ld64-253.9.tar.gz

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

diff --git a/src/ld/ld.cpp b/src/ld/ld.cpp
index 844f6142521eac5067be1c189bbfa12f774a17b0..0b5bc4a867b4dc821e62f5a6110307415f054d43 100644 (file)
--- a/src/ld/ld.cpp
+++ b/src/ld/ld.cpp
@@ -79,6 +79,7 @@ extern "C" double log2 ( double );
 #include "passes/branch_shim.h"
 #include "passes/objc.h"
 #include "passes/dylibs.h"
 #include "passes/branch_shim.h"
 #include "passes/objc.h"
 #include "passes/dylibs.h"

+#include "passes/bitcode_bundle.h"

 
 #include "parsers/archive_file.h"
 #include "parsers/macho_relocatable_file.h"
 
 #include "parsers/archive_file.h"
 #include "parsers/macho_relocatable_file.h"


@@ -106,25 +107,28 @@ public:
                                                                                        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&);
                                                                                        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&);

+                       ld::Internal::FinalSection*     getFinalSection(const char* seg, const char* sect, ld::Section::Type type);

        
        uint64_t                                                                assignFileOffsets();
        void                                                                    setSectionSizesAndAlignments();
        void                                                                    sortSections();
        void                                                                    markAtomsOrdered() { _atomsOrderedInSections = true; }
        
        uint64_t                                                                assignFileOffsets();
        void                                                                    setSectionSizesAndAlignments();
        void                                                                    sortSections();
        void                                                                    markAtomsOrdered() { _atomsOrderedInSections = true; }

+       bool                                                                    hasReferenceToWeakExternal(const ld::Atom& atom);
+

        virtual                                                                 ~InternalState() {}
 private:
 
        class FinalSection : public ld::Internal::FinalSection 
        {
        public:
        virtual                                                                 ~InternalState() {}
 private:
 
        class FinalSection : public ld::Internal::FinalSection 
        {
        public:

-                                                       FinalSection(const ld::Section& sect, uint32_t sectionsSeen, bool objFile);
+                                                                       FinalSection(const ld::Section& sect, uint32_t sectionsSeen, const Options&);

                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, const Options&);
        private:
                friend class InternalState;
                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, const Options&);
        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);
+               static uint32_t         sectionOrder(const ld::Section& sect, uint32_t sectionsSeen, const Options& options);
+               static uint32_t         segmentOrder(const ld::Section& sect, const Options& options);

                uint32_t                        _segmentOrder;
                uint32_t                        _sectionOrder;
 
                uint32_t                        _segmentOrder;
                uint32_t                        _sectionOrder;
 


@@ -136,6 +140,8 @@ private:
                static ld::Section              _s_DATA_nl_symbol_ptr;
                static ld::Section              _s_DATA_common;
                static ld::Section              _s_DATA_zerofill;
                static ld::Section              _s_DATA_nl_symbol_ptr;
                static ld::Section              _s_DATA_common;
                static ld::Section              _s_DATA_zerofill;

+               static ld::Section              _s_DATA_DIRTY_data;
+               static ld::Section              _s_DATA_CONST_const;

        };
        
        bool hasZeroForFileOffset(const ld::Section* sect);
        };
        
        bool hasZeroForFileOffset(const ld::Section* sect);


@@ -163,6 +169,9 @@ ld::Section InternalState::FinalSection::_s_TEXT_const("__TEXT", "__const", ld::
 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);
 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);

+ld::Section    InternalState::FinalSection::_s_DATA_DIRTY_data( "__DATA_DIRTY", "__data",  ld::Section::typeUnclassified);
+ld::Section    InternalState::FinalSection::_s_DATA_CONST_const( "__DATA_CONST", "__const",  ld::Section::typeUnclassified);
+

 std::vector<const char*> InternalState::FinalSection::_s_segmentsSeen;
 
 
 std::vector<const char*> InternalState::FinalSection::_s_segmentsSeen;
 
 


@@ -181,10 +190,10 @@ bool InternalState::SectionEquals::operator()(const ld::Section* left, const ld:
 }
 
 
 }
 
 

-InternalState::FinalSection::FinalSection(const ld::Section& sect, uint32_t sectionsSeen, bool objFile)
+InternalState::FinalSection::FinalSection(const ld::Section& sect, uint32_t sectionsSeen, const Options& opts)

        : ld::Internal::FinalSection(sect), 
        : ld::Internal::FinalSection(sect), 

-         _segmentOrder(segmentOrder(sect, objFile)),
-         _sectionOrder(sectionOrder(sect, sectionsSeen))
+         _segmentOrder(segmentOrder(sect, opts)),
+         _sectionOrder(sectionOrder(sect, sectionsSeen, opts))

 {
        //fprintf(stderr, "FinalSection(%s, %s) _segmentOrder=%d, _sectionOrder=%d\n", 
        //              this->segmentName(), this->sectionName(), _segmentOrder, _sectionOrder);
 {
        //fprintf(stderr, "FinalSection(%s, %s) _segmentOrder=%d, _sectionOrder=%d\n", 
        //              this->segmentName(), this->sectionName(), _segmentOrder, _sectionOrder);


@@ -197,7 +206,9 @@ const ld::Section& InternalState::FinalSection::outputSection(const ld::Section&
                case ld::Section::typeLiteral4:
                case ld::Section::typeLiteral8:
                case ld::Section::typeLiteral16:
                case ld::Section::typeLiteral4:
                case ld::Section::typeLiteral8:
                case ld::Section::typeLiteral16:

-                       return _s_TEXT_const;
+                       if ( strcmp(sect.segmentName(), "__TEXT") == 0 )
+                               return _s_TEXT_const;
+                       break;

                case ld::Section::typeUnclassified:
                        if ( strcmp(sect.segmentName(), "__DATA") == 0 ) {
                                if ( strcmp(sect.sectionName(), "__datacoal_nt") == 0 )
                case ld::Section::typeUnclassified:
                        if ( strcmp(sect.segmentName(), "__DATA") == 0 ) {
                                if ( strcmp(sect.sectionName(), "__datacoal_nt") == 0 )


@@ -209,6 +220,14 @@ const ld::Section& InternalState::FinalSection::outputSection(const ld::Section&
                                if ( strcmp(sect.sectionName(), "__const_coal") == 0 )
                                        return _s_TEXT_const;
                        }
                                if ( strcmp(sect.sectionName(), "__const_coal") == 0 )
                                        return _s_TEXT_const;
                        }

+                       else if ( strcmp(sect.segmentName(), "__DATA_DIRTY") == 0 ) {
+                               if ( strcmp(sect.sectionName(), "__datacoal_nt") == 0 )
+                                       return _s_DATA_DIRTY_data;
+                       }
+                       else if ( strcmp(sect.segmentName(), "__DATA_CONST") == 0 ) {
+                               if ( strcmp(sect.sectionName(), "__const_coal") == 0 )
+                                       return _s_DATA_CONST_const;
+                       }

                        break;
                case ld::Section::typeZeroFill:
                        if ( mergeZeroFill )
                        break;
                case ld::Section::typeZeroFill:
                        if ( mergeZeroFill )


@@ -233,10 +252,12 @@ const ld::Section& InternalState::FinalSection::outputSection(const ld::Section&
                        }
                        break;
                case ld::Section::typeTentativeDefs:
                        }
                        break;
                case ld::Section::typeTentativeDefs:

-                       if ( mergeZeroFill )
-                               return _s_DATA_zerofill;
-                       else
-                               return _s_DATA_common;
+                       if ( (strcmp(sect.segmentName(), "__DATA") == 0) && (strcmp(sect.sectionName(), "__comm/tent") == 0) ) {
+                               if ( mergeZeroFill )
+                                       return _s_DATA_zerofill;
+                               else
+                                       return _s_DATA_common;
+                       }

                        break;
                        // FIX ME: more 
                default:
                        break;
                        // FIX ME: more 
                default:


@@ -247,47 +268,50 @@ const ld::Section& InternalState::FinalSection::outputSection(const ld::Section&
 
 const ld::Section& InternalState::FinalSection::objectOutputSection(const ld::Section& sect, const Options& options)
 {
 
 const ld::Section& InternalState::FinalSection::objectOutputSection(const ld::Section& sect, const Options& options)
 {

-       const std::vector<Options::SectionRename>& renames = options.sectionRenames();
-       for ( std::vector<Options::SectionRename>::const_iterator it=renames.begin(); it != renames.end(); ++it) {
-         if ( (strcmp(sect.sectionName(), it->fromSection) == 0) && (strcmp(sect.segmentName(), it->fromSegment) == 0) ) {
-               ld::Section* s = new ld::Section(it->toSegment, it->toSection, sect.type());
-               return *s;
-         }
-       }
-
-

        // in -r mode the only section that ever changes is __tenative -> __common with -d option
        if ( (sect.type() == ld::Section::typeTentativeDefs) && options.makeTentativeDefinitionsReal())
                return _s_DATA_common;
        return sect;
 }
 
        // in -r mode the only section that ever changes is __tenative -> __common with -d option
        if ( (sect.type() == ld::Section::typeTentativeDefs) && options.makeTentativeDefinitionsReal())
                return _s_DATA_common;
        return sect;
 }
 

-uint32_t InternalState::FinalSection::segmentOrder(const ld::Section& sect, bool objFile)
+uint32_t InternalState::FinalSection::segmentOrder(const ld::Section& sect, const Options& options)

 {
 {

-       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)
+       if ( options.outputKind() == Options::kPreload ) {
+               if ( strcmp(sect.segmentName(), "__HEADER") == 0 ) 
+                       return 0;
+               const std::vector<const char*>& order = options.segmentOrder();
+               for (size_t i=0; i != order.size(); ++i) {
+                       if ( strcmp(sect.segmentName(), order[i]) == 0 ) 
+                               return i+1;
+               }
+               if ( strcmp(sect.segmentName(), "__TEXT") == 0 ) 
+                       return order.size()+1;
+               if ( strcmp(sect.segmentName(), "__DATA") == 0 ) 
+                       return order.size()+2;
+       }
+       else {
+               if ( strcmp(sect.segmentName(), "__PAGEZERO") == 0 ) 
+                       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 (options.outputKind() == Options::kObjectFile) ? 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 (+100 to shift beyond standard segments)

        for (uint32_t i=0; i < _s_segmentsSeen.size(); ++i) {
                if ( strcmp(_s_segmentsSeen[i], sect.segmentName()) == 0 )
        for (uint32_t i=0; i < _s_segmentsSeen.size(); ++i) {
                if ( strcmp(_s_segmentsSeen[i], sect.segmentName()) == 0 )

-                       return i+10;
+                       return i+100;

        }
        _s_segmentsSeen.push_back(sect.segmentName());
        }
        _s_segmentsSeen.push_back(sect.segmentName());

-       return _s_segmentsSeen.size()-1+10;
+       return _s_segmentsSeen.size()-1+100;

 }
 
 }
 

-uint32_t InternalState::FinalSection::sectionOrder(const ld::Section& sect, uint32_t sectionsSeen)
+uint32_t InternalState::FinalSection::sectionOrder(const ld::Section& sect, uint32_t sectionsSeen, const Options& options)

 {
        if ( sect.type() == ld::Section::typeFirstSection )
                return 0;
 {
        if ( sect.type() == ld::Section::typeFirstSection )
                return 0;


@@ -295,6 +319,14 @@ uint32_t InternalState::FinalSection::sectionOrder(const ld::Section& sect, uint
                return 1;
        if ( sect.type() == ld::Section::typeLastSection )
                return INT_MAX;
                return 1;
        if ( sect.type() == ld::Section::typeLastSection )
                return INT_MAX;

+       const std::vector<const char*>* sectionList = options.sectionOrder(sect.segmentName());
+       if ( ((options.outputKind() == Options::kPreload) || (options.outputKind() == Options::kDyld)) && (sectionList != NULL) ) {
+               uint32_t count = 10;
+               for (std::vector<const char*>::const_iterator it=sectionList->begin(); it != sectionList->end(); ++it, ++count) {
+                       if ( strcmp(*it, sect.sectionName()) == 0 ) 
+                               return count;
+               }
+       }

        if ( strcmp(sect.segmentName(), "__TEXT") == 0 ) {
                switch ( sect.type() ) {
                        case ld::Section::typeCode:
        if ( strcmp(sect.segmentName(), "__TEXT") == 0 ) {
                switch ( sect.type() ) {
                        case ld::Section::typeCode:


@@ -319,7 +351,7 @@ uint32_t InternalState::FinalSection::sectionOrder(const ld::Section& sect, uint
                                return sectionsSeen+20;
                }
        }
                                return sectionsSeen+20;
                }
        }

-       else if ( strcmp(sect.segmentName(), "__DATA") == 0 ) {
+       else if ( strncmp(sect.segmentName(), "__DATA", 6) == 0 ) {

                switch ( sect.type() ) {
                        case ld::Section::typeLazyPointerClose:
                                return 8;
                switch ( sect.type() ) {
                        case ld::Section::typeLazyPointerClose:
                                return 8;


@@ -347,6 +379,9 @@ uint32_t InternalState::FinalSection::sectionOrder(const ld::Section& sect, uint
                                // <rdar://problem/14348664> __DATA,__const section should be near __mod_init_func not __data
                                if ( strcmp(sect.sectionName(), "__const") == 0 )
                                        return 14;
                                // <rdar://problem/14348664> __DATA,__const section should be near __mod_init_func not __data
                                if ( strcmp(sect.sectionName(), "__const") == 0 )
                                        return 14;

+                               // <rdar://problem/17125893> Linker should put __cfstring near __const
+                               if ( strcmp(sect.sectionName(), "__cfstring") == 0 )
+                                       return 15;

                                // <rdar://problem/7435296> Reorder sections to reduce page faults in object files
                                else if ( strcmp(sect.sectionName(), "__objc_classlist") == 0 ) 
                                        return 20;
                                // <rdar://problem/7435296> Reorder sections to reduce page faults in object files
                                else if ( strcmp(sect.sectionName(), "__objc_classlist") == 0 ) 
                                        return 20;


@@ -354,24 +389,28 @@ uint32_t InternalState::FinalSection::sectionOrder(const ld::Section& sect, uint
                                        return 21;
                                else if ( strcmp(sect.sectionName(), "__objc_catlist") == 0 ) 
                                        return 22;
                                        return 21;
                                else if ( strcmp(sect.sectionName(), "__objc_catlist") == 0 ) 
                                        return 22;

-                               else if ( strcmp(sect.sectionName(), "__objc_protolist") == 0 ) 
+                               else if ( strcmp(sect.sectionName(), "__objc_nlcatlist") == 0 ) 

                                        return 23;
                                        return 23;

-                               else if ( strcmp(sect.sectionName(), "__objc_imageinfo") == 0 ) 
+                               else if ( strcmp(sect.sectionName(), "__objc_protolist") == 0 ) 

                                        return 24;
                                        return 24;

-                               else if ( strcmp(sect.sectionName(), "__objc_const") == 0 ) 
+                               else if ( strcmp(sect.sectionName(), "__objc_imageinfo") == 0 ) 

                                        return 25;
                                        return 25;

-                               else if ( strcmp(sect.sectionName(), "__objc_selrefs") == 0 ) 
+                               else if ( strcmp(sect.sectionName(), "__objc_const") == 0 ) 

                                        return 26;
                                        return 26;

-                               else if ( strcmp(sect.sectionName(), "__objc_msgrefs") == 0 ) 
+                               else if ( strcmp(sect.sectionName(), "__objc_selrefs") == 0 ) 

                                        return 27;
                                        return 27;

-                               else if ( strcmp(sect.sectionName(), "__objc_protorefs") == 0 ) 
+                               else if ( strcmp(sect.sectionName(), "__objc_msgrefs") == 0 ) 

                                        return 28;
                                        return 28;

-                               else if ( strcmp(sect.sectionName(), "__objc_classrefs") == 0 ) 
+                               else if ( strcmp(sect.sectionName(), "__objc_protorefs") == 0 ) 

                                        return 29;
                                        return 29;

-                               else if ( strcmp(sect.sectionName(), "__objc_superrefs") == 0 ) 
+                               else if ( strcmp(sect.sectionName(), "__objc_classrefs") == 0 ) 

                                        return 30;
                                        return 30;

-                               else if ( strcmp(sect.sectionName(), "__objc_data") == 0 ) 
+                               else if ( strcmp(sect.sectionName(), "__objc_superrefs") == 0 ) 

                                        return 31;
                                        return 31;

+                               else if ( strcmp(sect.sectionName(), "__objc_ivar") == 0 ) 
+                                       return 32;
+                               else if ( strcmp(sect.sectionName(), "__objc_data") == 0 ) 
+                                       return 33;

                                else
                                        return sectionsSeen+40;
                }
                                else
                                        return sectionsSeen+40;
                }


@@ -469,9 +508,125 @@ static void validateFixups(const ld::Atom& atom)
 }
 #endif
 
 }
 #endif
 

+bool InternalState::hasReferenceToWeakExternal(const ld::Atom& atom)
+{
+       // if __DATA,__const atom has pointer to weak external symbol, don't move to __DATA_CONST
+       const ld::Atom* target = NULL;
+       for (ld::Fixup::iterator fit=atom.fixupsBegin(); fit != atom.fixupsEnd(); ++fit) {
+               if ( fit->firstInCluster() ) {
+                       target = NULL;
+               }
+               switch ( fit->binding ) {
+                       case ld::Fixup::bindingNone:
+                       case ld::Fixup::bindingByNameUnbound:
+                               break;
+                       case ld::Fixup::bindingByContentBound:
+                       case ld::Fixup::bindingDirectlyBound:
+                               target = fit->u.target;
+                               break;
+                       case ld::Fixup::bindingsIndirectlyBound:
+                               target = indirectBindingTable[fit->u.bindingIndex];
+                               break;
+               }
+               if ( (target != NULL) && (target->definition() == ld::Atom::definitionRegular)
+                       && (target->combine() == ld::Atom::combineByName) && (target->scope() == ld::Atom::scopeGlobal) ) {
+                       return true;
+               }
+       }
+       return false;
+}
+

 ld::Internal::FinalSection* InternalState::addAtom(const ld::Atom& atom)
 {
 ld::Internal::FinalSection* InternalState::addAtom(const ld::Atom& atom)
 {

-       ld::Internal::FinalSection* fs = this->getFinalSection(atom.section());
+       ld::Internal::FinalSection* fs = NULL;
+       const char* sectName = atom.section().sectionName();
+       ld::Section::Type sectType = atom.section().type();
+       const ld::File* f = atom.file();
+       const char* path = (f != NULL) ? f->path() : NULL;
+       if ( atom.section().type() == ld::Section::typeTentativeDefs ) {
+               // tentative defintions don't have a real section name yet
+               sectType = ld::Section::typeZeroFill;
+               if ( _options.mergeZeroFill() )
+                       sectName = FinalSection::_s_DATA_zerofill.sectionName();
+               else
+                       sectName = FinalSection::_s_DATA_common.sectionName();
+       }
+       // Support for -move_to_r._segment
+       if ( atom.symbolTableInclusion() == ld::Atom::symbolTableIn ) {
+               const char* dstSeg;
+               //fprintf(stderr, "%s\n", atom.name());
+               bool wildCardMatch;
+               if ( _options.moveRwSymbol(atom.name(), path, dstSeg, wildCardMatch) ) {
+                       if ( (sectType != ld::Section::typeZeroFill) 
+                         && (sectType != ld::Section::typeUnclassified) 
+                         && (sectType != ld::Section::typeTentativeDefs)
+                         && (sectType != ld::Section::typeDyldInfo) ) {
+                               if ( !wildCardMatch )
+                                       warning("cannot move symbol '%s' from file %s to segment '%s' because symbol is not data (is %d)", atom.name(), path, dstSeg, sectType);
+                       }
+                       else {
+                               if ( _options.traceSymbolLayout() )
+                                       printf("symbol '%s', -move_to_rw_segment mapped it to %s/%s\n", atom.name(), dstSeg, sectName);
+                               fs = this->getFinalSection(dstSeg, sectName, sectType);
+                       }
+               }
+               if ( (fs == NULL) && _options.moveRoSymbol(atom.name(), path, dstSeg, wildCardMatch) ) {
+                       if ( (sectType != ld::Section::typeCode)
+                         && (sectType != ld::Section::typeUnclassified) ) {
+                               if ( !wildCardMatch )
+                                       warning("cannot move symbol '%s' from file %s to segment '%s' because symbol is not code (is %d)", atom.name(), path, dstSeg, sectType);
+                       }
+                       else {
+                               if ( _options.traceSymbolLayout() )
+                                       printf("symbol '%s', -move_to_ro_segment mapped it to %s/%s\n", atom.name(), dstSeg, sectName);
+                               fs = this->getFinalSection(dstSeg, sectName, ld::Section::typeCode);
+                       }
+               }
+       }
+       // support for -rename_section and -rename_segment
+       if ( fs == NULL ) {
+               const std::vector<Options::SectionRename>& sectRenames = _options.sectionRenames();
+               const std::vector<Options::SegmentRename>& segRenames = _options.segmentRenames();
+               for ( std::vector<Options::SectionRename>::const_iterator it=sectRenames.begin(); it != sectRenames.end(); ++it) {
+                       if ( (strcmp(sectName, it->fromSection) == 0) && (strcmp(atom.section().segmentName(), it->fromSegment) == 0) ) {
+                               if ( _options.useDataConstSegment() && (strcmp(sectName, "__const") == 0)
+                                               && (strcmp(atom.section().segmentName(), "__DATA") == 0) && hasReferenceToWeakExternal(atom) ) {
+                                       // if __DATA,__const atom has pointer to weak external symbol, don't move to __DATA_CONST
+                                       fs = this->getFinalSection("__DATA", "__const_weak", sectType);
+                                       if ( _options.traceSymbolLayout() )
+                                               printf("symbol '%s', contains pointers to weak symbols, so mapped it to __DATA/_const_weak\n", atom.name());
+                               }
+                               else if ( _options.useDataConstSegment() && (sectType == ld::Section::typeNonLazyPointer) && hasReferenceToWeakExternal(atom) ) {
+                                       // if __DATA,__nl_symbol_ptr atom has pointer to weak external symbol, don't move to __DATA_CONST
+                                       fs = this->getFinalSection("__DATA", "__got_weak", sectType);
+                                       if ( _options.traceSymbolLayout() )
+                                               printf("symbol '%s', contains pointers to weak symbols, so mapped it to __DATA/__got_weak\n", atom.name());
+                               }
+                               else {
+                                       fs = this->getFinalSection(it->toSegment, it->toSection, sectType);
+                                       if ( _options.traceSymbolLayout() )
+                                               printf("symbol '%s', -rename_section mapped it to %s/%s\n", atom.name(), fs->segmentName(), fs->sectionName());
+                               }
+                       }
+               }
+               if ( fs == NULL ) {
+                       for ( std::vector<Options::SegmentRename>::const_iterator it=segRenames.begin(); it != segRenames.end(); ++it) {
+                               if ( strcmp(atom.section().segmentName(), it->fromSegment) == 0 ) {
+                                       if ( _options.traceSymbolLayout() )
+                                               printf("symbol '%s', -rename_segment mapped it to %s/%s\n", atom.name(), it->toSegment, sectName);
+                                       fs = this->getFinalSection(it->toSegment, sectName, sectType);
+                               }
+                       }
+               }
+       }
+
+       // if no override, use default location
+       if ( fs == NULL ) {
+               fs = this->getFinalSection(atom.section());
+               if ( _options.traceSymbolLayout() && (atom.symbolTableInclusion() == ld::Atom::symbolTableIn) )
+                       printf("symbol '%s', use default mapping to %s/%s\n", atom.name(), fs->segmentName(), fs->sectionName());
+       }
+

        //fprintf(stderr, "InternalState::doAtom(%p), name=%s, sect=%s, finalsect=%p\n", &atom, atom.name(), atom.section().sectionName(), fs);
 #ifndef NDEBUG
        validateFixups(atom);
        //fprintf(stderr, "InternalState::doAtom(%p), name=%s, sect=%s, finalsect=%p\n", &atom, atom.name(), atom.section().sectionName(), fs);
 #ifndef NDEBUG
        validateFixups(atom);


@@ -494,9 +649,21 @@ ld::Internal::FinalSection* InternalState::addAtom(const ld::Atom& atom)
                // normal case
                fs->atoms.push_back(&atom);
        }
                // normal case
                fs->atoms.push_back(&atom);
        }

+       this->atomToSection[&atom] = fs;

        return fs;
 }
 
        return fs;
 }
 

+
+
+ld::Internal::FinalSection* InternalState::getFinalSection(const char* seg, const char* sect, ld::Section::Type type)
+{      
+       for (std::vector<ld::Internal::FinalSection*>::iterator it=sections.begin(); it != sections.end(); ++it) {
+               if ( (strcmp((*it)->segmentName(),seg) == 0) && (strcmp((*it)->sectionName(),sect) == 0) )
+                       return *it;
+       }
+       return this->getFinalSection(*new ld::Section(seg, sect, type, false));
+}
+

 ld::Internal::FinalSection* InternalState::getFinalSection(const ld::Section& inputSection)
 {      
        const ld::Section* baseForFinalSection = &inputSection;
 ld::Internal::FinalSection* InternalState::getFinalSection(const ld::Section& inputSection)
 {      
        const ld::Section* baseForFinalSection = &inputSection;


@@ -508,7 +675,6 @@ ld::Internal::FinalSection* InternalState::getFinalSection(const ld::Section& in
        }
 
        // otherwise, create a new final section
        }
 
        // otherwise, create a new final section

-       bool objFile = false;

        switch ( _options.outputKind() ) {
                case Options::kStaticExecutable:
                case Options::kDynamicExecutable:
        switch ( _options.outputKind() ) {
                case Options::kStaticExecutable:
                case Options::kDynamicExecutable:


@@ -540,14 +706,13 @@ ld::Internal::FinalSection* InternalState::getFinalSection(const ld::Section& in
                                //fprintf(stderr, "_sectionInToFinalMap[%p] = %p\n", &inputSection, pos->second);
                                return pos->second;
                        }
                                //fprintf(stderr, "_sectionInToFinalMap[%p] = %p\n", &inputSection, pos->second);
                                return pos->second;
                        }

-                       objFile = true;

                        break;
        }
 
        InternalState::FinalSection* result = new InternalState::FinalSection(*baseForFinalSection, 
                        break;
        }
 
        InternalState::FinalSection* result = new InternalState::FinalSection(*baseForFinalSection, 

-                                                                                                                                       _sectionInToFinalMap.size(), objFile);
+                                                                                                                                       _sectionInToFinalMap.size(), _options);

        _sectionInToFinalMap[baseForFinalSection] = result;
        _sectionInToFinalMap[baseForFinalSection] = result;

-       //fprintf(stderr, "_sectionInToFinalMap[%p] = %p\n", baseForFinalSection, result);
+       //fprintf(stderr, "_sectionInToFinalMap[%p(%s)] = %p\n", baseForFinalSection, baseForFinalSection->sectionName(), result);

        sections.push_back(result);
        return result;
 }
        sections.push_back(result);
        return result;
 }


@@ -627,7 +792,7 @@ void InternalState::setSectionSizesAndAlignments()
                                bool pagePerAtom = false;
                                uint32_t atomAlignmentPowerOf2 = atom->alignment().powerOf2;
                                uint32_t atomModulus = atom->alignment().modulus;
                                bool pagePerAtom = false;
                                uint32_t atomAlignmentPowerOf2 = atom->alignment().powerOf2;
                                uint32_t atomModulus = atom->alignment().modulus;

-                               if ( _options.pageAlignDataAtoms() && ( strcmp(atom->section().segmentName(), "__DATA") == 0) ) { 
+                               if ( _options.pageAlignDataAtoms() && ( strncmp(atom->section().segmentName(), "__DATA", 6) == 0) ) {

                                        // most objc sections cannot be padded
                                        bool contiguousObjCSection = ( strncmp(atom->section().sectionName(), "__objc_", 7) == 0 );
                                        if ( strcmp(atom->section().sectionName(), "__objc_const") == 0 )
                                        // most objc sections cannot be padded
                                        bool contiguousObjCSection = ( strncmp(atom->section().sectionName(), "__objc_", 7) == 0 );
                                        if ( strcmp(atom->section().sectionName(), "__objc_const") == 0 )


@@ -707,13 +872,22 @@ uint64_t InternalState::assignFileOffsets()
        uint64_t address = 0;
        const char* lastSegName = "";
        uint64_t floatingAddressStart = _options.baseAddress();
        uint64_t address = 0;
        const char* lastSegName = "";
        uint64_t floatingAddressStart = _options.baseAddress();

+       bool haveFixedSegments = false;

        
        

+       // mark all sections as not having an address yet
+       for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
+               ld::Internal::FinalSection* sect = *it;
+               sect->alignmentPaddingBytes = 0;
+               sect->address = ULLONG_MAX;
+       }
+

        // first pass, assign addresses to sections in segments with fixed start addresses
        if ( log ) fprintf(stderr, "Fixed address segments:\n");
        for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
                ld::Internal::FinalSection* sect = *it;
                if ( ! _options.hasCustomSegmentAddress(sect->segmentName()) ) 
                        continue;
        // first pass, assign addresses to sections in segments with fixed start addresses
        if ( log ) fprintf(stderr, "Fixed address segments:\n");
        for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
                ld::Internal::FinalSection* sect = *it;
                if ( ! _options.hasCustomSegmentAddress(sect->segmentName()) ) 
                        continue;

+               haveFixedSegments = true;

                if ( segmentsArePageAligned ) {
                        if ( strcmp(lastSegName, sect->segmentName()) != 0 ) {
                                address = _options.customSegmentAddress(sect->segmentName());
                if ( segmentsArePageAligned ) {
                        if ( strcmp(lastSegName, sect->segmentName()) != 0 ) {
                                address = _options.customSegmentAddress(sect->segmentName());


@@ -746,8 +920,38 @@ uint64_t InternalState::assignFileOffsets()
                        floatingAddressStart = address;
                }
        }
                        floatingAddressStart = address;
                }
        }

-       
-       // second pass, assign section address to sections in segments that are contiguous with previous segment
+
+       // second pass, assign section addresses to sections in segments that are ordered after a segment with a fixed address
+       if ( haveFixedSegments && !_options.segmentOrder().empty() ) {
+               if ( log ) fprintf(stderr, "After Fixed address segments:\n");
+               lastSegName = "";
+               ld::Internal::FinalSection* lastSect = NULL; 
+               for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
+                       ld::Internal::FinalSection* sect = *it;
+                       if ( (sect->address == ULLONG_MAX) && _options.segmentOrderAfterFixedAddressSegment(sect->segmentName()) ) {
+                               address = lastSect->address + lastSect->size;
+                               if ( (strcmp(lastSegName, sect->segmentName()) != 0) && segmentsArePageAligned ) {
+                                       // round up size of last segment
+                                       address = pageAlign(address, _options.segPageSize(lastSegName));
+                               }
+                               // adjust section address based on alignment
+                               uint64_t unalignedAddress = address;
+                               uint64_t alignment = (1 << sect->alignment);
+                               address = ( (unalignedAddress+alignment-1) & (-alignment) );
+                               sect->alignmentPaddingBytes = (address - unalignedAddress);
+                               sect->address = address;
+                               if ( log ) fprintf(stderr, "  address=0x%08llX, hidden=%d, alignment=%02d, section=%s,%s\n",
+                                                                       sect->address, sect->isSectionHidden(), sect->alignment, sect->segmentName(), sect->sectionName());
+                               // update running totals
+                               if ( !sect->isSectionHidden() || hiddenSectionsOccupyAddressSpace )
+                                       address += sect->size;
+                       }
+                       lastSegName = sect->segmentName();
+                       lastSect = sect;
+               }
+       }
+
+       // last pass, assign addresses to remaining sections

        address = floatingAddressStart;
        lastSegName = "";
        ld::Internal::FinalSection* overlappingFixedSection = NULL;
        address = floatingAddressStart;
        lastSegName = "";
        ld::Internal::FinalSection* overlappingFixedSection = NULL;


@@ -755,7 +959,7 @@ uint64_t InternalState::assignFileOffsets()
        if ( log ) fprintf(stderr, "Regular layout segments:\n");
        for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
                ld::Internal::FinalSection* sect = *it;
        if ( log ) fprintf(stderr, "Regular layout segments:\n");
        for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
                ld::Internal::FinalSection* sect = *it;

-               if ( _options.hasCustomSegmentAddress(sect->segmentName()) ) 
+               if ( sect->address != ULLONG_MAX )

                        continue;
                if ( (_options.outputKind() == Options::kPreload) && (sect->type() == ld::Section::typeMachHeader) ) {
                        sect->alignmentPaddingBytes = 0;
                        continue;
                if ( (_options.outputKind() == Options::kPreload) && (sect->type() == ld::Section::typeMachHeader) ) {
                        sect->alignmentPaddingBytes = 0;


@@ -772,6 +976,7 @@ uint64_t InternalState::assignFileOffsets()
                                lastSegName = sect->segmentName();
                        }
                }
                                lastSegName = sect->segmentName();
                        }
                }

+               

                // adjust section address based on alignment
                uint64_t unalignedAddress = address;
                uint64_t alignment = (1 << sect->alignment);
                // adjust section address based on alignment
                uint64_t unalignedAddress = address;
                uint64_t alignment = (1 << sect->alignment);


@@ -792,6 +997,10 @@ uint64_t InternalState::assignFileOffsets()
                        ld::Internal::FinalSection* otherSect = *sit;
                        if ( ! _options.hasCustomSegmentAddress(otherSect->segmentName()) ) 
                                continue;
                        ld::Internal::FinalSection* otherSect = *sit;
                        if ( ! _options.hasCustomSegmentAddress(otherSect->segmentName()) ) 
                                continue;

+                       if ( otherSect->size == 0 )
+                               continue;
+                       if ( sect->size == 0 )
+                               continue;

                        if ( sect->address > otherSect->address ) {
                                if ( (otherSect->address+otherSect->size) > sect->address ) {
                                        overlappingFixedSection = otherSect;
                        if ( sect->address > otherSect->address ) {
                                if ( (otherSect->address+otherSect->size) > sect->address ) {
                                        overlappingFixedSection = otherSect;


@@ -817,8 +1026,8 @@ uint64_t InternalState::assignFileOffsets()
                fprintf(stderr, "Section layout:\n");
                for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
                        ld::Internal::FinalSection* sect = *it;
                fprintf(stderr, "Section layout:\n");
                for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
                        ld::Internal::FinalSection* sect = *it;

-                       if ( sect->isSectionHidden() )
-                               continue;
+                       //if ( sect->isSectionHidden() )
+                       //      continue;

                        fprintf(stderr, "  address:0x%08llX, alignment:2^%d, size:0x%08llX, padBytes:%d, section:%s/%s\n",
                                                        sect->address, sect->alignment, sect->size, sect->alignmentPaddingBytes, 
                                                        sect->segmentName(), sect->sectionName());
                        fprintf(stderr, "  address:0x%08llX, alignment:2^%d, size:0x%08llX, padBytes:%d, section:%s/%s\n",
                                                        sect->address, sect->alignment, sect->size, sect->alignmentPaddingBytes, 
                                                        sect->segmentName(), sect->sectionName());


@@ -1008,7 +1217,8 @@ int main(int argc, const char* argv[])
                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
                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

-               
+               ld::passes::bitcode_bundle::doPass(options, state);  // must be after dylib
+               

                // sort final sections
                state.sortSections();
 
                // sort final sections
                state.sortSections();