X-Git-Url: https://git.saurik.com/apple/ld64.git/blobdiff_plain/599556ff3dd31aab68bb9685f1ed7fc4867803e7..fb9a160cc46cd88a41dda5ab61012c5572e56f33:/src/ld/ld.cpp diff --git a/src/ld/ld.cpp b/src/ld/ld.cpp index 4ef1f14..0b5bc4a 100644 --- 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/bitcode_bundle.h" #include "parsers/archive_file.h" #include "parsers/macho_relocatable_file.h" @@ -112,6 +113,8 @@ public: void setSectionSizesAndAlignments(); void sortSections(); void markAtomsOrdered() { _atomsOrderedInSections = true; } + bool hasReferenceToWeakExternal(const ld::Atom& atom); + virtual ~InternalState() {} private: @@ -137,6 +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_DIRTY_data; + static ld::Section _s_DATA_CONST_const; }; bool hasZeroForFileOffset(const ld::Section* sect); @@ -164,6 +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_DIRTY_data( "__DATA_DIRTY", "__data", ld::Section::typeUnclassified); +ld::Section InternalState::FinalSection::_s_DATA_CONST_const( "__DATA_CONST", "__const", ld::Section::typeUnclassified); + std::vector InternalState::FinalSection::_s_segmentsSeen; @@ -212,6 +220,14 @@ const ld::Section& InternalState::FinalSection::outputSection(const ld::Section& 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 ) @@ -304,7 +320,7 @@ uint32_t InternalState::FinalSection::sectionOrder(const ld::Section& sect, uint if ( sect.type() == ld::Section::typeLastSection ) return INT_MAX; const std::vector* sectionList = options.sectionOrder(sect.segmentName()); - if ( (options.outputKind() == Options::kPreload) && (sectionList != NULL) ) { + if ( ((options.outputKind() == Options::kPreload) || (options.outputKind() == Options::kDyld)) && (sectionList != NULL) ) { uint32_t count = 10; for (std::vector::const_iterator it=sectionList->begin(); it != sectionList->end(); ++it, ++count) { if ( strcmp(*it, sect.sectionName()) == 0 ) @@ -335,7 +351,7 @@ uint32_t InternalState::FinalSection::sectionOrder(const ld::Section& sect, uint 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; @@ -492,6 +508,34 @@ static void validateFixups(const ld::Atom& atom) } #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* fs = NULL; @@ -515,7 +559,8 @@ ld::Internal::FinalSection* InternalState::addAtom(const ld::Atom& atom) if ( _options.moveRwSymbol(atom.name(), path, dstSeg, wildCardMatch) ) { if ( (sectType != ld::Section::typeZeroFill) && (sectType != ld::Section::typeUnclassified) - && (sectType != ld::Section::typeTentativeDefs) ) { + && (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); } @@ -526,7 +571,8 @@ ld::Internal::FinalSection* InternalState::addAtom(const ld::Atom& atom) } } if ( (fs == NULL) && _options.moveRoSymbol(atom.name(), path, dstSeg, wildCardMatch) ) { - if ( atom.section().type() != ld::Section::typeCode ) { + 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); } @@ -543,9 +589,24 @@ ld::Internal::FinalSection* InternalState::addAtom(const ld::Atom& atom) const std::vector& segRenames = _options.segmentRenames(); for ( std::vector::const_iterator it=sectRenames.begin(); it != sectRenames.end(); ++it) { if ( (strcmp(sectName, it->fromSection) == 0) && (strcmp(atom.section().segmentName(), it->fromSegment) == 0) ) { - if ( _options.traceSymbolLayout() ) - printf("symbol '%s', -rename_section mapped it to %s/%s\n", atom.name(), it->toSegment, it->toSection); - fs = this->getFinalSection(it->toSegment, it->toSection, sectType); + 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 ) { @@ -558,8 +619,7 @@ ld::Internal::FinalSection* InternalState::addAtom(const ld::Atom& atom) } } } - - + // if no override, use default location if ( fs == NULL ) { fs = this->getFinalSection(atom.section()); @@ -589,6 +649,7 @@ ld::Internal::FinalSection* InternalState::addAtom(const ld::Atom& atom) // normal case fs->atoms.push_back(&atom); } + this->atomToSection[&atom] = fs; return fs; } @@ -731,7 +792,7 @@ void InternalState::setSectionSizesAndAlignments() 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 ) @@ -811,13 +872,22 @@ uint64_t InternalState::assignFileOffsets() 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::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::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()); @@ -850,8 +920,38 @@ uint64_t InternalState::assignFileOffsets() 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::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; @@ -859,7 +959,7 @@ uint64_t InternalState::assignFileOffsets() if ( log ) fprintf(stderr, "Regular layout segments:\n"); for (std::vector::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; @@ -876,6 +976,7 @@ uint64_t InternalState::assignFileOffsets() lastSegName = sect->segmentName(); } } + // adjust section address based on alignment uint64_t unalignedAddress = address; uint64_t alignment = (1 << sect->alignment); @@ -1116,7 +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::bitcode_bundle::doPass(options, state); // must be after dylib + // sort final sections state.sortSections();