-                                                               if ( log ) fprintf(stderr, "  insert into cluster starting with %s after %s\n", originalStart->getDisplayName(), originalPrevious->getDisplayName());
-                                                               followOnStarts[atom] = originalStart;
-                                                               followOnNexts[atom] = followOnNexts[originalPrevious];
-                                                               followOnNexts[originalPrevious] = atom;
-                                                       }
-                                               }
-                                       }
-                               }
-                       }
-               }
-
-               if ( log ) {
-                       for(std::map<const ObjectFile::Atom*, const ObjectFile::Atom*>::iterator it = followOnStarts.begin(); it != followOnStarts.end(); ++it)
-                               fprintf(stderr, "start %s -> %s\n", it->first->getDisplayName(), it->second->getDisplayName());
-
-                       for(std::map<const ObjectFile::Atom*, const ObjectFile::Atom*>::iterator it = followOnNexts.begin(); it != followOnNexts.end(); ++it)
-                               fprintf(stderr, "next %s -> %s\n", it->first->getDisplayName(), (it->second != NULL) ? it->second->getDisplayName() : "null");
-               }
-
-               // with the start/next maps of follow-on atoms we can process the order file and produce override ordinals
-               ordinalOverrideMap = &theOrdinalOverrideMap;
-               uint32_t index = 0;
-               uint32_t matchCount = 0;
-               std::vector<Options::OrderedSymbol>& orderedSymbols = fOptions.orderedSymbols();
-               for(std::vector<Options::OrderedSymbol>::iterator it = orderedSymbols.begin(); it != orderedSymbols.end(); ++it) {
-                       ObjectFile::Atom* atom = this->findAtom(*it);
-                       if ( atom != NULL ) {
-                               std::map<const ObjectFile::Atom*, const ObjectFile::Atom*>::iterator start = followOnStarts.find(atom);
-                               if ( start != followOnStarts.end() ) {
-                                       // this symbol for the order file corresponds to an atom that is in a cluster that must lay out together
-                                       for(const ObjectFile::Atom* nextAtom = start->second; nextAtom != NULL; nextAtom = followOnNexts[nextAtom]) {
-                                               std::map<const ObjectFile::Atom*, uint32_t>::iterator pos = theOrdinalOverrideMap.find(nextAtom);
-                                               if ( pos == theOrdinalOverrideMap.end() ) {
-                                                       theOrdinalOverrideMap[nextAtom] = index++;
-                                                       if (log ) fprintf(stderr, "override ordinal %u assigned to %s in cluster from %s\n", index, nextAtom->getDisplayName(), nextAtom->getFile()->getPath());
-                                               }
-                                               else {
-                                                       if (log ) fprintf(stderr, "could not order %s as %u because it was already laid out earlier by %s as %u\n",
-                                                                                       atom->getDisplayName(), index, followOnStarts[atom]->getDisplayName(), theOrdinalOverrideMap[atom] );
-                                               }
-                                       }
-                               }
-                               else {
-                                       theOrdinalOverrideMap[atom] = index;
-                                       if (log ) fprintf(stderr, "override ordinal %u assigned to %s from %s\n", index, atom->getDisplayName(), atom->getFile()->getPath());
-                               }
-                       }
-                       else {
-                               ++matchCount;
-                               //fprintf(stderr, "can't find match for order_file entry %s/%s\n", it->objectFileName, it->symbolName);
-                       }
-                        ++index;
-               }
-               if ( fOptions.printOrderFileStatistics() && (fOptions.orderedSymbols().size() != matchCount) ) {
-                       warning("only %u out of %lu order_file symbols were applicable", matchCount, fOptions.orderedSymbols().size() );
-               }
-       }
-
-       // sort atoms
-       std::sort(fAllAtoms.begin(), fAllAtoms.end(), Linker::AtomSorter(ordinalOverrideMap, fInitializerAtoms, fTerminatorAtoms));
-
-       //fprintf(stderr, "Sorted atoms:\n");
-       //for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
-       //      fprintf(stderr, "\t%p, %u  %s\t%s\n", (*it)->getSection(), (*it)->getSection()->getIndex(), (*it)->getDisplayName(), (*it)->getFile()->getPath());
-       //}
-}
-
-
-// make sure given addresses are within reach of branches, etc
-void Linker::tweakLayout()
-{
-       // > 2GB images need their large zero fill atoms sorted to the end to keep access with +/- 2GB
-       if ( fTotalSize > 0x7F000000 ) {
-               fBiggerThanTwoGigOutput = true;
-
-               if ( (fTotalSize-fTotalZeroFillSize) > 0x7F000000 )
-                       throwf("total output size exceeds 2GB (%lldMB)", (fTotalSize-fTotalZeroFillSize)/(1024*1024));          
-
-               // move very large (>1MB) zero fill atoms to a new section at very end of __DATA segment
-               Section* hugeZeroFills = Section::find("__huge", "__DATA", true);
-               for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
-                       ObjectFile::Atom* atom = *it;
-                       if ( atom->isZeroFill() && (atom->getSize() > 1024*1024) && (strcmp(atom->getSegment().getName(), "__DATA") == 0) )
-                               atom->setSection(hugeZeroFills);
-               }
-       }
-       
-       // move all initializers to start of __text section
-       if ( fOptions.readerOptions().fAutoOrderInitializers ) {
-               // move -init function to front of __text
-               if ( fOptions.initFunctionName() != NULL ) {
-                       ObjectFile::Atom* initAtom = fGlobalSymbolTable.find(fOptions.initFunctionName());
-                       if ( initAtom == NULL )
-                               throwf("could not find -init function: \"%s\"", fOptions.initFunctionName());
-                       moveToFrontOfSection(initAtom);
-               }
-               
-               // move all functions pointed to by __mod_init_func section to front of __text
-               Section* initSection = Section::find("__mod_init_func", "__DATA", false, false);
-               if ( initSection != NULL ) {
-                       for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); ++it) {
-                               if ( (*it)->getSection() == initSection ) {
-                                       std::vector<class ObjectFile::Reference*>& references = (*it)->getReferences();
-                                       if ( references.size() == 1 ) 
-                                               moveToFrontOfSection(&(references[0]->getTarget()));
-                               }
-                       }
-               }
-       }
-       
-       // move atoms with relocations to start of __DATA,__data section
-       // <rdar://problem/6061558> linker should order __DATA segment to reduce dyld dirtied pages
-       if ( fOptions.orderData() ) {
-               bool slideable = false;
-               switch ( fOptions.outputKind() ) {
-                       case Options::kDynamicExecutable:
-                       case Options::kStaticExecutable:
-                       case Options::kDyld:
-                       case Options::kPreload:
-                       case Options::kObjectFile:
-                       case Options::kKextBundle:
-                               slideable = false;
-                               break;
-                       case Options::kDynamicLibrary:
-                       case Options::kDynamicBundle:
-                               slideable = true;
-                               break;
-               }
-               const bool hasPreferredLoadAddress = (fOptions.baseAddress() != 0);
-               Section* dataSection = Section::find("__data", "__DATA", false, false);
-               if ( dataSection != NULL ) {
-                       for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); ++it) {
-                               ObjectFile::Atom* dataAtom = *it;
-                               if ( dataAtom->getSection() == dataSection ) {
-                                       std::vector<class ObjectFile::Reference*>& references = dataAtom->getReferences();
-                                       if ( references.size() > 0 ) {
-                                               if ( slideable && !hasPreferredLoadAddress ) {
-                                                       // in a slidable image dyld will need to rebase and bind so any references will need runtime fixups
-                                                       // if image has preferred base address, assume it will load there and not rebase
-                                                       moveToFrontOfSection(dataAtom);
-                                               }
-                                               else {
-                                                       // in a non-slideable image, dyld will only do binding, so only references to
-                                                       // symbols in another dylib will need runtime fixups
-                                                       //fprintf(stderr, "reference from atom %s\n", dataAtom->getDisplayName());
-                                                       for (std::vector<ObjectFile::Reference*>::iterator rit=references.begin(); rit != references.end(); rit++) {
-                                                               ObjectFile::Reference* reference = *rit;
-                                                               //fprintf(stderr, "\t%d %s\n", reference->getTarget().getDefinitionKind(), reference->getTarget().getDisplayName());
-                                                               if ( (reference->getTarget().getDefinitionKind() == ObjectFile::Atom::kExternalDefinition)
-                                                                 || (reference->getTarget().getDefinitionKind() == ObjectFile::Atom::kExternalWeakDefinition) ) {
-                                                                       moveToFrontOfSection(dataAtom);
-                                                                       break;
-                                                               }
-                                                       }
-                                               }
-                                       }
-                               }
-                       }
-               }
-       }
-       
-}
-
-
-void Linker::writeDotOutput()
-{
-       const char* dotOutFilePath = fOptions.dotOutputFile();
-       if ( dotOutFilePath != NULL ) {
-               FILE* out = fopen(dotOutFilePath, "w");
-               if ( out != NULL ) {
-                       // print header
-                       fprintf(out, "digraph dg\n{\n");
-                       fprintf(out, "\tconcentrate = true;\n");
-                       fprintf(out, "\trankdir = LR;\n");
-
-                       // print each atom as a node
-                       for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
-                               ObjectFile::Atom* atom = *it;
-                               if ( atom->getFile() != fOutputFile ) {
-                                       const char* name = atom->getDisplayName();
-                                       if ( (atom->getDefinitionKind() == ObjectFile::Atom::kExternalDefinition)
-                                         || (atom->getDefinitionKind() == ObjectFile::Atom::kExternalWeakDefinition) ) {
-                                               fprintf(out, "\taddr%p [ shape = plaintext, label = \"%s\" ];\n", atom, name);
-                                       }
-                                       else if ( strcmp(atom->getSectionName(), "__cstring") == 0 ) {
-                                               char cstring[atom->getSize()+2];
-                                               atom->copyRawContent((uint8_t*)cstring);
-                                               fprintf(out, "\taddr%p [ label = \"string: '", atom);
-                                               for (const char* s=cstring; *s != '\0'; ++s) {
-                                                       if ( *s == '\n' )
-                                                               fprintf(out, "\\\\n");
-                                                       else
-                                                               fputc(*s, out);
-                                               }
-                                               fprintf(out, "'\" ];\n");
-                                       }
-                                       else {
-                                               fprintf(out, "\taddr%p [ label = \"%s\" ];\n", atom, name);
-                                       }
-                               }
-                       }
-                       fprintf(out, "\n");
-
-                       // print each reference as an edge
-                       for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
-                               ObjectFile::Atom* fromAtom = *it;
-                               if ( fromAtom->getFile() != fOutputFile ) {
-                                       std::vector<ObjectFile::Reference*>&  references = fromAtom->getReferences();
-                                       std::set<ObjectFile::Atom*> seenTargets;
-                                       for (std::vector<ObjectFile::Reference*>::iterator rit=references.begin(); rit != references.end(); rit++) {
-                                               ObjectFile::Reference* reference = *rit;
-                                               ObjectFile::Atom* toAtom = &(reference->getTarget());
-                                               if ( seenTargets.count(toAtom) == 0 ) {
-                                                       seenTargets.insert(toAtom);
-                                                       fprintf(out, "\taddr%p -> addr%p;\n", fromAtom, toAtom);
-                                               }
-                                       }
-                               }
-                       }
-                       fprintf(out, "\n");
-
-                       // push all imports to bottom of graph
-                       fprintf(out, "{ rank = same; ");
-                       for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
-                               ObjectFile::Atom* atom = *it;
-                               if ( atom->getFile() != fOutputFile )
-                                       if ( (atom->getDefinitionKind() == ObjectFile::Atom::kExternalDefinition)
-                                         || (atom->getDefinitionKind() == ObjectFile::Atom::kExternalWeakDefinition) ) {
-                                               fprintf(out, "addr%p; ", atom);
-                                       }
-                       }
-                       fprintf(out, "};\n ");
-
-                       // print footer
-                       fprintf(out, "}\n");
-                       fclose(out);
-               }
-               else {
-                       warning("could not write dot output file: %s", dotOutFilePath);
-               }
-       }
-}
-
-ObjectFile::Atom* Linker::entryPoint(bool orInit)
-{
-       // if main executable, find entry point atom
-       ObjectFile::Atom* entryPoint = NULL;
-       switch ( fOptions.outputKind() ) {
-               case Options::kDynamicExecutable:
-               case Options::kStaticExecutable:
-               case Options::kDyld:
-               case Options::kPreload:
-                       entryPoint = fGlobalSymbolTable.find(fOptions.entryName());
-                       if ( entryPoint == NULL ) {
-                               throwf("could not find entry point \"%s\" (perhaps missing crt1.o)", fOptions.entryName());
-                       }
-                       break;
-               case Options::kDynamicLibrary:
-                       if ( orInit && (fOptions.initFunctionName() != NULL) ) {
-                               entryPoint = fGlobalSymbolTable.find(fOptions.initFunctionName());
-                               if ( entryPoint == NULL ) {
-                                       throwf("could not find -init function: \"%s\"", fOptions.initFunctionName());
-                               }
-                       }
-                       break;
-               case Options::kObjectFile:
-               case Options::kDynamicBundle:
-               case Options::kKextBundle:
-                       entryPoint = NULL;
-                       break;
-       }
-       return entryPoint;
-}
-
-ObjectFile::Atom* Linker::dyldClassicHelper()
-{
-       if ( fOptions.makeClassicDyldInfo() )
-               return fGlobalSymbolTable.find("dyld_stub_binding_helper"); 
-       else
-               return NULL;
-}
-
-ObjectFile::Atom* Linker::dyldCompressedHelper()
-{
-       if ( fOptions.makeCompressedDyldInfo() ) {
-               // dyld_stub_binder is in libSystem.B.dylib 
-               ObjectFile::Atom* atom = fGlobalSymbolTable.find("dyld_stub_binder"); 
-               if ( atom == NULL ) {
-                       this->addJustInTimeAtoms("dyld_stub_binder", true, false, true);
-               }
-               atom = fGlobalSymbolTable.find("dyld_stub_binder");
-               return atom;
-       }
-       else
-               return NULL;
-}
-
-ObjectFile::Atom* Linker::dyldLazyLibraryHelper()
-{
-       return fGlobalSymbolTable.find("dyld_lazy_dylib_stub_binding_helper");
-}
-
-const char* Linker::assureFullPath(const char* path)
-{
-       if ( path[0] == '/' )
-               return path;
-       char cwdbuff[MAXPATHLEN];
-       if ( getcwd(cwdbuff, MAXPATHLEN) != NULL ) {
-               char* result;
-               asprintf(&result, "%s/%s", cwdbuff, path);
-               if ( result != NULL )
-                       return result;
-       }
-       return path;
-}
-
-
-//
-// The stab strings are of the form:
-//             <name> ':' <type-code> <number-pari>
-//  but the <name> contain a colon.
-//  For C++ <name> may contain a double colon (e.g. std::string:f(0,1) )
-//  For Objective-C name may contain a colon instead square bracket (e.g. [Foo doit:]:f(0,1) )
-//
-const char* Linker::truncateStabString(const char* str)
-{
-       enum { start, inObjc } state = start;
-       for (const char* s = str; *s != 0; ++s) {
-               char c = *s;
-               switch (state) {
-                       case start:
-                               if ( c == '[' ) {
-                                       state = inObjc;
-                               }
-                               else {
-                                       if ( c == ':' ) {
-                                               if ( s[1] == ':' ) {
-                                                       ++s;
-                                               }
-                                               else {
-                                                       // found colon
-                                                       // Duplicate strndup behavior here.
-                                                       int trunStrLen = s-str+2;
-                                                       char* temp = new char[trunStrLen+1];
-                                                       memcpy(temp, str, trunStrLen);
-                                                       temp[trunStrLen] = '\0';
-                                                       return temp;
-                                               }
-                                       }
-                               }
-                               break;
-                       case inObjc:
-                               if ( c == ']' ) {
-                                       state = start;
-                               }
-                               break;
-               }
-       }
-       // malformed
-       return str;
-}
-
-
-bool Linker::minimizeStab(ObjectFile::Reader::Stab& stab)
-{
-       switch(stab.type){
-               case N_GSYM:
-               case N_STSYM:
-               case N_LCSYM:
-               case N_FUN:
-                       // these all need truncated strings
-                       stab.string = truncateStabString(stab.string);
-                       return true;
-               case N_SO:
-               case N_OSO:
-               case N_OPT:
-               case N_SOL:
-                       // these are included in the minimal stabs, but they keep their full string
-                       return true;
-               default:
-                       return false;
-       }
-}
-
-
-struct HeaderRange {
-       std::vector<ObjectFile::Reader::Stab>::iterator begin;
-       std::vector<ObjectFile::Reader::Stab>::iterator end;
-       int                                                                                             parentRangeIndex;
-       uint32_t                                                                                sum;
-       bool                                                                                    sumPrecomputed;
-       bool                                                                                    useEXCL;
-       bool                                                                                    cannotEXCL; // because of SLINE, etc stabs
-};
-
-
-typedef __gnu_cxx::hash_map<const char*, std::vector<uint32_t>, __gnu_cxx::hash<const char*>, CStringEquals> PathToSums;
-
-// hash table that maps header path to a vector of known checksums for that path
-static PathToSums sKnownBINCLs;
-
-
-void Linker::collectStabs(ObjectFile::Reader* reader, std::map<const class ObjectFile::Atom*, uint32_t>& atomOrdinals)
-{
-       const bool log = false;
-       bool minimal = ( fOptions.readerOptions().fDebugInfoStripping == ObjectFile::ReaderOptions::kDebugInfoMinimal );
-       std::vector<class ObjectFile::Reader::Stab>* readerStabs = reader->getStabs();
-       if ( readerStabs == NULL )
-               return;
-
-       if ( log ) fprintf(stderr, "processesing %lu stabs for %s\n", readerStabs->size(), reader->getPath());
-       std::vector<HeaderRange> ranges;
-       int curRangeIndex = -1;
-       int count = 0;
-       ObjectFile::Atom* atomWithLowestOrdinal = NULL;
-       ObjectFile::Atom* atomWithHighestOrdinal = NULL;
-       uint32_t highestOrdinal = 0;
-       uint32_t lowestOrdinal = UINT_MAX;
-       std::vector<std::pair<ObjectFile::Atom*,ObjectFile::Atom*> > soRanges;
-       // 1) find all (possibly nested) BINCL/EINCL ranges and their checksums
-       // 2) find all SO/SO ranges and the first/last atom own by a FUN stab therein
-       for(std::vector<class ObjectFile::Reader::Stab>::iterator it=readerStabs->begin(); it != readerStabs->end(); ++it) {
-               ++count;
-               switch ( it->type ) {
-                       case N_BINCL:
-                               {
-                                       HeaderRange range;
-                                       range.begin = it;
-                                       range.end = readerStabs->end();
-                                       range.parentRangeIndex = curRangeIndex;
-                                       range.sum = it->value;
-                                       range.sumPrecomputed = (range.sum != 0);
-                                       range.useEXCL = false;
-                                       range.cannotEXCL = false;
-                                       curRangeIndex = ranges.size();
-                                       if ( log ) fprintf(stderr, "[%d]BINCL %s\n", curRangeIndex, it->string);
-                                       ranges.push_back(range);
-                               }
-                               break;
-                       case N_EINCL:
-                               if ( curRangeIndex == -1 ) {
-                                       warning("EINCL missing BINCL in %s", reader->getPath());
-                               }
-                               else {
-                                       ranges[curRangeIndex].end = it+1;
-                                       if ( log ) fprintf(stderr, "[%d->%d]EINCL %s\n", curRangeIndex, ranges[curRangeIndex].parentRangeIndex, it->string);
-                                       curRangeIndex = ranges[curRangeIndex].parentRangeIndex;
-                               }
-                               break;
-                       case N_FUN:
-                               {
-                                       std::map<const class ObjectFile::Atom*, uint32_t>::iterator pos = atomOrdinals.find(it->atom);
-                                       if ( pos != atomOrdinals.end() ) {
-                                               uint32_t ordinal = pos->second;
-                                               if ( ordinal > highestOrdinal ) {
-                                                       highestOrdinal = ordinal;
-                                                       atomWithHighestOrdinal = it->atom;
-                                               }
-                                               if ( ordinal < lowestOrdinal ) {
-                                                       lowestOrdinal = ordinal;
-                                                       atomWithLowestOrdinal = it->atom;
-                                               }
-                                       }
-                               }
-                               // fall through
-                       case N_BNSYM:
-                       case N_ENSYM:
-                       case N_LBRAC:
-                       case N_RBRAC:
-                       case N_SLINE:
-                       case N_STSYM:
-                       case N_LCSYM:
-                               if ( curRangeIndex != -1 ) {
-                                       ranges[curRangeIndex].cannotEXCL = true;
-                                       if ( fOptions.warnStabs() )
-                                               warning("cannot do BINCL/EINCL optimzation because of stabs kinds in %s for %s\n", ranges[curRangeIndex].begin->string, reader->getPath());
-                               }
-                               break;
-                       case N_SO:
-                               if ( (it->string != NULL) && (strlen(it->string) > 0) ) {
-                                       // start SO, reset hi/low FUN tracking
-                                       atomWithLowestOrdinal = NULL;
-                                       atomWithHighestOrdinal = NULL;
-                                       highestOrdinal = 0;
-                                       lowestOrdinal = UINT_MAX;
-                               }
-                               else {
-                                       // end SO, record hi/low atoms for this SO range
-                                       soRanges.push_back(std::make_pair<ObjectFile::Atom*,ObjectFile::Atom*>(atomWithLowestOrdinal, atomWithHighestOrdinal));
-                               }
-                               // fall through
-                       default:
-                               if ( curRangeIndex != -1 ) {
-                                       if ( ! ranges[curRangeIndex].sumPrecomputed ) {
-                                               uint32_t sum = 0;
-                                               const char* s = it->string;
-                                               char c;
-                                               while ( (c = *s++) != 0 ) {
-                                                       sum += c;
-                                                       // don't checkusm first number (file index) after open paren in string
-                                                       if ( c == '(' ) {
-                                                               while(isdigit(*s))
-                                                                       ++s;
-                                                       }
-                                               }
-                                               ranges[curRangeIndex].sum += sum;
-                                       }
-                               }
-
-               }
-       }
-       if ( log ) fprintf(stderr, "processesed %d stabs for %s\n", count, reader->getPath());
-       if ( curRangeIndex != -1 )
-               warning("BINCL (%s) missing EINCL in %s", ranges[curRangeIndex].begin->string, reader->getPath());
-
-       // if no BINCLs
-       if ( ranges.size() == 0 ) {
-               unsigned int soIndex = 0;
-               for(std::vector<ObjectFile::Reader::Stab>::iterator it=readerStabs->begin(); it != readerStabs->end(); ++it) {
-                       // copy minimal or all stabs
-                       ObjectFile::Reader::Stab stab = *it;
-                       if ( !minimal || minimizeStab(stab) ) {
-                               if ( stab.type == N_SO ) {
-                                       if ( soIndex < soRanges.size() ) {
-                                               if ( (stab.string != NULL) && (strlen(stab.string) > 0) ) {
-                                                       // starting SO is associated with first atom
-                                                       stab.atom = soRanges[soIndex].first;
-                                               }
-                                               else {
-                                                       // ending SO is associated with last atom
-                                                       stab.atom = soRanges[soIndex].second;
-                                                       ++soIndex;
-                                               }
-                                       }
-                               }
-                               fStabs.push_back(stab);
-                       }
-               }
-               return;
-       }
-
-       //fprintf(stderr, "BINCL/EINCL info for %s\n", reader->getPath());
-       //for(std::vector<HeaderRange>::iterator it=ranges.begin(); it != ranges.end(); ++it) {
-       //      fprintf(stderr, "%08X %s\n", it->sum, it->begin->string);
-       //}
-
-       // see if any of these BINCL/EINCL ranges have already been seen and therefore can be replaced with EXCL
-       for(std::vector<HeaderRange>::iterator it=ranges.begin(); it != ranges.end(); ++it) {
-               if ( ! it->cannotEXCL ) {
-                       const char* header = it->begin->string;
-                       uint32_t sum = it->sum;
-                       PathToSums::iterator pos = sKnownBINCLs.find(header);
-                       if ( pos != sKnownBINCLs.end() ) {
-                               std::vector<uint32_t>& sums = pos->second;
-                               for(std::vector<uint32_t>::iterator sit=sums.begin(); sit != sums.end(); ++sit) {
-                                       if (*sit == sum) {
-                                               //fprintf(stderr, "use EXCL for %s in %s\n", header, reader->getPath());
-                                               it->useEXCL = true;
-                                               break;
-                                       }
-                               }
-                               if ( ! it->useEXCL ) {
-                                       // have seen this path, but not this checksum
-                                       //fprintf(stderr, "registering another checksum %08X for %s\n", sum, header);
-                                       sums.push_back(sum);
-                               }
-                       }
-                       else {
-                               // have not seen this path, so add to known BINCLs
-                               std::vector<uint32_t> empty;
-                               sKnownBINCLs[header] = empty;
-                               sKnownBINCLs[header].push_back(sum);
-                               //fprintf(stderr, "registering checksum %08X for %s\n", sum, header);
-                       }
-               }
-       }
-
-       // add a new set of stabs with BINCL/EINCL runs that have been seen before, replaced with EXCLs
-       curRangeIndex = -1;
-       const int maxRangeIndex = ranges.size();
-       int soIndex = 0;
-       for(std::vector<ObjectFile::Reader::Stab>::iterator it=readerStabs->begin(); it != readerStabs->end(); ++it) {
-               switch ( it->type ) {
-                       case N_BINCL:
-                               for(int i=curRangeIndex+1; i < maxRangeIndex; ++i) {
-                                       if ( ranges[i].begin == it ) {
-                                               curRangeIndex = i;
-                                               HeaderRange& range = ranges[curRangeIndex];
-                                               ObjectFile::Reader::Stab stab = *it;
-                                               stab.value = range.sum; // BINCL and EXCL have n_value set to checksum
-                                               if ( range.useEXCL )
-                                                       stab.type = N_EXCL;     // transform BINCL into EXCL
-                                               if ( !minimal )
-                                                       fStabs.push_back(stab);
-                                               break;
-                                       }
-                               }
-                               break;
-                       case N_EINCL:
-                               if ( curRangeIndex != -1 ) {
-                                       if ( !ranges[curRangeIndex].useEXCL && !minimal )
-                                               fStabs.push_back(*it);
-                                       curRangeIndex = ranges[curRangeIndex].parentRangeIndex;
-                               }
-                               break;
-                       default:
-                               if ( (curRangeIndex == -1) || !ranges[curRangeIndex].useEXCL ) {
-                                       ObjectFile::Reader::Stab stab = *it;
-                                       if ( !minimal || minimizeStab(stab) ) {
-                                               if ( stab.type == N_SO ) {
-                                                       if ( (stab.string != NULL) && (strlen(stab.string) > 0) ) {
-                                                               // starting SO is associated with first atom
-                                                               stab.atom = soRanges[soIndex].first;
-                                                       }
-                                                       else {
-                                                               // ending SO is associated with last atom
-                                                               stab.atom = soRanges[soIndex].second;
-                                                               ++soIndex;
-                                                       }
-                                               }
-                                               fStabs.push_back(stab);
-                                       }
-                               }
-               }
-       }
-
-}
-
-
-// used to prune out atoms that don't need debug notes generated
-class NoDebugNoteAtom
-{
-public:
-       NoDebugNoteAtom(const std::map<class ObjectFile::Reader*, uint32_t>& readersWithDwarfOrdinals)
-                       : fReadersWithDwarfOrdinals(readersWithDwarfOrdinals) {}
-
-       bool operator()(const ObjectFile::Atom* atom) const {
-               if ( atom->getSymbolTableInclusion() == ObjectFile::Atom::kSymbolTableNotIn )
-                       return true;
-               if ( atom->getName() == NULL )
-                       return true;
-               if ( fReadersWithDwarfOrdinals.find(atom->getFile()) == fReadersWithDwarfOrdinals.end() )
-                       return true;
-               return false;
-       }
-
-private:
-       const std::map<class ObjectFile::Reader*, uint32_t>& fReadersWithDwarfOrdinals;
-};
-
-// used to sort atoms with debug notes
-class ReadersWithDwarfSorter
-{
-public:
-       ReadersWithDwarfSorter(const std::map<class ObjectFile::Reader*, uint32_t>& readersWithDwarfOrdinals,
-                                                  const std::map<const class ObjectFile::Atom*, uint32_t>& atomOrdinals)
-                       : fReadersWithDwarfOrdinals(readersWithDwarfOrdinals), fAtomOrdinals(atomOrdinals) {}
-
-       bool operator()(const ObjectFile::Atom* left, const ObjectFile::Atom* right) const
-       {
-               // first sort by reader
-               unsigned int leftReaderIndex  = fReadersWithDwarfOrdinals.find(left->getFile())->second;
-               unsigned int rightReaderIndex = fReadersWithDwarfOrdinals.find(right->getFile())->second;
-               if ( leftReaderIndex != rightReaderIndex )
-                       return (leftReaderIndex < rightReaderIndex);
-
-               // then sort by atom ordinal
-               unsigned int leftAtomIndex  = fAtomOrdinals.find(left)->second;
-               unsigned int rightAtomIndex = fAtomOrdinals.find(right)->second;
-               return leftAtomIndex < rightAtomIndex;
-       }
-
-private:
-       const std::map<class ObjectFile::Reader*, uint32_t>& fReadersWithDwarfOrdinals;
-       const std::map<const class ObjectFile::Atom*, uint32_t>& fAtomOrdinals;
-};
-
-
-
-
-
-void Linker::synthesizeDebugNotes(std::vector<class ObjectFile::Atom*>& allAtomsByReader)
-{
-       // synthesize "debug notes" and add them to master stabs vector
-       const char* dirPath = NULL;
-       const char* filename = NULL;
-       bool wroteStartSO = false;
-       bool useZeroOSOModTime = (getenv("RC_RELEASE") != NULL);
-       __gnu_cxx::hash_set<const char*, __gnu_cxx::hash<const char*>, CStringEquals>  seenFiles;
-       for (std::vector<ObjectFile::Atom*>::iterator it=allAtomsByReader.begin(); it != allAtomsByReader.end(); it++) {
-               ObjectFile::Atom* atom = *it;
-               const char* newDirPath;
-               const char* newFilename;
-               //fprintf(stderr, "debug note for %s\n", atom->getDisplayName());
-               if ( atom->getTranslationUnitSource(&newDirPath, &newFilename) ) {
-                       // need SO's whenever the translation unit source file changes
-                       if ( newFilename != filename ) {
-                               // gdb like directory SO's to end in '/', but dwarf DW_AT_comp_dir usually does not have trailing '/'
-                               if ( (newDirPath != NULL) && (strlen(newDirPath) > 1 ) && (newDirPath[strlen(newDirPath)-1] != '/') )
-                                       asprintf((char**)&newDirPath, "%s/", newDirPath);
-                               if ( filename != NULL ) {
-                                       // translation unit change, emit ending SO
-                                       ObjectFile::Reader::Stab endFileStab;
-                                       endFileStab.atom                = NULL;
-                                       endFileStab.type                = N_SO;
-                                       endFileStab.other               = 1;
-                                       endFileStab.desc                = 0;
-                                       endFileStab.value               = 0;
-                                       endFileStab.string              = "";
-                                       fStabs.push_back(endFileStab);
-                               }
-                               // new translation unit, emit start SO's
-                               ObjectFile::Reader::Stab dirPathStab;
-                               dirPathStab.atom                = NULL;
-                               dirPathStab.type                = N_SO;
-                               dirPathStab.other               = 0;
-                               dirPathStab.desc                = 0;
-                               dirPathStab.value               = 0;
-                               dirPathStab.string              = newDirPath;
-                               fStabs.push_back(dirPathStab);
-                               ObjectFile::Reader::Stab fileStab;
-                               fileStab.atom           = NULL;
-                               fileStab.type           = N_SO;
-                               fileStab.other          = 0;
-                               fileStab.desc           = 0;
-                               fileStab.value          = 0;
-                               fileStab.string         = newFilename;
-                               fStabs.push_back(fileStab);
-                               // Synthesize OSO for start of file
-                               ObjectFile::Reader::Stab objStab;
-                               objStab.atom            = NULL;
-                               objStab.type            = N_OSO;
-                               // <rdar://problem/6337329> linker should put cpusubtype in n_sect field of nlist entry for N_OSO debug note entries
-                               objStab.other           = atom->getFile()->updateCpuConstraint(0); 
-                               objStab.desc            = 1;
-                               objStab.value           = useZeroOSOModTime ? 0 : atom->getFile()->getModificationTime();
-                               objStab.string          = assureFullPath(atom->getFile()->getPath());
-                               fStabs.push_back(objStab);
-                               wroteStartSO = true;
-                               // add the source file path to seenFiles so it does not show up in SOLs
-                               seenFiles.insert(newFilename);
-                       }
-                       filename = newFilename;
-                       dirPath = newDirPath;
-                       if ( atom->getSegment().isContentExecutable() && (strncmp(atom->getSectionName(), "__text", 6) == 0) ) {
-                               // Synthesize BNSYM and start FUN stabs
-                               ObjectFile::Reader::Stab beginSym;
-                               beginSym.atom           = atom;
-                               beginSym.type           = N_BNSYM;
-                               beginSym.other          = 1;
-                               beginSym.desc           = 0;
-                               beginSym.value          = 0;
-                               beginSym.string         = "";
-                               fStabs.push_back(beginSym);
-                               ObjectFile::Reader::Stab startFun;
-                               startFun.atom           = atom;
-                               startFun.type           = N_FUN;
-                               startFun.other          = 1;
-                               startFun.desc           = 0;
-                               startFun.value          = 0;
-                               startFun.string         = atom->getName();
-                               fStabs.push_back(startFun);
-                               // Synthesize any SOL stabs needed
-                               std::vector<ObjectFile::LineInfo>* lineInfo = atom->getLineInfo();
-                               if ( lineInfo != NULL ) {
-                                       const char* curFile = NULL;
-                                       for (std::vector<ObjectFile::LineInfo>::iterator it = lineInfo->begin(); it != lineInfo->end(); ++it) {
-                                               if ( it->fileName != curFile ) {
-                                                       if ( seenFiles.count(it->fileName) == 0 ) {
-                                                               seenFiles.insert(it->fileName);
-                                                               ObjectFile::Reader::Stab sol;
-                                                               sol.atom                = 0;
-                                                               sol.type                = N_SOL;
-                                                               sol.other               = 0;
-                                                               sol.desc                = 0;
-                                                               sol.value               = 0;
-                                                               sol.string              = it->fileName;
-                                                               fStabs.push_back(sol);
-                                                       }
-                                                       curFile = it->fileName;
-                                               }
-                                       }
-                               }
-                               // Synthesize end FUN and ENSYM stabs
-                               ObjectFile::Reader::Stab endFun;
-                               endFun.atom                     = atom;
-                               endFun.type                     = N_FUN;
-                               endFun.other            = 0;
-                               endFun.desc                     = 0;
-                               endFun.value            = 0;
-                               endFun.string           = "";
-                               fStabs.push_back(endFun);
-                               ObjectFile::Reader::Stab endSym;
-                               endSym.atom                     = atom;
-                               endSym.type                     = N_ENSYM;
-                               endSym.other            = 1;
-                               endSym.desc                     = 0;
-                               endSym.value            = 0;
-                               endSym.string           = "";
-                               fStabs.push_back(endSym);
-                       }
-                       else if ( atom->getSymbolTableInclusion() == ObjectFile::Atom::kSymbolTableNotIn ) {
-                               // no stabs for atoms that would not be in the symbol table
-                       }
-                       else if ( atom->getSymbolTableInclusion() == ObjectFile::Atom::kSymbolTableInAsAbsolute ) {
-                               // no stabs for absolute symbols
-                       }
-                       else if ( (strcmp(atom->getSectionName(), "__eh_frame") == 0) ) {
-                               // no stabs for .eh atoms
-                       }
-                       else if ( (strncmp(atom->getName(), "__dtrace_probe$", 15) == 0) ) {
-                               // no stabs for old style dtrace probes
-                       }
-                       else {
-                               ObjectFile::Reader::Stab globalsStab;
-                               const char* name = atom->getName();
-                               if ( atom->getScope() == ObjectFile::Atom::scopeTranslationUnit ) {
-                                       // Synthesize STSYM stab for statics
-                                       globalsStab.atom                = atom;
-                                       globalsStab.type                = N_STSYM;
-                                       globalsStab.other               = 1;
-                                       globalsStab.desc                = 0;
-                                       globalsStab.value               = 0;
-                                       globalsStab.string              = name;
-                                       fStabs.push_back(globalsStab);
-                               }
-                               else {
-                                       // Synthesize GSYM stab for other globals
-                                       globalsStab.atom                = atom;
-                                       globalsStab.type                = N_GSYM;
-                                       globalsStab.other               = 1;
-                                       globalsStab.desc                = 0;
-                                       globalsStab.value               = 0;
-                                       globalsStab.string              = name;
-                                       fStabs.push_back(globalsStab);
-                               }
-                       }
-               }
-       }
-
-       if ( wroteStartSO ) {
-               //  emit ending SO
-               ObjectFile::Reader::Stab endFileStab;
-               endFileStab.atom                = NULL;
-               endFileStab.type                = N_SO;
-               endFileStab.other               = 1;
-               endFileStab.desc                = 0;
-               endFileStab.value               = 0;
-               endFileStab.string              = "";
-               fStabs.push_back(endFileStab);
-       }
-}
-
-
-
-
-void Linker::collectDebugInfo()
-{
-       std::map<const class ObjectFile::Atom*, uint32_t>       atomOrdinals;
-       fStartDebugTime = mach_absolute_time();
-       if ( fOptions.readerOptions().fDebugInfoStripping != ObjectFile::ReaderOptions::kDebugInfoNone ) {
-
-               // determine mixture of stabs and dwarf
-               bool someStabs = false;
-               bool someDwarf = false;
-               for (std::vector<class ObjectFile::Reader*>::iterator it=fReadersThatHaveSuppliedAtoms.begin();
-                               it != fReadersThatHaveSuppliedAtoms.end();
-                               it++) {
-                       ObjectFile::Reader* reader = *it;
-                       if ( reader != NULL ) {
-                               switch ( reader->getDebugInfoKind() ) {
-                                       case ObjectFile::Reader::kDebugInfoNone:
-                                               break;
-                                       case ObjectFile::Reader::kDebugInfoStabs:
-                                               someStabs = true;
-                                               break;
-                                       case ObjectFile::Reader::kDebugInfoDwarf:
-                                               someDwarf = true;
-                                               fCreateUUID = true;
-                                               break;
-                                   case ObjectFile::Reader::kDebugInfoStabsUUID:
-                                               someStabs = true;
-                                               fCreateUUID = true;
-                                               break;
-                                       default:
-                                               throw "Unhandled type of debug information";
-                               }
-                       }
-               }
-
-               if ( someDwarf || someStabs ) {
-                       // try to minimize re-allocations
-                       fStabs.reserve(1024);
-
-                       // make mapping from atoms to ordinal
-                       uint32_t ordinal = 1;
-                       for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
-                               atomOrdinals[*it] = ordinal++;
-                       }
-               }
-
-               // process all dwarf .o files as a batch
-               if ( someDwarf ) {
-                       // make mapping from readers with dwarf to ordinal
-                       std::map<class ObjectFile::Reader*, uint32_t>   readersWithDwarfOrdinals;
-                       uint32_t readerOrdinal = 1;
-                       for (std::vector<class ObjectFile::Reader*>::iterator it=fReadersThatHaveSuppliedAtoms.begin();
-                                       it != fReadersThatHaveSuppliedAtoms.end();
-                                       it++) {
-                               ObjectFile::Reader* reader = *it;
-                               if ( (reader != NULL) && (reader->getDebugInfoKind() == ObjectFile::Reader::kDebugInfoDwarf) ) {
-                                       readersWithDwarfOrdinals[reader] = readerOrdinal++;
-                               }
-                       }
-
-                       // make a vector of atoms
-                       std::vector<class ObjectFile::Atom*> allAtomsByReader(fAllAtoms.begin(), fAllAtoms.end());
-                       // remove those not from a reader that has dwarf
-                       allAtomsByReader.erase(std::remove_if(allAtomsByReader.begin(), allAtomsByReader.end(),
-                                                               NoDebugNoteAtom(readersWithDwarfOrdinals)), allAtomsByReader.end());
-                       // sort by reader then atom ordinal
-                       std::sort(allAtomsByReader.begin(), allAtomsByReader.end(), ReadersWithDwarfSorter(readersWithDwarfOrdinals, atomOrdinals));
-                       // add debug notes for each atom
-                       this->synthesizeDebugNotes(allAtomsByReader);
-               }
-
-               // process all stabs .o files one by one
-               if ( someStabs ) {
-                       // get stabs from each reader, in command line order
-                       for (std::vector<class ObjectFile::Reader*>::iterator it=fReadersThatHaveSuppliedAtoms.begin();
-                                       it != fReadersThatHaveSuppliedAtoms.end();
-                                       it++) {
-                               ObjectFile::Reader* reader = *it;
-                               if ( reader != NULL ) {
-                                       switch ( reader->getDebugInfoKind() ) {
-                                               case ObjectFile::Reader::kDebugInfoDwarf:
-                                               case ObjectFile::Reader::kDebugInfoNone:
-                                                       // do nothing
-                                                       break;
-                                               case ObjectFile::Reader::kDebugInfoStabs:
-                                               case ObjectFile::Reader::kDebugInfoStabsUUID:
-                                                       collectStabs(reader, atomOrdinals);
-                                                       break;
-                                               default:
-                                                       throw "Unhandled type of debug information";
-                                       }
-                               }
-                       }
-                       // remove stabs associated with atoms that won't be in output
-                       std::set<class ObjectFile::Atom*>       allAtomsSet;
-                       allAtomsSet.insert(fAllAtoms.begin(), fAllAtoms.end());
-                       fStabs.erase(std::remove_if(fStabs.begin(), fStabs.end(), NotInSet(allAtomsSet)), fStabs.end());
-               }
-       }
-}
-
-void Linker::writeOutput()
-{
-       if ( fOptions.forceCpuSubtypeAll() )
-               fCurrentCpuConstraint = ObjectFile::Reader::kCpuAny;
-
-       fStartWriteTime = mach_absolute_time();
-       // tell writer about each segment's atoms
-       fOutputFileSize = fOutputFile->write(fAllAtoms, fStabs, this->entryPoint(true), 
-                                                                                       this->dyldClassicHelper(),this->dyldCompressedHelper(), this->dyldLazyLibraryHelper(),
-                                                                                       fCreateUUID, fCanScatter, 
-                                                                                       fCurrentCpuConstraint, fBiggerThanTwoGigOutput,
-                                                                                       fRegularDefAtomsThatOverrideADylibsWeakDef,  
-                                                                                       fGlobalSymbolTable.hasExternalWeakDefinitions());
-}
-
-ObjectFile::Reader* Linker::createReader(const Options::FileInfo& info)
-{
-       // map in whole file
-       uint64_t len = info.fileLen;
-       int fd = ::open(info.path, O_RDONLY, 0);
-       if ( fd == -1 )
-               throwf("can't open file, errno=%d", errno);
-       if ( info.fileLen < 20 )
-               throw "file too small";
-
-       uint8_t* p = (uint8_t*)::mmap(NULL, info.fileLen, PROT_READ, MAP_FILE | MAP_PRIVATE, fd, 0);
-       if ( p == (uint8_t*)(-1) )
-               throwf("can't map file, errno=%d", errno);
-
-       // if fat file, skip to architecture we want
-       // Note: fat header is always big-endian
-       const fat_header* fh = (fat_header*)p;
-       if ( fh->magic == OSSwapBigToHostInt32(FAT_MAGIC) ) {
-               const struct fat_arch* archs = (struct fat_arch*)(p + sizeof(struct fat_header));
-               uint32_t sliceToUse;
-               bool sliceFound = false;
-               if ( fOptions.preferSubArchitecture() ) {
-                       // first try to find a slice that match cpu-type and cpu-sub-type
-                       for (uint32_t i=0; i < OSSwapBigToHostInt32(fh->nfat_arch); ++i) {
-                               if ( (OSSwapBigToHostInt32(archs[i].cputype) == (uint32_t)fArchitecture)
-                                 && (OSSwapBigToHostInt32(archs[i].cpusubtype) == (uint32_t)fOptions.subArchitecture()) ) {
-                                       sliceToUse = i;
-                                       sliceFound = true;
-                                       break;
-                               }
-                       }
-               }
-               if ( !sliceFound ) {
-                       // look for any slice that matches just cpu-type
-                       for (uint32_t i=0; i < OSSwapBigToHostInt32(fh->nfat_arch); ++i) {
-                               if ( OSSwapBigToHostInt32(archs[i].cputype) == (uint32_t)fArchitecture ) {
-                                       sliceToUse = i;
-                                       sliceFound = true;
-                                       break;
-                               }
-                       }
-               }
-               if ( sliceFound ) {
-                       uint32_t fileOffset = OSSwapBigToHostInt32(archs[sliceToUse].offset);
-                       len = OSSwapBigToHostInt32(archs[sliceToUse].size);
-                       // if requested architecture is page aligned within fat file, then remap just that portion of file
-                       if ( (fileOffset & 0x00000FFF) == 0 ) {
-                               // unmap whole file
-                               munmap((caddr_t)p, info.fileLen);
-                               // re-map just part we need
-                               p = (uint8_t*)::mmap(NULL, len, PROT_READ, MAP_FILE | MAP_PRIVATE, fd, fileOffset);
-                               if ( p == (uint8_t*)(-1) )
-                                       throwf("can't re-map file, errno=%d", errno);
-                       }
-                       else {
-                               p = &p[fileOffset];
-                       }
-               }
-       }
-       ::close(fd);
-
-       bool objSubtypeMustMatch = (fOptions.preferSubArchitecture() && !fOptions.allowSubArchitectureMismatches());
-       switch (fArchitecture) {
-               case CPU_TYPE_POWERPC:
-                       if ( mach_o::relocatable::Reader<ppc>::validFile(p) )
-                               return this->addObject(new mach_o::relocatable::Reader<ppc>::Reader(p, info.path, info.modTime, fOptions.readerOptions(), fNextInputOrdinal), info, len);
-                       else if ( mach_o::dylib::Reader<ppc>::validFile(p, info.options.fBundleLoader) )
-                               return this->addDylib(new mach_o::dylib::Reader<ppc>::Reader(p, len, info.path, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
-                       else if ( archive::Reader<ppc>::validFile(p, len) )
-                               return this->addArchive(new archive::Reader<ppc>::Reader(p, len, info.path, info.modTime, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
-                       break;
-               case CPU_TYPE_POWERPC64:
-                       if ( mach_o::relocatable::Reader<ppc64>::validFile(p) )
-                               return this->addObject(new mach_o::relocatable::Reader<ppc64>::Reader(p, info.path, info.modTime, fOptions.readerOptions(), fNextInputOrdinal), info, len);
-                       else if ( mach_o::dylib::Reader<ppc64>::validFile(p, info.options.fBundleLoader) )
-                               return this->addDylib(new mach_o::dylib::Reader<ppc64>::Reader(p, len, info.path, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
-                       else if ( archive::Reader<ppc64>::validFile(p, len) )
-                               return this->addArchive(new archive::Reader<ppc64>::Reader(p, len, info.path, info.modTime, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
-                       break;
-               case CPU_TYPE_I386:
-                       if ( mach_o::relocatable::Reader<x86>::validFile(p) )
-                               return this->addObject(new mach_o::relocatable::Reader<x86>::Reader(p, info.path, info.modTime, fOptions.readerOptions(), fNextInputOrdinal), info, len);
-                       else if ( mach_o::dylib::Reader<x86>::validFile(p, info.options.fBundleLoader) )
-                               return this->addDylib(new mach_o::dylib::Reader<x86>::Reader(p, len, info.path, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
-                       else if ( archive::Reader<x86>::validFile(p, len) )
-                               return this->addArchive(new archive::Reader<x86>::Reader(p, len, info.path, info.modTime, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
-                       break;
-               case CPU_TYPE_X86_64:
-                       if ( mach_o::relocatable::Reader<x86_64>::validFile(p) )
-                               return this->addObject(new mach_o::relocatable::Reader<x86_64>::Reader(p, info.path, info.modTime, fOptions.readerOptions(), fNextInputOrdinal), info, len);
-                       else if ( mach_o::dylib::Reader<x86_64>::validFile(p, info.options.fBundleLoader) )
-                               return this->addDylib(new mach_o::dylib::Reader<x86_64>::Reader(p, len, info.path, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
-                       else if ( archive::Reader<x86_64>::validFile(p, len) )
-                               return this->addArchive(new archive::Reader<x86_64>::Reader(p, len, info.path, info.modTime, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
-               case CPU_TYPE_ARM:
-                       if ( mach_o::relocatable::Reader<arm>::validFile(p, objSubtypeMustMatch, fOptions.subArchitecture()) )
-                                       return this->addObject(new mach_o::relocatable::Reader<arm>::Reader(p, info.path, info.modTime, fOptions.readerOptions(), fNextInputOrdinal), info, len);
-                       else if ( mach_o::dylib::Reader<arm>::validFile(p, info.options.fBundleLoader) )
-                               return this->addDylib(new mach_o::dylib::Reader<arm>::Reader(p, len, info.path, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
-                       else if ( archive::Reader<arm>::validFile(p, len) )
-                               return this->addArchive(new archive::Reader<arm>::Reader(p, len, info.path, info.modTime, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
-                       break;
-       }
-
-#if LTO_SUPPORT
-       if ( lto::Reader::validFile(p, len, fArchitecture) ) {
-               return this->addObject(new lto::Reader(p, len, info.path, info.modTime, fOptions.readerOptions(), fArchitecture), info, len);
-       }
-       else if ( !lto::Reader::loaded() && (p[0] == 'B') && (p[1] == 'C')  ) {
-               throw "could not process object file.  Looks like an llvm bitcode object file, but libLTO.dylib could not be loaded";
-       }
-#endif
-       // error handling
-       if ( ((fat_header*)p)->magic == OSSwapBigToHostInt32(FAT_MAGIC) ) {
-               throwf("missing required architecture %s in file", fArchitectureName);
-       }
-       else {
-               throw "file is not of required architecture";
-       }
-}
-
-void Linker::logDylib(ObjectFile::Reader* reader, bool indirect)
-{
-       if ( fOptions.readerOptions().fTraceDylibs ) {
-               const char* fullPath = reader->getPath();
-               char realName[MAXPATHLEN];
-               if ( realpath(fullPath, realName) != NULL )
-                       fullPath = realName;
-               if ( indirect )
-                       logTraceInfo("[Logging for XBS] Used indirect dynamic library: %s\n", fullPath);
-               else
-                       logTraceInfo("[Logging for XBS] Used dynamic library: %s\n", fullPath);
-       }
-}
-
-
-
-ObjectFile::Reader* Linker::findDylib(const char* installPath, const char* fromPath)
-{
-       //fprintf(stderr, "findDylib(%s, %s)\n", installPath, fromPath);
-       InstallNameToReader::iterator pos = fDylibMap.find(installPath);
-       if ( pos != fDylibMap.end() ) {
-               return pos->second;
-       }
-       else {
-               // allow -dylib_path option to override indirect library to use
-               for (std::vector<Options::DylibOverride>::iterator dit = fOptions.dylibOverrides().begin(); dit != fOptions.dylibOverrides().end(); ++dit) {
-                       if ( strcmp(dit->installName,installPath) == 0 ) {\
-                               try {
-                                       Options::FileInfo info = fOptions.findFile(dit->useInstead);
-                                       ObjectFile::Reader* reader = this->createReader(info);
-                                       fDylibMap[strdup(installPath)] = reader;
-                                       this->logDylib(reader, true);
-                                       return reader;
-                               }
-                               catch (const char* msg) {
-                                       warning("ignoring -dylib_file option, %s", msg);
-                               }
-                       }
-               }
-               char newPath[MAXPATHLEN];
-               // handle @loader_path
-               if ( strncmp(installPath, "@loader_path/", 13) == 0 ) {
-                       strcpy(newPath, fromPath);
-                       char* addPoint = strrchr(newPath,'/');
-                       if ( addPoint != NULL )
-                               strcpy(&addPoint[1], &installPath[13]);
-                       else
-                               strcpy(newPath, &installPath[13]);
-                       installPath = newPath;
-               }
-               // note: @executable_path case is handled inside findFileUsingPaths()
-               // search for dylib using -F and -L paths
-               Options::FileInfo info = fOptions.findFileUsingPaths(installPath);
-               try {
-                       ObjectFile::Reader* reader = this->createReader(info);
-                       fDylibMap[strdup(installPath)] = reader;
-                       this->logDylib(reader, true);
-                       return reader;
-               }
-               catch (const char* msg) {
-                       throwf("in %s, %s", info.path, msg);
-               }
-       }
-}
-
-
-void Linker::processDylibs()
-{
-       fAllDirectDylibsLoaded = true;
-
-       // mark all dylibs initially specified as required and check if they can be used
-       for (InstallNameToReader::iterator it=fDylibMap.begin(); it != fDylibMap.end(); it++) {
-               it->second->setExplicitlyLinked();
-               this->checkDylibClientRestrictions(it->second);
-       }
-       
-       // keep processing dylibs until no more dylibs are added
-       unsigned long lastMapSize = 0;
-       while ( lastMapSize != fDylibMap.size() ) {
-               lastMapSize = fDylibMap.size();
-               // can't iterator fDylibMap while modifying it, so use temp buffer
-               std::vector<ObjectFile::Reader*> currentUnprocessedReaders;
-               for (InstallNameToReader::iterator it=fDylibMap.begin(); it != fDylibMap.end(); it++) {
-                       if ( fDylibsProcessed.count(it->second) == 0 )
-                               currentUnprocessedReaders.push_back(it->second);
-               }
-               for (std::vector<ObjectFile::Reader*>::iterator it=currentUnprocessedReaders.begin(); it != currentUnprocessedReaders.end(); it++) {
-                       fDylibsProcessed.insert(*it);
-                       (*it)->processIndirectLibraries(this);
-               }
-       }
-       
-       // go back over original dylibs and mark sub frameworks as re-exported
-       if ( fOptions.outputKind() == Options::kDynamicLibrary ) {
-               const char* myLeaf = strrchr(fOptions.installPath(), '/');
-               if ( myLeaf != NULL ) {
-                       for (std::vector<class ObjectFile::Reader*>::iterator it=fInputFiles.begin(); it != fInputFiles.end(); it++) {
-                               ObjectFile::Reader* reader = *it;
-                               const char* childParent = reader->parentUmbrella();
-                               if ( childParent != NULL ) {
-                                       if ( strcmp(childParent, &myLeaf[1]) == 0 ) {
-                                               // set re-export bit of info
-                                               std::map<ObjectFile::Reader*,LibraryOptions>::iterator pos = fDylibOptionsMap.find(reader);
-                                               if ( pos != fDylibOptionsMap.end() ) {
-                                                       pos->second.fReExport = true;
-                                               }
-                                       }
-                               }
-                       }
-               }
-       }
-       
-}
-
-       
-
-void Linker::createReaders()
-{
-       fStartCreateReadersTime = mach_absolute_time();
-       std::vector<Options::FileInfo>& files = fOptions.getInputFiles();
-       const int count = files.size();
-       if ( count == 0 )
-               throw "no object files specified";
-       // add all direct object, archives, and dylibs
-       for (int i=0; i < count; ++i) {
-               Options::FileInfo& entry = files[i];
-               // ignore /usr/lib/dyld on command line in crt.o build
-               if ( strcmp(entry.path, "/usr/lib/dyld") != 0 ) {
-                       try {
-                               this->addInputFile(this->createReader(entry), entry);
-                       }
-                       catch (const char* msg) {
-                               if ( (strstr(msg, "architecture") != NULL) && !fOptions.errorOnOtherArchFiles() ) {
-                                       if ( fOptions.ignoreOtherArchInputFiles() ) {
-                                               // ignore, because this is about an architecture not in use
-                                       }
-                                       else {
-                                               warning("in %s, %s", entry.path, msg);
-                                       }
-                               }
-                               else {
-                                       throwf("in %s, %s", entry.path, msg);
-                               }
-                       }
-               }
-       }
-
-       this->processDylibs();
-}
-
-
-
-ObjectFile::Reader* Linker::addArchive(ObjectFile::Reader* reader, const Options::FileInfo& info, uint64_t mappedLen)
-{
-       fNextInputOrdinal += mappedLen;
-       // remember which readers are archives because they are logged differently
-       fArchiveReaders.insert(reader);
-
-       // update stats
-       fTotalArchiveSize += mappedLen;
-       ++fTotalArchivesLoaded;
-       return reader;
-}
-
-ObjectFile::Reader* Linker::addObject(ObjectFile::Reader* reader, const Options::FileInfo& info, uint64_t mappedLen)
-{
-       fNextInputOrdinal += mappedLen;
-       // any .o files that don't have MH_SUBSECTIONS_VIA_SYMBOLS, that means a generated .o file can't
-       if ( (fOptions.outputKind() == Options::kObjectFile) && !reader->canScatterAtoms() )
-               fCanScatter = false;
-
-       // update stats
-       fTotalObjectSize += mappedLen;
-       ++fTotalObjectLoaded;
-       return reader;
-}
-
-
-void Linker::checkDylibClientRestrictions(ObjectFile::Reader* reader)
-{
-       // Check for any restrictions on who can link with this dylib  
-       const char* readerParentName = reader->parentUmbrella() ;
-       std::vector<const char*>* clients = reader->getAllowableClients();
-       if ( (readerParentName != NULL) || (clients != NULL) ) {
-               // only dylibs that are in an umbrella or have a client list need verification
-               const char* installName = fOptions.installPath();
-               const char* installNameLastSlash = strrchr(installName, '/');
-               bool isParent = false;
-               bool isSibling = false;
-               bool isAllowableClient = false;
-               // There are three cases:
-               if ( (readerParentName != NULL) && (installNameLastSlash != NULL) ) {
-                       // case 1) The dylib has a parent umbrella, and we are creating the parent umbrella
-                       isParent = ( strcmp(&installNameLastSlash[1], readerParentName) == 0 );
-                       
-                       // hack to support umbrella variants that encode the variant name in the install name 
-                       // e.g. CoreServices_profile
-                       if ( !isParent ) {
-                               const char* underscore = strchr(&installNameLastSlash[1], '_');
-                               if ( underscore != NULL ) {
-                                       isParent = ( strncmp(&installNameLastSlash[1], readerParentName, underscore-installNameLastSlash-1) == 0 );
-                               }
-                       }
-                       
-                       // case 2) The dylib has a parent umbrella, and we are creating a sibling with the same parent
-                       isSibling = ( (fOptions.umbrellaName() != NULL) && (strcmp(fOptions.umbrellaName(), readerParentName) == 0) );
-               }
-
-               if ( !isParent && !isSibling && (clients != NULL) ) {
-                       // case 3) the dylib has a list of allowable clients, and we are creating one of them
-                       const char* clientName = fOptions.clientName();
-                       int clientNameLen = 0;
-                       if ( clientName != NULL ) {
-                               // use client name as specified on command line
-                               clientNameLen = strlen(clientName);
-                       }
-                       else {
-                               // infer client name from output path (e.g. xxx/libfoo_variant.A.dylib --> foo, Bar.framework/Bar_variant --> Bar)
-                               clientName = installName;
-                               clientNameLen = strlen(clientName);
-                               // starts after last slash
-                               if ( installNameLastSlash != NULL )
-                                       clientName = &installNameLastSlash[1];
-                               if ( strncmp(clientName, "lib", 3) == 0 )
-                                       clientName = &clientName[3];
-                               // up to first dot
-                               const char* firstDot = strchr(clientName, '.');
-                               if ( firstDot != NULL )
-                                       clientNameLen = firstDot - clientName;
-                               // up to first underscore
-                               const char* firstUnderscore = strchr(clientName, '_');
-                               if ( (firstUnderscore != NULL) && ((firstUnderscore - clientName) < clientNameLen) )
-                                       clientNameLen = firstUnderscore - clientName;
-                       }
-
-                       // Use clientName to check if this dylib is able to link against the allowable clients.
-                       for (std::vector<const char*>::iterator it = clients->begin(); it != clients->end(); it++) {
-                               if ( strncmp(*it, clientName, clientNameLen) == 0 )
-                                       isAllowableClient = true;
-                       }
-               }
-       
-               if ( !isParent && !isSibling && !isAllowableClient ) {
-                       if ( readerParentName != NULL ) {
-                               throwf("cannot link directly with %s.  Link against the umbrella framework '%s.framework' instead.", 
-                                       reader->getPath(), readerParentName);
-                       }
-                       else {
-                               throwf("cannot link directly with %s", reader->getPath());
-                       }
-               }
-       }
-}
-
-
-ObjectFile::Reader* Linker::addDylib(ObjectFile::Reader* reader, const Options::FileInfo& info, uint64_t mappedLen)
-{
-       switch ( fOptions.outputKind() ) {
-               case Options::kDynamicExecutable:
-               case Options::kDynamicLibrary:
-               case Options::kDynamicBundle:
-                       break;
-               case Options::kStaticExecutable:
-               case Options::kDyld:
-               case Options::kPreload:
-               case Options::kObjectFile:
-               case Options::kKextBundle:
-                       warning("unexpected dylib (%s) on link line", reader->getPath());
-                       break;
-       }
-
-       fNextInputOrdinal += mappedLen;
-       if ( (reader->getInstallPath() == NULL) && !info.options.fBundleLoader ) {
-               // this is a "blank" stub
-               // silently ignore it
-               return reader;
-       }
-       // add to map of loaded dylibs
-       const char* installPath = reader->getInstallPath();
-       if ( installPath != NULL ) {
-               InstallNameToReader::iterator pos = fDylibMap.find(installPath);
-               if ( pos == fDylibMap.end() ) {
-                       fDylibMap[strdup(installPath)] = reader;
-               }
-               else {
-                       InstallNameToReader::iterator pos2 = fDylibMap.find(reader->getPath());
-                       if ( pos2 == fDylibMap.end() ) 
-                               fDylibMap[strdup(reader->getPath())] = reader;
-                       else
-                               warning("duplicate dylib %s", reader->getPath());
-               }
-       }
-       else if ( info.options.fBundleLoader )
-               fBundleLoaderReader = reader;
-
-       // log direct readers
-       if ( !fAllDirectDylibsLoaded ) 
-               this->logDylib(reader, false);
-
-       // update stats
-       ++fTotalDylibsLoaded;
-
-       return reader;
-}
-
-
-void Linker::logTraceInfo (const char* format, ...)
-{
-       static int trace_file = -1;
-       char trace_buffer[MAXPATHLEN * 2];
-       char *buffer_ptr;
-       int length;
-       ssize_t amount_written;
-       const char *trace_file_path = fOptions.readerOptions().fTraceOutputFile;
-
-       if(trace_file == -1) {
-               if(trace_file_path != NULL) {
-                       trace_file = open(trace_file_path, O_WRONLY | O_APPEND | O_CREAT, 0666);
-                       if(trace_file == -1)
-                               throwf("Could not open or create trace file: %s", trace_file_path);
-               }
-               else {
-                       trace_file = fileno(stderr);
-               }
-       }
-
-    va_list ap;
-       va_start(ap, format);
-       length = vsnprintf(trace_buffer, sizeof(trace_buffer), format, ap);
-       va_end(ap);
-       buffer_ptr = trace_buffer;
-
-       while(length > 0) {
-               amount_written = write(trace_file, buffer_ptr, length);
-               if(amount_written == -1)
-                       /* Failure to write shouldn't fail the build. */
-                       return;
-               buffer_ptr += amount_written;
-               length -= amount_written;
-       }
-}
-
-
-
-void Linker::createWriter()
-{
-       fStartCreateWriterTime = mach_absolute_time();
-
-       // make a vector out of all required dylibs in fDylibMap
-       std::vector<ExecutableFile::DyLibUsed>  dynamicLibraries;
-       // need to preserve command line order 
-       for (std::vector<class ObjectFile::Reader*>::iterator it=fInputFiles.begin(); it != fInputFiles.end(); it++) {
-               ObjectFile::Reader* reader = *it;
-               for (InstallNameToReader::iterator mit=fDylibMap.begin(); mit != fDylibMap.end(); mit++) {
-                       if ( reader == mit->second ) {
-                               ExecutableFile::DyLibUsed dylibInfo;
-                               dylibInfo.reader = reader;
-                               dylibInfo.options = fDylibOptionsMap[reader];
-                               dynamicLibraries.push_back(dylibInfo);
-                               break;
-                       }
-               }
-       }
-       // then add any other dylibs
-       for (InstallNameToReader::iterator it=fDylibMap.begin(); it != fDylibMap.end(); it++) {
-               if ( it->second->implicitlyLinked()  ) {
-                       // if not already in dynamicLibraries
-                       bool alreadyInDynamicLibraries = false;
-                       for (std::vector<ExecutableFile::DyLibUsed>::iterator dit=dynamicLibraries.begin(); dit != dynamicLibraries.end(); dit++) {
-                               if ( dit->reader == it->second ) {
-                                       alreadyInDynamicLibraries = true;
-                                       break;
-                               }
-                       }
-                       if ( ! alreadyInDynamicLibraries ) {    
-                               ExecutableFile::DyLibUsed dylibInfo;
-                               dylibInfo.reader = it->second;
-                               std::map<ObjectFile::Reader*,LibraryOptions>::iterator pos = fDylibOptionsMap.find(it->second);
-                               if ( pos != fDylibOptionsMap.end() ) {
-                                       dylibInfo.options = pos->second;
-                               }
-                               else {
-                                       dylibInfo.options.fWeakImport = false;          // FIX ME
-                                       dylibInfo.options.fReExport = false;
-                                       dylibInfo.options.fBundleLoader = false;
-                               }
-                               dynamicLibraries.push_back(dylibInfo);
-                       }
-               }
-       }
-       if ( fBundleLoaderReader != NULL ) {
-               ExecutableFile::DyLibUsed dylibInfo;
-               dylibInfo.reader = fBundleLoaderReader;
-               dylibInfo.options.fWeakImport = false;          
-               dylibInfo.options.fReExport = false;
-               dylibInfo.options.fBundleLoader = true;
-               dynamicLibraries.push_back(dylibInfo);
-       }
-
-       const char* path = fOptions.getOutputFilePath();
-       switch ( fArchitecture ) {
-               case CPU_TYPE_POWERPC:
-                       this->setOutputFile(new mach_o::executable::Writer<ppc>(path, fOptions, dynamicLibraries));
-                       break;
-               case CPU_TYPE_POWERPC64:
-                       this->setOutputFile(new mach_o::executable::Writer<ppc64>(path, fOptions, dynamicLibraries));
-                       break;
-               case CPU_TYPE_I386:
-                       this->setOutputFile(new mach_o::executable::Writer<x86>(path, fOptions, dynamicLibraries));
-                       break;
-               case CPU_TYPE_X86_64:
-                       this->setOutputFile(new mach_o::executable::Writer<x86_64>(path, fOptions, dynamicLibraries));
-                       break;
-               case CPU_TYPE_ARM:
-                       this->setOutputFile(new mach_o::executable::Writer<arm>(path, fOptions, dynamicLibraries));
-                       break;
-               default:
-                       throw "unknown architecture";
-       }
-}
-
-
-Linker::SymbolTable::SymbolTable(Linker& owner)
- : fOwner(owner), fRequireCount(0), fHasExternalTentativeDefinitions(false), fHasExternalWeakDefinitions(false)
-{
-}
-
-void Linker::SymbolTable::require(const char* name)
-{
-       //fprintf(stderr, "require(%s)\n", name);
-       Mapper::iterator pos = fTable.find(name);
-       if ( pos == fTable.end() ) {
-               fTable[name] = NULL;
-               ++fRequireCount;
-       }
-}
-
-// convenience labels for 2-dimensional switch statement
-enum AllDefinitionCombinations {
-       kRegAndReg                              = (ObjectFile::Atom::kRegularDefinition << 3)   | ObjectFile::Atom::kRegularDefinition,
-       kRegAndWeak                             = (ObjectFile::Atom::kRegularDefinition << 3)   | ObjectFile::Atom::kWeakDefinition,
-       kRegAndTent                             = (ObjectFile::Atom::kRegularDefinition << 3)   | ObjectFile::Atom::kTentativeDefinition,
-       kRegAndExtern                   = (ObjectFile::Atom::kRegularDefinition << 3)   | ObjectFile::Atom::kExternalDefinition,
-       kRegAndExternWeak               = (ObjectFile::Atom::kRegularDefinition << 3)   | ObjectFile::Atom::kExternalWeakDefinition,
-       kRegAndAbsolute                 = (ObjectFile::Atom::kRegularDefinition << 3)   | ObjectFile::Atom::kAbsoluteSymbol,
-       kWeakAndReg                             = (ObjectFile::Atom::kWeakDefinition << 3)              | ObjectFile::Atom::kRegularDefinition,
-       kWeakAndWeak                    = (ObjectFile::Atom::kWeakDefinition << 3)              | ObjectFile::Atom::kWeakDefinition,
-       kWeakAndTent                    = (ObjectFile::Atom::kWeakDefinition << 3)              | ObjectFile::Atom::kTentativeDefinition,
-       kWeakAndExtern                  = (ObjectFile::Atom::kWeakDefinition << 3)              | ObjectFile::Atom::kExternalDefinition,
-       kWeakAndExternWeak              = (ObjectFile::Atom::kWeakDefinition << 3)              | ObjectFile::Atom::kExternalWeakDefinition,
-       kWeakAndAbsolute                = (ObjectFile::Atom::kWeakDefinition << 3)              | ObjectFile::Atom::kAbsoluteSymbol,
-       kTentAndReg                             = (ObjectFile::Atom::kTentativeDefinition << 3) | ObjectFile::Atom::kRegularDefinition,
-       kTentAndWeak                    = (ObjectFile::Atom::kTentativeDefinition << 3) | ObjectFile::Atom::kWeakDefinition,
-       kTentAndTent                    = (ObjectFile::Atom::kTentativeDefinition << 3) | ObjectFile::Atom::kTentativeDefinition,
-       kTentAndExtern                  = (ObjectFile::Atom::kTentativeDefinition << 3) | ObjectFile::Atom::kExternalDefinition,
-       kTentAndExternWeak              = (ObjectFile::Atom::kTentativeDefinition << 3) | ObjectFile::Atom::kExternalWeakDefinition,
-       kTentAndAbsolute                = (ObjectFile::Atom::kTentativeDefinition << 3) | ObjectFile::Atom::kAbsoluteSymbol,
-       kExternAndReg                   = (ObjectFile::Atom::kExternalDefinition << 3)  | ObjectFile::Atom::kRegularDefinition,
-       kExternAndWeak                  = (ObjectFile::Atom::kExternalDefinition << 3)  | ObjectFile::Atom::kWeakDefinition,
-       kExternAndTent                  = (ObjectFile::Atom::kExternalDefinition << 3)  | ObjectFile::Atom::kTentativeDefinition,
-       kExternAndExtern                = (ObjectFile::Atom::kExternalDefinition << 3)  | ObjectFile::Atom::kExternalDefinition,
-       kExternAndExternWeak    = (ObjectFile::Atom::kExternalDefinition << 3)  | ObjectFile::Atom::kExternalWeakDefinition,
-       kExternAndAbsolute              = (ObjectFile::Atom::kExternalDefinition << 3)  | ObjectFile::Atom::kAbsoluteSymbol,
-       kExternWeakAndReg               = (ObjectFile::Atom::kExternalWeakDefinition << 3) | ObjectFile::Atom::kRegularDefinition,
-       kExternWeakAndWeak              = (ObjectFile::Atom::kExternalWeakDefinition << 3) | ObjectFile::Atom::kWeakDefinition,
-       kExternWeakAndTent              = (ObjectFile::Atom::kExternalWeakDefinition << 3) | ObjectFile::Atom::kTentativeDefinition,
-       kExternWeakAndExtern    = (ObjectFile::Atom::kExternalWeakDefinition << 3) | ObjectFile::Atom::kExternalDefinition,
-       kExternWeakAndExternWeak= (ObjectFile::Atom::kExternalWeakDefinition << 3) | ObjectFile::Atom::kExternalWeakDefinition,
-       kExternWeakAndAbsolute  = (ObjectFile::Atom::kExternalWeakDefinition << 3) | ObjectFile::Atom::kAbsoluteSymbol,
-       kAbsoluteAndReg                 = (ObjectFile::Atom::kAbsoluteSymbol << 3)              | ObjectFile::Atom::kRegularDefinition,
-       kAbsoluteAndWeak                = (ObjectFile::Atom::kAbsoluteSymbol << 3)              | ObjectFile::Atom::kWeakDefinition,
-       kAbsoluteAndTent                = (ObjectFile::Atom::kAbsoluteSymbol << 3)              | ObjectFile::Atom::kTentativeDefinition,
-       kAbsoluteAndExtern              = (ObjectFile::Atom::kAbsoluteSymbol << 3)              | ObjectFile::Atom::kExternalDefinition,
-       kAbsoluteAndExternWeak  = (ObjectFile::Atom::kAbsoluteSymbol << 3)              | ObjectFile::Atom::kExternalWeakDefinition,
-       kAbsoluteAndAbsolute    = (ObjectFile::Atom::kAbsoluteSymbol << 3)              | ObjectFile::Atom::kAbsoluteSymbol
-};
-
-bool Linker::SymbolTable::add(ObjectFile::Atom& newAtom)
-{
-       bool useNew = true;
-       bool checkVisibilityMismatch = false;
-       const char* name = newAtom.getName();
-       //fprintf(stderr, "map.add(%s => %p from %s)\n", name, &newAtom, newAtom.getFile()->getPath());
-       Mapper::iterator pos = fTable.find(name);
-       ObjectFile::Atom* existingAtom = NULL;
-       if ( pos != fTable.end() )
-               existingAtom = pos->second;
-       if ( existingAtom != NULL ) {
-               // already have atom with same name in symbol table
-               switch ( (AllDefinitionCombinations)((existingAtom->getDefinitionKind() << 3) | newAtom.getDefinitionKind()) ) {
-                       case kRegAndReg:
-                               throwf("duplicate symbol %s in %s and %s", name, newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
-                       case kRegAndWeak:
-                               // ignore new weak atom, because we already have a non-weak one
-                               useNew = false;
-                               break;
-                       case kRegAndTent:
-                               // ignore new tentative atom, because we already have a regular one
-                               useNew = false;
-                               checkVisibilityMismatch = true;
-                               if ( newAtom.getSize() > existingAtom->getSize() ) {
-                                       warning("for symbol %s tentative definition of size %llu from %s is "
-                                                                       "is smaller than the real definition of size %llu from %s",
-                                                                       newAtom.getDisplayName(), newAtom.getSize(), newAtom.getFile()->getPath(),
-                                                                       existingAtom->getSize(), existingAtom->getFile()->getPath());
-                               }
-                               break;
-                       case kRegAndExtern:
-                               // ignore external atom, because we already have a one
-                               useNew = false;
-                               break;
-                       case kRegAndExternWeak:
-                               // ignore external atom, because we already have a one
-                               useNew = false;
-                               break;
-                       case kRegAndAbsolute:
-                               throwf("duplicate symbol %s in %s and %s", name, newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
-                               break;
-                       case kWeakAndReg:
-                               // replace existing weak atom with regular one
-                               break;
-                       case kWeakAndWeak:
-                               // have another weak atom, use whichever has largest alignment requirement
-                               // because codegen of some client may require alignment
-                               useNew = ( newAtom.getAlignment().trailingZeros() > existingAtom->getAlignment().trailingZeros() );
-                               checkVisibilityMismatch = true;
-                               break;
-                       case kWeakAndTent:
-                               // replace existing weak atom with tentative one ???
-                               break;
-                       case kWeakAndExtern:
-                               // keep weak atom, at runtime external one may override
-                               useNew = false;
-                               break;
-                       case kWeakAndExternWeak:
-                               // keep weak atom, at runtime external one may override
-                               useNew = false;
-                               break;
-                       case kWeakAndAbsolute:
-                               // replace existing weak atom with absolute one
-                               break;
-                       case kTentAndReg:
-                               // replace existing tentative atom with regular one
-                               checkVisibilityMismatch = true;
-                               if ( newAtom.getSize() < existingAtom->getSize() ) {
-                                       warning("for symbol %s tentative definition of size %llu from %s is "
-                                                                       "being replaced by a real definition of size %llu from %s",
-                                                                       newAtom.getDisplayName(), existingAtom->getSize(), existingAtom->getFile()->getPath(),
-                                                                       newAtom.getSize(), newAtom.getFile()->getPath());
-                               }
-                               break;
-                       case kTentAndWeak:
-                               // replace existing tentative atom with weak one ???
-                               break;
-                       case kTentAndTent:
-                               // use largest
-                               checkVisibilityMismatch = true;
-                               if ( newAtom.getSize() < existingAtom->getSize() ) {
-                                       useNew = false;
-                               } 
-                               else {
-                                       if ( newAtom.getAlignment().trailingZeros() < existingAtom->getAlignment().trailingZeros() )
-                                               warning("alignment lost in merging tentative definition %s", newAtom.getDisplayName());
-                               }
-                               break;
-                       case kTentAndExtern:
-                       case kTentAndExternWeak:
-                               // a tentative definition and a dylib definition, so commons-mode decides how to handle
-                               switch ( fOwner.fOptions.commonsMode() ) {
-                                       case Options::kCommonsIgnoreDylibs:
-                                               if ( fOwner.fOptions.warnCommons() )
-                                                       warning("using common symbol %s from %s and ignoring defintion from dylib %s",
-                                                                       existingAtom->getName(), existingAtom->getFile()->getPath(), newAtom.getFile()->getPath());
-                                               useNew = false;
-                                               break;
-                                       case Options::kCommonsOverriddenByDylibs:
-                                               if ( fOwner.fOptions.warnCommons() )
-                                                       warning("replacing common symbol %s from %s with true definition from dylib %s",
-                                                                       existingAtom->getName(), existingAtom->getFile()->getPath(), newAtom.getFile()->getPath());
-                                               break;
-                                       case Options::kCommonsConflictsDylibsError:
-                                               throwf("common symbol %s from %s conflicts with defintion from dylib %s",
-                                                               existingAtom->getName(), existingAtom->getFile()->getPath(), newAtom.getFile()->getPath());
-                               }
-                               break;
-                       case kTentAndAbsolute:
-                               // replace tentative with absolute (can't size check because absolutes have no size)
-                               break;
-                       case kExternAndReg:
-                               // replace external atom with regular one
-                               break;
-                       case kExternAndWeak:
-                               // replace external atom with weak one
-                               break;
-                       case kExternAndTent:
-                               // a tentative definition and a dylib definition, so commons-mode decides how to handle
-                               switch ( fOwner.fOptions.commonsMode() ) {
-                                       case Options::kCommonsIgnoreDylibs:
-                                               if ( fOwner.fOptions.warnCommons() )
-                                                       warning("using common symbol %s from %s and ignoring defintion from dylib %s",
-                                                                       newAtom.getName(), newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
-                                               break;
-                                       case Options::kCommonsOverriddenByDylibs:
-                                               if ( fOwner.fOptions.warnCommons() )
-                                                       warning("replacing defintion of %s from dylib %s with common symbol from %s",
-                                                                       newAtom.getName(), existingAtom->getFile()->getPath(), newAtom.getFile()->getPath());
-                                               useNew = false;
-                                               break;
-                                       case Options::kCommonsConflictsDylibsError:
-                                               throwf("common symbol %s from %s conflicts with defintion from dylib %s",
-                                                                       newAtom.getName(), newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
-                               }
-                               break;
-                       case kExternAndExtern:
-                               throwf("duplicate symbol %s in %s and %s\n", name, newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
-                       case kExternAndExternWeak:
-                               // keep strong dylib atom, ignore weak one
-                               useNew = false;
-                               break;
-                       case kExternAndAbsolute:
-                               // replace external atom with absolute one
-                               break;
-                       case kExternWeakAndReg:
-                               // replace existing weak external with regular
-                               break;
-                       case kExternWeakAndWeak:
-                               // replace existing weak external with weak (let dyld decide at runtime which to use)
-                               break;
-                       case kExternWeakAndTent:
-                               // a tentative definition and a dylib definition, so commons-mode decides how to handle
-                               switch ( fOwner.fOptions.commonsMode() ) {
-                                       case Options::kCommonsIgnoreDylibs:
-                                               if ( fOwner.fOptions.warnCommons() )
-                                                       warning("using common symbol %s from %s and ignoring defintion from dylib %s",
-                                                                       newAtom.getName(), newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
-                                               break;
-                                       case Options::kCommonsOverriddenByDylibs:
-                                               if ( fOwner.fOptions.warnCommons() )
-                                                       warning("replacing defintion of %s from dylib %s with common symbol from %s",
-                                                                       newAtom.getName(), existingAtom->getFile()->getPath(), newAtom.getFile()->getPath());
-                                               useNew = false;
-                                               break;
-                                       case Options::kCommonsConflictsDylibsError:
-                                               throwf("common symbol %s from %s conflicts with defintion from dylib %s",
-                                                                       newAtom.getName(), newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
-                               }
-                               break;
-                       case kExternWeakAndExtern:
-                               // replace existing weak external with external
-                               break;
-                       case kExternWeakAndExternWeak:
-                               // keep existing external weak
-                               useNew = false;
-                               break;
-                       case kExternWeakAndAbsolute:
-                               // replace existing weak external with absolute
-                               break;
-                       case kAbsoluteAndReg:
-                               throwf("duplicate symbol %s in %s and %s", name, newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
-                       case kAbsoluteAndWeak:
-                               // ignore new weak atom, because we already have a non-weak one
-                               useNew = false;
-                               break;
-                       case kAbsoluteAndTent:
-                               // ignore new tentative atom, because we already have a regular one
-                               useNew = false;
-                               break;
-                       case kAbsoluteAndExtern:
-                               // ignore external atom, because we already have a one
-                               useNew = false;
-                               break;
-                       case kAbsoluteAndExternWeak:
-                               // ignore external atom, because we already have a one
-                               useNew = false;
-                               break;
-                       case kAbsoluteAndAbsolute:
-                               throwf("duplicate symbol %s in %s and %s", name, newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
-                               break;
-               }
-       }
-       if ( (existingAtom != NULL) && checkVisibilityMismatch && (newAtom.getScope() != existingAtom->getScope()) ) {
-               warning("%s has different visibility (%s) in %s and (%s) in %s", 
-                       newAtom.getDisplayName(), (newAtom.getScope() == 1 ? "hidden" : "default"), newAtom.getFile()->getPath(), (existingAtom->getScope()  == 1 ? "hidden" : "default"), existingAtom->getFile()->getPath());
-       }
-       if ( useNew ) {
-               fTable[name] = &newAtom;
-               if ( existingAtom != NULL ) {
-                       fOwner.markDead(existingAtom);
-                       if ( fOwner.fInitialLoadsDone ) {
-                               //fprintf(stderr, "existing %p %s overridden by %p\n", existingAtom, existingAtom->getName(), &newAtom);
-                               fOwner.fAtomsOverriddenByLateLoads.insert(existingAtom);
-                       }
-               }
-               if ( newAtom.getScope() == ObjectFile::Atom::scopeGlobal ) {
-                       switch ( newAtom.getDefinitionKind() ) {
-                               case ObjectFile::Atom::kTentativeDefinition:
-                                       fHasExternalTentativeDefinitions = true;
-                                       ++fRequireCount; // added a tentative definition means loadUndefines() needs to continue
-                                       break;
-                               case ObjectFile::Atom::kWeakDefinition:
-                                       fHasExternalWeakDefinitions = true;
-                                       break;
-                               default:
-                                       break;
-                       }
-               }
-       }
-       else {
-               fOwner.markDead(&newAtom);
-       }
-       return useNew;
-}
-
-
-
-ObjectFile::Atom* Linker::SymbolTable::find(const char* name)
-{
-       Mapper::iterator pos = fTable.find(name);
-       if ( pos != fTable.end() ) {
-               return pos->second;
-       }
-       return NULL;
-}
-
-
-void Linker::SymbolTable::getUndefinesNames(std::vector<const char*>& undefines)
-{
-       for (Mapper::iterator it=fTable.begin(); it != fTable.end(); it++) {
-               if ( it->second == NULL ) {
-                       undefines.push_back(it->first);
-               }
-       }
-}
-
-void Linker::SymbolTable::getTentativesNames(std::vector<const char*>& tents)
-{
-       for (Mapper::iterator it=fTable.begin(); it != fTable.end(); it++) {
-               if ( it->second != NULL ) {
-                       if ( (it->second->getDefinitionKind() == ObjectFile::Atom::kTentativeDefinition) 
-                                && (it->second->getScope() == ObjectFile::Atom::scopeGlobal) ) {
-                                   tents.push_back(it->first);
-                       }               
-               }
-       }
-}
-
-
-
-bool Linker::AtomSorter::operator()(const ObjectFile::Atom* left, const ObjectFile::Atom* right)
-{
-       if ( left == right )
-               return false;
-
-       // first sort by section order (which is already sorted by segment)
-       unsigned int leftSectionIndex  =  left->getSection()->getIndex();
-       unsigned int rightSectionIndex = right->getSection()->getIndex();
-       if ( leftSectionIndex != rightSectionIndex)
-               return (leftSectionIndex < rightSectionIndex);
-
-       // if a -order_file is specified, then sorting is altered to sort those symbols first
-       if ( fOverriddenOrdinalMap != NULL ) {
-               std::map<const ObjectFile::Atom*, uint32_t>::iterator leftPos  = fOverriddenOrdinalMap->find(left);
-               std::map<const ObjectFile::Atom*, uint32_t>::iterator rightPos = fOverriddenOrdinalMap->find(right);
-               std::map<const ObjectFile::Atom*, uint32_t>::iterator end = fOverriddenOrdinalMap->end();
-               if ( leftPos != end ) {
-                       if ( rightPos != end ) {
-                               // both left and right are overridden, so compare overridden ordinals
-                               return leftPos->second < rightPos->second;
-                       }
-                       else {
-                               // left is overridden and right is not, so left < right
-                               return true;
-                       }
-               }
-               else {
-                       if ( rightPos != end ) {
-                               // right is overridden and left is not, so right < left
-                               return false;
-                       }
-                       else {
-                               // neither are overridden, do default sort
-                               // fall into default sorting below
-                       }
-               }
-       }
-
-       // the __common section can have real or tentative definitions
-       // we want the real ones to sort before tentative ones
-       bool leftIsTent  =  (left->getDefinitionKind() == ObjectFile::Atom::kTentativeDefinition);
-       bool rightIsTent =  (right->getDefinitionKind() == ObjectFile::Atom::kTentativeDefinition);
-       if ( leftIsTent != rightIsTent )
-               return rightIsTent; 
-       
-       // initializers are auto sorted to start of section
-       if ( !fInitializerSet.empty() ) {
-               bool leftFirst  = (fInitializerSet.count(left) != 0);
-               bool rightFirst = (fInitializerSet.count(right) != 0);
-               if ( leftFirst != rightFirst ) 
-                       return leftFirst;
-       }
-
-       // terminators are auto sorted to end of section
-       if ( !fTerminatorSet.empty() ) {
-               bool leftLast  = (fTerminatorSet.count(left) != 0);
-               bool rightLast = (fTerminatorSet.count(right) != 0);
-               if ( leftLast != rightLast ) 
-                       return rightLast;
-       }
-       
-       // lastly sort by atom ordinal.  this is already sorted by .o order
-       return left->getOrdinal() < right->getOrdinal();
+       exit(1);
 }
+#endif
 
 
-int main(int argc, const char* argv[])
-{
-       const char* archName = NULL;
-       bool showArch = false;
-       bool archInferred = false;
-       try {
-               // create linker object given command line arguments
-               Linker ld(argc, argv);
-
-               // save error message prefix
-               archName = ld.architectureName();
-               archInferred = ld.isInferredArchitecture();
-               showArch = ld.showArchitectureInErrors();
-
-               // open all input files
-               ld.createReaders();
-
-               // open output file
-               ld.createWriter();
-
-               // do linking
-               ld.link();
-       }
-       catch (const char* msg) {
-               if ( archInferred )
-                       fprintf(stderr, "ld: %s for inferred architecture %s\n", msg, archName);
-               else if ( showArch )
-                       fprintf(stderr, "ld: %s for architecture %s\n", msg, archName);
-               else
-                       fprintf(stderr, "ld: %s\n", msg);
-               return 1;
-       }
-
-       return 0;
-}