/* -*- 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@
*
// start temp HACK for cross builds
extern "C" double log2 ( double );
-#define __MATH__
+//#define __MATH__
// end temp HACK for cross builds
#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>
#include <vector>
#include <list>
#include <algorithm>
-#include <ext/hash_map>
-#include <dlfcn.h>
-#include <AvailabilityMacros.h>
+#include <unordered_map>
+#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 "OpaqueSection.hpp"
-
-
-class CStringComparor
-{
-public:
- bool operator()(const char* left, const char* right) const { return (strcmp(left, right) < 0); }
+#include "MachOFileAbstraction.hpp"
+#include "Architectures.hpp"
+#include "ld.hpp"
+
+#include "InputFiles.h"
+#include "Resolver.h"
+#include "OutputFile.h"
+#include "Snapshot.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 "passes/bitcode_bundle.h"
+#include "passes/code_dedup.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;
};
-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 untrustedZeroFill, bool createIfNeeded=true);
- static void assignIndexes(bool objfile);
- 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&);
+ 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; }
+ bool hasReferenceToWeakExternal(const ld::Atom& atom);
+
+ virtual ~InternalState() {}
private:
- Section(const char* sectionName, const char* segmentName, bool zeroFill, bool untrustedZeroFill);
+ bool inMoveRWChain(const ld::Atom& atom, const char* filePath, const char*& dstSeg, bool& wildCardMatch);
+ bool inMoveROChain(const ld::Atom& atom, const char* filePath, const char*& dstSeg, bool& wildCardMatch);
- 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, 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 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;
+
+ 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;
+ static ld::Section _s_DATA_DIRTY_data;
+ static ld::Section _s_DATA_CONST_const;
+ };
+
+ bool hasZeroForFileOffset(const ld::Section* sect);
+ uint64_t pageAlign(uint64_t addr);
+ uint64_t pageAlign(uint64_t addr, uint64_t pageSize);
+
+ struct SectionHash {
+ size_t operator()(const ld::Section*) const;
+ };
+ struct SectionEquals {
+ bool operator()(const ld::Section* left, const ld::Section* right) const;
};
+ typedef std::unordered_map<const ld::Section*, FinalSection*, SectionHash, SectionEquals> SectionInToOut;
+
- 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;
+ SectionInToOut _sectionInToFinalMap;
+ const Options& _options;
+ bool _atomsOrderedInSections;
+ std::unordered_map<const ld::Atom*, const char*> _pendingSegMove;
+};
- char fSectionName[18];
- char fSegmentName[18];
- bool fZeroFill;
- bool fUntrustedZeroFill;
+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);
+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);
- static NameToSection fgMapping;
- static std::vector<Section*> fgSections;
- static NameToOrdinal fgSegmentDiscoverOrder;
- static bool fgMakingObjectFile;
-};
+std::vector<const char*> InternalState::FinalSection::_s_segmentsSeen;
-Section::NameToSection Section::fgMapping;
-std::vector<Section*> Section::fgSections;
-Section::NameToOrdinal Section::fgSegmentDiscoverOrder;
-bool Section::fgMakingObjectFile;
-Section::Section(const char* sectionName, const char* segmentName, bool zeroFill, bool untrustedZeroFill)
- : fZeroFill(zeroFill), fUntrustedZeroFill(untrustedZeroFill)
+size_t InternalState::SectionHash::operator()(const ld::Section* sect) const
{
- 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 mach header and load commands to start of TEXT
- if ( strcmp(sectionName, "._mach_header") == 0 )
- this->fIndex = 1;
- else if ( strcmp(sectionName, "._load_commands") == 0 )
- this->fIndex = 2;
- else if ( strcmp(sectionName, "._load_cmds_pad") == 0 )
- this->fIndex = 3;
- // sort __text after load commands
- else if ( strcmp(sectionName, "__text") == 0 )
- this->fIndex = 10;
- // sort arm/ppc stubs after text to make branch islands feasible
- else if ( strcmp(sectionName, "__picsymbolstub4") == 0 )
- this->fIndex = 11;
- else if ( strcmp(sectionName, "__symbol_stub4") == 0 )
- this->fIndex = 11;
- else if ( strcmp(sectionName, "__picsymbolstub1") == 0 )
- this->fIndex = 11;
- else if ( strcmp(sectionName, "__symbol_stub1") == 0 )
- this->fIndex = 11;
- // sort fast arm stubs to end of __TEXT to be close to lazy pointers
- else if ( strcmp(sectionName, "__symbolstub1") == 0 )
- this->fIndex = INT_MAX;
- // sort unwind info to end of segment
- else if ( strcmp(sectionName, "__eh_frame") == 0 )
- this->fIndex = INT_MAX-1;
- else if ( strcmp(sectionName, "__unwind_info") == 0 )
- this->fIndex = INT_MAX-2;
- else if ( strcmp(sectionName, "__gcc_except_tab") == 0 )
- this->fIndex = INT_MAX-3;
- }
- else if ( strcmp(segmentName, "__DATA") == 0 ) {
- // sort arm lazy symbol pointers that must be at start of __DATA
- if ( strcmp(sectionName, "__lazy_symbol") == 0 )
- this->fIndex = 0;
- // sort sections dyld will touch to start of segment
- else 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;
- else if ( strcmp(sectionName, "__huge") == 0 )
- this->fIndex = INT_MAX;
-
- }
-
- //fprintf(stderr, "new Section(%s, %s) => %p, %u\n", sectionName, segmentName, this, this->getIndex());
+ size_t hash = 0;
+ ld::CStringHash temp;
+ hash += temp.operator()(sect->segmentName());
+ hash += temp.operator()(sect->sectionName());
+ return hash;
}
-Section* Section::find(const char* sectionName, const char* segmentName, bool zeroFill, bool untrustedZeroFill, bool createIfNeeded)
+bool InternalState::SectionEquals::operator()(const ld::Section* left, const ld::Section* right) const
{
- NameToSection::iterator pos = fgMapping.find(sectionName);
- if ( pos != fgMapping.end() ) {
- if ( strcmp(pos->second->fSegmentName, segmentName) == 0 ) {
- if ( !untrustedZeroFill && pos->second->fUntrustedZeroFill ) {
- pos->second->fZeroFill = zeroFill;
- pos->second->fUntrustedZeroFill = false;
- }
- 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;
- }
- }
+ return (*left == *right);
+}
- if ( !createIfNeeded )
- return NULL;
-
- // does not exist, so make a new one
- Section* sect = new Section(sectionName, segmentName, zeroFill, untrustedZeroFill);
- 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, true);
- }
+InternalState::FinalSection::FinalSection(const ld::Section& sect, uint32_t sectionsSeen, const Options& opts)
+ : ld::Internal::FinalSection(sect),
+ _segmentOrder(segmentOrder(sect, opts)),
+ _sectionOrder(sectionOrder(sect, sectionsSeen, opts))
+{
+ //fprintf(stderr, "FinalSection(%16s, %16s) _segmentOrder=%3d, _sectionOrder=0x%08X\n",
+ // this->segmentName(), this->sectionName(), _segmentOrder, _sectionOrder);
+}
- // remember segment discovery order
- if ( fgSegmentDiscoverOrder.find(segmentName) == fgSegmentDiscoverOrder.end() )
- fgSegmentDiscoverOrder[segmentName] = fgSegmentDiscoverOrder.size();
+const ld::Section& InternalState::FinalSection::outputSection(const ld::Section& sect, bool mergeZeroFill)
+{
+ // merge sections in final linked image
+ switch ( sect.type() ) {
+ case ld::Section::typeLiteral4:
+ case ld::Section::typeLiteral8:
+ case ld::Section::typeLiteral16:
+ 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 )
+ 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;
+ }
+ 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 )
+ return _s_DATA_zerofill;
+ break;
+ 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 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 ld::Section::typeTentativeDefs:
+ 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;
+ }
+ return sect;
+}
+const ld::Section& InternalState::FinalSection::objectOutputSection(const ld::Section& sect, const Options& options)
+{
+ // 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;
}
-int Section::Sorter::segmentOrdinal(const char* segName)
+uint32_t InternalState::FinalSection::segmentOrder(const ld::Section& sect, const Options& options)
{
- if ( strcmp(segName, "__HEADER") == 0 )
- return 1;
- if ( strcmp(segName, "__PAGEZERO") == 0 )
+ 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 ( options.outputKind() == Options::kStaticExecutable ) {
+ 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(), "__PAGEZERO") == 0 )
+ return 0;
+ 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;
+ if ( strcmp(sect.segmentName(), "__TEXT_EXEC") == 0 )
+ return 2;
+ // in -r mode, want __DATA last so zerofill sections are at end
+ if ( strcmp(sect.segmentName(), "__DATA") == 0 )
+ return (options.outputKind() == Options::kObjectFile) ? 6 : 3;
+ if ( strcmp(sect.segmentName(), "__OBJC") == 0 )
+ return 4;
+ if ( strcmp(sect.segmentName(), "__IMPORT") == 0 )
+ return 5;
+ }
+ // 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 )
+ return i+100;
+ }
+ _s_segmentsSeen.push_back(sect.segmentName());
+ return _s_segmentsSeen.size()-1+100;
+}
+
+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::typeMachHeader )
return 1;
- if ( strcmp(segName, "__TEXT") == 0 )
- return 2;
- if ( strcmp(segName, "__DATA") == 0 )
- return (fgMakingObjectFile ? 6 : 3); // __DATA is last in .o files and here in FLI
- if ( strcmp(segName, "__OBJC") == 0 )
- return 4;
- if ( strcmp(segName, "__IMPORT") == 0 )
- return 5;
- if ( strcmp(segName, "__LINKEDIT") == 0 )
- return INT_MAX; // linkedit segment should always sort last
- else
- return fgSegmentDiscoverOrder[segName]+6;
+ 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:
+ // <rdar://problem/8346444> make __text always be first "code" section
+ if ( strcmp(sect.sectionName(), "__text") == 0 )
+ return 10;
+ else
+ return 11;
+ case ld::Section::typeNonStdCString:
+ if ( (strcmp(sect.sectionName(), "__oslogstring") == 0) && options.makeEncryptable() )
+ return INT_MAX-1;
+ else
+ return sectionsSeen+20;
+ case ld::Section::typeStub:
+ return 12;
+ case ld::Section::typeStubHelper:
+ return 13;
+ case ld::Section::typeLSDA:
+ return INT_MAX-4;
+ case ld::Section::typeUnwindInfo:
+ return INT_MAX-3;
+ case ld::Section::typeCFI:
+ return INT_MAX-2;
+ case ld::Section::typeStubClose:
+ return INT_MAX;
+ default:
+ return sectionsSeen+20;
+ }
+ }
+ else if ( strncmp(sect.segmentName(), "__DATA", 6) == 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-259; // need TLV zero-fill to follow TLV init values
+ case ld::Section::typeTLVZeroFill:
+ return INT_MAX-258;
+ 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-256+sectionsSeen; // <rdar://problem/25448494> zero fill need to be last and in "seen" order
+ default:
+ // <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;
+ 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_nlcatlist") == 0 )
+ return 23;
+ else if ( strcmp(sect.sectionName(), "__objc_protolist") == 0 )
+ return 24;
+ else if ( strcmp(sect.sectionName(), "__objc_imageinfo") == 0 )
+ return 25;
+ else if ( strcmp(sect.sectionName(), "__objc_const") == 0 )
+ return 26;
+ else if ( strcmp(sect.sectionName(), "__objc_selrefs") == 0 )
+ return 27;
+ else if ( strcmp(sect.sectionName(), "__objc_msgrefs") == 0 )
+ return 28;
+ else if ( strcmp(sect.sectionName(), "__objc_protorefs") == 0 )
+ return 29;
+ else if ( strcmp(sect.sectionName(), "__objc_classrefs") == 0 )
+ return 30;
+ else if ( strcmp(sect.sectionName(), "__objc_superrefs") == 0 )
+ 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;
+ }
+ }
+ // make sure zerofill in any other section is at end of segment
+ if ( sect.type() == ld::Section::typeZeroFill )
+ return INT_MAX-256+sectionsSeen;
+ 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);
+ }
+ }
+ 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
+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;
+}
-bool Section::Sorter::operator()(Section* left, Section* right)
+bool InternalState::inMoveRWChain(const ld::Atom& atom, const char* filePath, const char*& dstSeg, bool& wildCardMatch)
{
- // Segment is primary sort key
- int leftSegOrdinal = segmentOrdinal(left->fSegmentName);
- int rightSegOrdinal = segmentOrdinal(right->fSegmentName);
- if ( leftSegOrdinal < rightSegOrdinal )
- return true;
- if ( leftSegOrdinal > rightSegOrdinal )
+ if ( !_options.hasDataSymbolMoves() )
return false;
- // zerofill section sort to the end
- if ( !left->fZeroFill && right->fZeroFill )
+ auto pos = _pendingSegMove.find(&atom);
+ if ( pos != _pendingSegMove.end() ) {
+ dstSeg = pos->second;
return true;
- if ( left->fZeroFill && !right->fZeroFill )
- return false;
-
- // section discovery order is last sort key
- return left->fIndex < right->fIndex;
-}
+ }
-void Section::assignIndexes(bool objfile)
-{
- //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);
- //}
+ bool result = false;
+ if ( _options.moveRwSymbol(atom.name(), filePath, dstSeg, wildCardMatch) )
+ result = true;
- // sort it
- Section::fgMakingObjectFile = objfile;
- std::sort(fgSections.begin(), fgSections.end(), Section::Sorter());
+ for (ld::Fixup::iterator fit=atom.fixupsBegin(); fit != atom.fixupsEnd(); ++fit) {
+ if ( fit->kind == ld::Fixup::kindNoneFollowOn ) {
+ if ( fit->binding == ld::Fixup::bindingDirectlyBound ) {
+ if ( inMoveRWChain(*(fit->u.target), filePath, dstSeg, wildCardMatch) )
+ result = true;
+ }
+ }
+ }
- // 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++;
+ if ( result ) {
+ for (ld::Fixup::iterator fit=atom.fixupsBegin(); fit != atom.fixupsEnd(); ++fit) {
+ if ( fit->kind == ld::Fixup::kindNoneFollowOn ) {
+ if ( fit->binding == ld::Fixup::bindingDirectlyBound ) {
+ _pendingSegMove[fit->u.target] = dstSeg;
+ }
+ }
+ }
+ }
- //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);
- //}
+ return result;
}
-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&);
- const char* fileArch(const void* p);
- 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 addSynthesizedAtoms();
- 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, bool searchArchives=false);
- 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);
+bool InternalState::inMoveROChain(const ld::Atom& atom, const char* filePath, const char*& dstSeg, bool& wildCardMatch)
+{
+ if ( !_options.hasCodeSymbolMoves() )
+ return false;
- 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);
+ auto pos = _pendingSegMove.find(&atom);
+ if ( pos != _pendingSegMove.end() ) {
+ dstSeg = pos->second;
+ return true;
+ }
- void logTraceInfo(const char* format, ...);
+ bool result = false;
+ if ( _options.moveRoSymbol(atom.name(), filePath, dstSeg, wildCardMatch) )
+ result = true;
+ for (ld::Fixup::iterator fit=atom.fixupsBegin(); fit != atom.fixupsEnd(); ++fit) {
+ if ( fit->kind == ld::Fixup::kindNoneFollowOn ) {
+ if ( fit->binding == ld::Fixup::bindingDirectlyBound ) {
+ if ( inMoveROChain(*(fit->u.target), filePath, dstSeg, wildCardMatch) )
+ result = true;
+ }
+ }
+ }
- class SymbolTable
- {
- public:
- typedef __gnu_cxx::hash_map<const char*, ObjectFile::Atom*, __gnu_cxx::hash<const char*>, CStringEquals> Mapper;
+ if ( result ) {
+ for (ld::Fixup::iterator fit=atom.fixupsBegin(); fit != atom.fixupsEnd(); ++fit) {
+ if ( fit->kind == ld::Fixup::kindNoneFollowOn ) {
+ if ( fit->binding == ld::Fixup::bindingDirectlyBound ) {
+ _pendingSegMove[fit->u.target] = dstSeg;
+ }
+ }
+ }
+ }
- SymbolTable(Linker&);
- void require(const char* name);
- bool add(ObjectFile::Atom& atom);
- ObjectFile::Atom* find(const char* name);
- void erase(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; }
- uint32_t dylibSymbolCount() { return fDylibSymbolCount; }
- Mapper::iterator begin() { return fTable.begin(); }
- Mapper::iterator end() { return fTable.end(); }
+ return result;
+}
- private:
- Linker& fOwner;
- Mapper fTable;
- unsigned int fRequireCount;
- bool fHasExternalTentativeDefinitions;
- bool fHasExternalWeakDefinitions;
- uint32_t fDylibSymbolCount;
- };
- 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;
+ld::Internal::FinalSection* InternalState::addAtom(const ld::Atom& atom)
+{
+ //fprintf(stderr, "addAtom: %s\n", atom.name());
+ ld::Internal::FinalSection* fs = NULL;
+ const char* curSectName = atom.section().sectionName();
+ const char* curSegName = atom.section().segmentName();
+ 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() )
+ curSectName = FinalSection::_s_DATA_zerofill.sectionName();
+ else
+ curSectName = FinalSection::_s_DATA_common.sectionName();
+ }
+ // Support for -move_to_r._segment
+ if ( atom.symbolTableInclusion() == ld::Atom::symbolTableIn ) {
+ const char* dstSeg;
+ bool wildCardMatch;
+ if ( inMoveRWChain(atom, 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 {
+ curSegName = dstSeg;
+ if ( _options.traceSymbolLayout() )
+ printf("symbol '%s', -move_to_rw_segment mapped it to %s/%s\n", atom.name(), curSegName, curSectName);
+ fs = this->getFinalSection(curSegName, curSectName, sectType);
+ }
+ }
+ if ( (fs == NULL) && inMoveROChain(atom, 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 {
+ curSegName = dstSeg;
+ if ( _options.traceSymbolLayout() )
+ printf("symbol '%s', -move_to_ro_segment mapped it to %s/%s\n", atom.name(), curSegName, curSectName);
+ fs = this->getFinalSection(curSegName, curSectName, ld::Section::typeCode);
+ }
+ }
+ }
+ // support for -rename_section and -rename_segment
+ for (const Options::SectionRename& rename : _options.sectionRenames()) {
+ if ( (strcmp(curSectName, rename.fromSection) == 0) && (strcmp(curSegName, rename.fromSegment) == 0) ) {
+ if ( _options.useDataConstSegment() && (strcmp(curSectName, "__const") == 0) && (strcmp(curSegName, "__DATA") == 0) && hasReferenceToWeakExternal(atom) ) {
+ // if __DATA,__const atom has pointer to weak external symbol, don't move to __DATA_CONST
+ curSectName = "__const_weak";
+ fs = this->getFinalSection(curSegName, curSectName, 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
+ curSectName = "__got_weak";
+ fs = this->getFinalSection("__DATA", curSectName, sectType);
+ if ( _options.traceSymbolLayout() )
+ printf("symbol '%s', contains pointers to weak symbols, so mapped it to __DATA/__got_weak\n", atom.name());
+ }
+ else {
+ curSegName = rename.toSegment;
+ curSectName = rename.toSection;
+ fs = this->getFinalSection(rename.toSegment, rename.toSection, sectType);
+ if ( _options.traceSymbolLayout() )
+ printf("symbol '%s', -rename_section mapped it to %s/%s\n", atom.name(), fs->segmentName(), fs->sectionName());
+ }
+ }
+ }
+ for (const Options::SegmentRename& rename : _options.segmentRenames()) {
+ if ( strcmp(curSegName, rename.fromSegment) == 0 ) {
+ if ( _options.traceSymbolLayout() )
+ printf("symbol '%s', -rename_segment mapped it to %s/%s\n", atom.name(), rename.toSegment, curSectName);
+ fs = this->getFinalSection(rename.toSegment, curSectName, sectType);
+ }
+ }
- struct IndirectLibrary {
- const char* path;
- uint64_t fileLen;
- ObjectFile::Reader* reader;
- std::set<ObjectFile::Reader*> parents;
- ObjectFile::Reader* reExportedViaDirectLibrary;
- };
+ // 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());
+ }
- ObjectFile::Reader* findDirectLibraryWhichReExports(struct IndirectLibrary& indirectLib);
+ //fprintf(stderr, "InternalState::doAtom(%p), name=%s, sect=%s, finalseg=%s\n", &atom, atom.name(), atom.section().sectionName(), fs->segmentName());
+#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 {
+ // not end atom, just append new atom
+ fs->atoms.push_back(&atom);
+ }
+ }
+ else {
+ // normal case
+ fs->atoms.push_back(&atom);
+ }
+ this->atomToSection[&atom] = fs;
+ return fs;
+}
- 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)
-{
- fStartTime = mach_absolute_time();
- if ( fOptions.printStatistics() )
- getVMInfo(fStartVMInfo);
+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));
+}
- fArchitecture = fOptions.architecture();
- if ( fArchitecture == 0 ) {
- // -arch not specified, scan .o files to figure out what it should be
- fArchitecture = inferArchitecture();
- fArchitectureInferred = true;
+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;
}
- switch (fArchitecture) {
- case CPU_TYPE_POWERPC:
- fArchitectureName = "ppc";
- break;
- case CPU_TYPE_POWERPC64:
- fArchitectureName = "ppc64";
- break;
- case CPU_TYPE_I386:
- fArchitectureName = "i386";
- break;
- case CPU_TYPE_X86_64:
- fArchitectureName = "x86_64";
- break;
- case CPU_TYPE_ARM:
- fArchitectureName = "arm";
- if ( fOptions.preferSubArchitecture() ) {
- switch ( fOptions.subArchitecture() ) {
- case CPU_SUBTYPE_ARM_V4T:
- fArchitectureName = "armv4t";
- break;
- case CPU_SUBTYPE_ARM_V5TEJ:
- fArchitectureName = "armv5";
- break;
- case CPU_SUBTYPE_ARM_V6:
- fArchitectureName = "armv6";
- break;
- case CPU_SUBTYPE_ARM_V7:
- fArchitectureName = "armv7";
- break;
+
+ // otherwise, create a new final section
+ 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 ( outSect != inputSection ) {
+ // new output section created, but not in map
+ baseForFinalSection = &outSect;
}
}
break;
- default:
- fArchitectureName = "unknown architecture";
+ case Options::kObjectFile:
+ baseForFinalSection = &FinalSection::objectOutputSection(inputSection, _options);
+ pos = _sectionInToFinalMap.find(baseForFinalSection);
+ if ( pos != _sectionInToFinalMap.end() ) {
+ _sectionInToFinalMap[&inputSection] = pos->second;
+ //fprintf(stderr, "_sectionInToFinalMap[%p] = %p\n", &inputSection, pos->second);
+ return pos->second;
+ }
break;
}
-}
-const char* Linker::architectureName()
-{
- return fArchitectureName;
+ InternalState::FinalSection* result = new InternalState::FinalSection(*baseForFinalSection,
+ _sectionInToFinalMap.size(), _options);
+ _sectionInToFinalMap[baseForFinalSection] = result;
+ //fprintf(stderr, "_sectionInToFinalMap[%p(%s)] = %p\n", baseForFinalSection, baseForFinalSection->sectionName(), result);
+ sections.push_back(result);
+ return result;
}
-bool Linker::showArchitectureInErrors()
+
+int InternalState::FinalSection::sectionComparer(const void* l, const void* r)
{
- return fOptions.printArchPrefix();
+ 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);
}
-bool Linker::isInferredArchitecture()
+void InternalState::sortSections()
{
- return fArchitectureInferred;
+ //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(§ions[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)) );
+
}
-cpu_type_t Linker::inferArchitecture()
+
+bool InternalState::hasZeroForFileOffset(const ld::Section* sect)
{
- // 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;
- }
- }
- }
+ switch ( sect->type() ) {
+ case ld::Section::typeZeroFill:
+ case ld::Section::typeTLVZeroFill:
+ return _options.optimizeZeroFill();
+ case ld::Section::typePageZero:
+ case ld::Section::typeStack:
+ case ld::Section::typeTentativeDefs:
+ return true;
+ default:
+ break;
}
-
- // 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
+ return false;
}
-
-void Linker::addInputFile(ObjectFile::Reader* reader, const Options::FileInfo& info)
+uint64_t InternalState::pageAlign(uint64_t addr)
{
- fInputFiles.push_back(reader);
- fDylibOptionsMap[reader] = info.options;
+ const uint64_t alignment = _options.segmentAlignment();
+ return ((addr+alignment-1) & (-alignment));
}
-void Linker::setOutputFile(ExecutableFile::Writer* writer)
+uint64_t InternalState::pageAlign(uint64_t addr, uint64_t pageSize)
{
- fOutputFile = writer;
+ return ((addr+pageSize-1) & (-pageSize));
}
-class InSet
+void InternalState::setSectionSizesAndAlignments()
{
-public:
- InSet(std::set<ObjectFile::Atom*>& deadAtoms) : fDeadAtoms(deadAtoms) {}
-
- bool operator()(ObjectFile::Atom*& atom) const {
- return ( fDeadAtoms.count(atom) != 0 );
+ for (std::vector<ld::Internal::FinalSection*>::iterator sit = sections.begin(); sit != sections.end(); ++sit) {
+ ld::Internal::FinalSection* sect = *sit;
+ if ( sect->type() == ld::Section::typeAbsoluteSymbols ) {
+ // absolute symbols need their finalAddress() to their value
+ for (std::vector<const ld::Atom*>::iterator ait = sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
+ const ld::Atom* atom = *ait;
+ (const_cast<ld::Atom*>(atom))->setSectionOffset(atom->objectAddress());
+ }
+ }
+ else {
+ uint16_t maxAlignment = 0;
+ uint64_t offset = 0;
+ for (std::vector<const ld::Atom*>::iterator ait = sect->atoms.begin(); ait != sect->atoms.end(); ++ait) {
+ const ld::Atom* atom = *ait;
+ bool pagePerAtom = false;
+ uint32_t atomAlignmentPowerOf2 = atom->alignment().powerOf2;
+ uint32_t atomModulus = atom->alignment().modulus;
+ 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 )
+ contiguousObjCSection = false;
+ if ( strcmp(atom->section().sectionName(), "__objc_data") == 0 )
+ contiguousObjCSection = false;
+ switch ( atom->section().type() ) {
+ case ld::Section::typeUnclassified:
+ case ld::Section::typeTentativeDefs:
+ case ld::Section::typeZeroFill:
+ if ( contiguousObjCSection )
+ break;
+ pagePerAtom = true;
+ if ( atomAlignmentPowerOf2 < 12 ) {
+ atomAlignmentPowerOf2 = 12;
+ atomModulus = 0;
+ }
+ break;
+ default:
+ break;
+ }
+ }
+ if ( atomAlignmentPowerOf2 > maxAlignment )
+ maxAlignment = atomAlignmentPowerOf2;
+ // calculate section offset for this atom
+ uint64_t alignment = 1 << atomAlignmentPowerOf2;
+ uint64_t currentModulus = (offset % alignment);
+ uint64_t requiredModulus = atomModulus;
+ if ( currentModulus != requiredModulus ) {
+ if ( requiredModulus > currentModulus )
+ offset += requiredModulus-currentModulus;
+ else
+ offset += requiredModulus+alignment-currentModulus;
+ }
+ // LINKEDIT atoms are laid out later
+ if ( sect->type() != ld::Section::typeLinkEdit ) {
+ (const_cast<ld::Atom*>(atom))->setSectionOffset(offset);
+ offset += atom->size();
+ if ( pagePerAtom ) {
+ offset = (offset + 4095) & (-4096); // round up to end of page
+ }
+ }
+ if ( (atom->scope() == ld::Atom::scopeGlobal)
+ && (atom->definition() == ld::Atom::definitionRegular)
+ && (atom->combine() == ld::Atom::combineByName)
+ && ((atom->symbolTableInclusion() == ld::Atom::symbolTableIn)
+ || (atom->symbolTableInclusion() == ld::Atom::symbolTableInAndNeverStrip)) ) {
+ this->hasWeakExternalSymbols = true;
+ if ( _options.warnWeakExports() )
+ warning("weak external symbol: %s", atom->name());
+ }
+ }
+ sect->size = offset;
+ // section alignment is that of a contained atom with the greatest alignment
+ sect->alignment = maxAlignment;
+ // unless -sectalign command line option overrides
+ if ( _options.hasCustomSectionAlignment(sect->segmentName(), sect->sectionName()) )
+ sect->alignment = _options.customSectionAlignment(sect->segmentName(), sect->sectionName());
+ // each atom in __eh_frame has zero alignment to assure they pack together,
+ // but compilers usually make the CFIs pointer sized, so we want whole section
+ // to start on pointer sized boundary.
+ if ( sect->type() == ld::Section::typeCFI )
+ sect->alignment = 3;
+ if ( sect->type() == ld::Section::typeTLVDefs )
+ this->hasThreadLocalVariableDefinitions = true;
+ }
}
-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());
+ // <rdar://problem/24221680> All __thread_data and __thread_bss sections must have same alignment
+ uint8_t maxThreadAlign = 0;
+ for (ld::Internal::FinalSection* sect : sections) {
+ if ( (sect->type() == ld::Section::typeTLVInitialValues) || (sect->type() == ld::Section::typeTLVZeroFill) ) {
+ if ( sect->alignment > maxThreadAlign )
+ maxThreadAlign = sect->alignment;
+ }
}
- else {
- // with dead code stripping:
- // start binding references from roots,
- this->deadStripResolve();
- // verify nothing is missing
- this->checkUndefines();
+ for (ld::Internal::FinalSection* sect : sections) {
+ if ( (sect->type() == ld::Section::typeTLVInitialValues) || (sect->type() == ld::Section::typeTLVZeroFill) ) {
+ sect->alignment = maxThreadAlign;
+ }
}
-}
-
-void Linker::addSynthesizedAtoms()
-{
- // give write a chance to synthesize stub, GOT, and lazy pointer atoms
- std::vector<class ObjectFile::Atom*> newAtoms;
- fOutputFile->addSynthesizedAtoms(fAllAtoms, this->dyldClassicHelper(),
- this->dyldCompressedHelper(), this->dyldLazyLibraryHelper(),
- fBiggerThanTwoGigOutput,
- fGlobalSymbolTable.dylibSymbolCount(),
- newAtoms);
- // add all newly created atoms to fAllAtoms and update symbol table
- this->addAtoms(newAtoms);
}
-void Linker::optimize()
+uint64_t InternalState::assignFileOffsets()
{
- // 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());
- }
+ const bool log = false;
+ const bool hiddenSectionsOccupyAddressSpace = ((_options.outputKind() != Options::kObjectFile)
+ && (_options.outputKind() != Options::kPreload));
+ const bool segmentsArePageAligned = (_options.outputKind() != Options::kObjectFile);
+
+ uint64_t address = 0;
+ const char* lastSegName = "";
+ uint64_t floatingAddressStart = _options.baseAddress();
+ bool haveFixedSegments = false;
- // only do next steps if some optimization was actually done
- if ( didSomething ) {
+ // 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;
+ haveFixedSegments = true;
+ if ( segmentsArePageAligned ) {
+ if ( strcmp(lastSegName, sect->segmentName()) != 0 ) {
+ address = _options.customSegmentAddress(sect->segmentName());
+ lastSegName = sect->segmentName();
+ }
+ }
+ // adjust section address based on alignment
+ uint64_t unalignedAddress = address;
+ uint64_t alignment = (1 << sect->alignment);
+ address = ( (unalignedAddress+alignment-1) & (-alignment) );
- if ( fOptions.deadStrip() != Options::kDeadStripOff ) {
- for(std::vector<class ObjectFile::Atom*>::iterator itr = newAtoms.begin(); itr != newAtoms.end(); ++itr) {
- ObjectFile::Atom* atom = *itr;
- const char* name = atom->getName();
- if ( name != NULL ) {
- ObjectFile::Atom* existingAtom = fGlobalSymbolTable.find(name);
- if ( (existingAtom != NULL) && fLiveAtoms.count(existingAtom) == 0 ) {
- // While dead code stripping, the atoms were not removed from fGlobalSymbolTable
- // for performance reasons. Normally, libLTO will never recreate an atom
- // that was previously dead stripped away, but if it does remove
- // the remnents of the previous so the new one can be added
- fGlobalSymbolTable.erase(name);
- }
- }
- }
- }
-
- // 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(), true));
- }
-
- // 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);
+ // update section info
+ sect->address = address;
+ sect->alignmentPaddingBytes = (address - unalignedAddress);
+
+ // sanity check size
+ if ( ((address + sect->size) > _options.maxAddress()) && (_options.outputKind() != Options::kObjectFile)
+ && (_options.outputKind() != Options::kStaticExecutable) )
+ throwf("section %s (address=0x%08llX, size=%llu) would make the output executable exceed available address range",
+ sect->sectionName(), address, sect->size);
+
+ 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;
+
+ // if TEXT segment address is fixed, then flow other segments after it
+ if ( strcmp(sect->segmentName(), "__TEXT") == 0 ) {
+ floatingAddressStart = address;
+ }
+ }
+
+ // 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;
+ ld::Internal::FinalSection* overlappingFlowSection = NULL;
+ ld::Internal::FinalSection* prevSect = NULL;
+ 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 ( sect->address != ULLONG_MAX )
+ continue;
+ if ( (_options.outputKind() == Options::kPreload) && (sect->type() == ld::Section::typeMachHeader) ) {
+ sect->alignmentPaddingBytes = 0;
+ continue;
+ }
+ if ( segmentsArePageAligned ) {
+ if ( strcmp(lastSegName, sect->segmentName()) != 0 ) {
+ // round up size of last segment if needed
+ if ( *lastSegName != '\0' ) {
+ address = pageAlign(address, _options.segPageSize(lastSegName));
+ }
+ // set segment address based on end of last segment
+ address = pageAlign(address);
+ lastSegName = sect->segmentName();
}
}
- if ( fOptions.deadStrip() != Options::kDeadStripOff ) {
- // LTO may optimize away some atoms, so dead stripping must be redone
- fLiveAtoms.clear();
- this->deadStripResolve();
- this->checkUndefines();
- }
- else {
- // LTO may require new library symbols to be loaded, so redo
- this->checkUndefines();
- this->resolveReferences();
- }
- }
-}
-
-
-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 ) {
- if ( atom->getSymbolTableInclusion() == ObjectFile::Atom::kSymbolTableIn ) {
- // we do have an exported weak symbol, turn WEAK_DEFINES back on
- fGlobalSymbolTable.setHasExternalWeakDefinitions(true);
- }
- }
+ // adjust section address based on alignment
+ uint64_t unalignedAddress = address;
+ uint64_t alignment = (1 << sect->alignment);
+ address = ( (unalignedAddress+alignment-1) & (-alignment) );
+
+ // update section info
+ sect->address = address;
+ sect->alignmentPaddingBytes = (address - unalignedAddress);
+
+ // <rdar://problem/21994854> if first section is more aligned than segment, move segment start up to match
+ if ( (prevSect != NULL) && (prevSect->type() == ld::Section::typeFirstSection) && (strcmp(prevSect->segmentName(), sect->segmentName()) == 0) ) {
+ assert(prevSect->size == 0);
+ if ( prevSect->address != sect->address ) {
+ prevSect->alignmentPaddingBytes += (sect->address - prevSect->address);
+ prevSect->address = sect->address;
+ }
+ }
+
+ // sanity check size
+ if ( ((address + sect->size) > _options.maxAddress()) && (_options.outputKind() != Options::kObjectFile)
+ && (_options.outputKind() != Options::kStaticExecutable) )
+ throwf("section %s (address=0x%08llX, size=%llu) would make the output executable exceed available address range",
+ sect->sectionName(), address, sect->size);
+
+ // sanity check it does not overlap a fixed address segment
+ for (std::vector<ld::Internal::FinalSection*>::iterator sit = sections.begin(); sit != sections.end(); ++sit) {
+ 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;
+ overlappingFlowSection = sect;
}
- 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 ( (sect->address+sect->size) > otherSect->address ) {
+ overlappingFixedSection = otherSect;
+ overlappingFlowSection = sect;
}
}
}
+
+ if ( log ) fprintf(stderr, " address=0x%08llX, size=0x%08llX, hidden=%d, alignment=%02d, padBytes=%d, section=%s,%s\n",
+ sect->address, sect->size, sect->isSectionHidden(), sect->alignment, sect->alignmentPaddingBytes,
+ sect->segmentName(), sect->sectionName());
+ // update running totals
+ if ( !sect->isSectionHidden() || hiddenSectionsOccupyAddressSpace )
+ address += sect->size;
+ prevSect = sect;
+ }
+ if ( overlappingFixedSection != NULL ) {
+ 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;
+ 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());
+
+ }
+ throwf("Section (%s/%s) overlaps fixed address section (%s/%s)",
+ overlappingFlowSection->segmentName(), overlappingFlowSection->sectionName(),
+ overlappingFixedSection->segmentName(), overlappingFixedSection->sectionName());
}
- // 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
+
+ // third pass, assign section file offsets
+ uint64_t fileOffset = 0;
+ lastSegName = "";
+ if ( log ) fprintf(stderr, "All segments with file offsets:\n");
+ for (std::vector<ld::Internal::FinalSection*>::iterator it = sections.begin(); it != sections.end(); ++it) {
+ ld::Internal::FinalSection* sect = *it;
+ if ( hasZeroForFileOffset(sect) ) {
+ // fileoff of zerofill sections is moot, but historically it is set to zero
+ sect->fileOffset = 0;
+
+ // <rdar://problem/10445047> align file offset with address layout
+ fileOffset += sect->alignmentPaddingBytes;
+ }
+ else {
+ // page align file offset at start of each segment
+ if ( segmentsArePageAligned && (*lastSegName != '\0') && (strcmp(lastSegName, sect->segmentName()) != 0) ) {
+ fileOffset = pageAlign(fileOffset, _options.segPageSize(lastSegName));
+ }
+ lastSegName = sect->segmentName();
+
+ // align file offset with address layout
+ fileOffset += sect->alignmentPaddingBytes;
+
+ // update section info
+ sect->fileOffset = fileOffset;
+
+ // update running total
+ fileOffset += sect->size;
+ }
+
+ if ( log ) fprintf(stderr, " fileoffset=0x%08llX, address=0x%08llX, hidden=%d, size=%lld, alignment=%02d, section=%s,%s\n",
+ sect->fileOffset, sect->address, sect->isSectionHidden(), sect->size, sect->alignment,
+ sect->segmentName(), sect->sectionName());
}
- 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());
+
+#if 0
+ // for encrypted iPhoneOS apps
+ if ( _options.makeEncryptable() ) {
+ // remember end of __TEXT for later use by load command
+ for (std::vector<ld::Internal::FinalSection*>::iterator it = state.sections.begin(); it != state.sections.end(); ++it) {
+ ld::Internal::FinalSection* sect = *it;
+ if ( strcmp(sect->segmentName(), "__TEXT") == 0 ) {
+ _encryptedTEXTendOffset = pageAlign(sect->fileOffset + sect->size);
}
}
}
+#endif
+
+ // return total file size
+ return fileOffset;
}
-void Linker::link()
+static char* commatize(uint64_t in, char* out)
{
- this->buildAtomList();
- this->loadAndResolve();
- this->optimize();
- this->adjustScope();
- this->checkObjC();
- this->processDTrace();
- this->tweakLayout();
- this->addSynthesizedAtoms();
- this->sortSections();
- this->sortAtoms();
- this->writeDotOutput();
- this->collectDebugInfo();
- this->writeOutput();
- this->printStatistics();
-
- if ( fOptions.pauseAtEnd() )
- sleep(10);
+ 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 ) {
struct mach_timebase_info timeBaseInfo;
- if ( mach_timebase_info(&timeBaseInfo) == KERN_SUCCESS ) {
- sUnitsPerSecond = 1000000000ULL * timeBaseInfo.denom / timeBaseInfo.numer;
- //fprintf(stderr, "sUnitsPerSecond=%llu\n", sUnitsPerSecond);
- }
+ if ( mach_timebase_info(&timeBaseInfo) != KERN_SUCCESS )
+ return;
+ sUnitsPerSecond = 1000000000ULL * timeBaseInfo.denom / timeBaseInfo.numer;
}
if ( partTime < sUnitsPerSecond ) {
uint32_t milliSecondsTimeTen = (partTime*10000)/sUnitsPerSecond;
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,
}
}
-void Linker::printStatistics()
-{
- 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));
- }
-}
-
-inline void Linker::addAtom(ObjectFile::Atom& atom)
-{
- // add to list of all atoms
- fAllAtoms.push_back(&atom);
-
- 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());
- }
- // 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);
- }
-
- // 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()) {
- bool untrusted = false;
- switch ( atom.getContentType() ) {
- case ObjectFile::Atom::kSectionStart:
- case ObjectFile::Atom::kSectionEnd:
- untrusted = true;
- default:
- break;
- }
- atom.setSection(Section::find(atom.getSectionName(), atom.getSegment().getName(), atom.isZeroFill(), untrusted));
- }
-}
-
-
-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* sOverridePathlibLTO = NULL;
-static const char* pathLeafName(const char* path)
+//
+// This is magic glue that overrides the default behaviour
+// of lazydylib1.o which is used to lazily load libLTO.dylib.
+//
+extern "C" const char* dyld_lazy_dylib_path_fix(const char* path);
+const char* dyld_lazy_dylib_path_fix(const char* path)
{
- const char* shortPath = strrchr(path, '/');
- if ( shortPath == NULL )
- return path;
+ if ( sOverridePathlibLTO != NULL )
+ return sOverridePathlibLTO;
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;
- }
- }
- }
- }
+ return path;
}
-// 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()
+int main(int argc, const char* argv[])
{
- // 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 ) {
- // might be from -init command line option
- if ( (fOptions.initFunctionName() != NULL) && (strcmp(name, fOptions.initFunctionName()) == 0) ) {
- fprintf(stderr, " -init command line option\n");
- }
- // or might be from exported symbol option
- else if ( fOptions.hasExportMaskList() && fOptions.shouldExport(name) ) {
- fprintf(stderr, " -exported_symbol[s_list] command line option\n");
- }
- else {
- bool isInitialUndefine = false;
- std::vector<const char*>& clundefs = fOptions.initialUndefines();
- for (std::vector<const char*>::iterator uit = clundefs.begin(); uit != clundefs.end(); ++uit) {
- if ( strcmp(*uit, name) == 0 ) {
- isInitialUndefine = true;
- break;
- }
- }
- if ( isInitialUndefine )
- fprintf(stderr, " -u command line option\n");
- }
- ++unresolvableExportsCount;
- }
- // be helpful and check for typos
- bool printedStart = false;
- for (SymbolTable::Mapper::iterator sit=fGlobalSymbolTable.begin(); sit != fGlobalSymbolTable.end(); ++sit) {
- if ( (sit->second != NULL) && (strstr(sit->first, name) != NULL) ) {
- if ( ! printedStart ) {
- fprintf(stderr, " (maybe you meant: %s", sit->first);
- printedStart = true;
- }
- else {
- fprintf(stderr, ", %s ", sit->first);
- }
- }
- }
- if ( printedStart )
- fprintf(stderr, ")\n");
- }
- }
- 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);
- }
- }
- }
- }
- }
- }
+ 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);
+
+ // allow libLTO to be overridden by command line -lto_library
+ sOverridePathlibLTO = options.overridePathlibLTO();
+
+ // 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);
-}
-
-
-
-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;
- }
- }
- }
+ // 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::dedup::doPass(options, state);
+ 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
+ ld::passes::bitcode_bundle::doPass(options, state); // must be after dylib
+
+ // 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;
}
}
-
- // 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
- }
- }
- }
+ catch (const char* msg) {
+ if ( strstr(msg, "malformed") != NULL )
+ fprintf(stderr, "ld: %s\n", msg);
+ else 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;
}
- // 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;
+ return 0;
}
-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)
+#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)
{
- // 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);
-}
+ Snapshot *snapshot = Snapshot::globalSnapshot;
+
+ snapshot->setSnapshotMode(Snapshot::SNAPSHOT_DEBUG);
+ snapshot->createSnapshot();
+ snapshot->recordAssertionMessage("Assertion failed: (%s), function %s, file %s, line %d.\n", failedexpr, func, file, line);
-
-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);
+ 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;
}
+ long offset = (uintptr_t)callStack[i] - (uintptr_t)info.dli_saddr;
+ fprintf(stderr, "%d %p %s + %ld\n", i, callStack[i], symboName, offset);
+ snapshot->recordAssertionMessage("%d %p %s + %ld\n", i, callStack[i], symboName, offset);
}
+ fprintf(stderr, "A linker snapshot was created at:\n\t%s\n", snapshot->rootDir());
+ fprintf(stderr, "ld: Assertion failed: (%s), function %s, file %s, line %d.\n", failedexpr, func, file, line);
+ exit(1);
}
+#endif
-// 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, true);
- 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(§ionName[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[%d]=%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;
-}
-
-
-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 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 ( 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;
- }
- }
- }
- }
- }
-
- }
- return NULL;
-}
-
-
-void Linker::sortSections()
-{
- Section::assignIndexes(fOptions.outputKind() == Options::kObjectFile);
-}
-
-
-//
-// 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());
- }
- ++matchCount;
- }
- else {
- if ( fOptions.printOrderFileStatistics() ) {
- if ( it->objectFileName == NULL )
- warning("can't find match for order_file entry: %s", it->symbolName);
- else
- warning("can't find match for order_file entry: %s/%s", 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%s, %u %s\t%s\n", (*it)->getSectionName(), (*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, 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, true, 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, true, 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, bool searchArchives)
-{
- // 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) && searchArchives ) {
- // <rdar://problem/7043256> ld64 can not find a -e entry point from an archive
- this->addJustInTimeAtoms(fOptions.entryName(), false, true, false);
- 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()
-{
- // <rdar://problem/6933931> ld -r of empty .o file should preserve sub-type
- // <rdar://problem/7049478> empty dylib should have subtype from command line
- if ( fOptions.preferSubArchitecture() && (fOptions.architecture() == CPU_TYPE_ARM) ) {
- fCurrentCpuConstraint = (ObjectFile::Reader::CpuConstraint)fOptions.subArchitecture();
- }
-
- 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),
- fCreateUUID, fCanScatter,
- fCurrentCpuConstraint,
- fRegularDefAtomsThatOverrideADylibsWeakDef,
- fGlobalSymbolTable.hasExternalWeakDefinitions());
-}
-
-const char* Linker::fileArch(const void* p)
-{
- const uint8_t* bytes = (uint8_t*)p;
- const char* result;
- result = mach_o::relocatable::Reader<ppc>::fileKind(bytes);
- if ( result != NULL )
- return result;
- result = mach_o::relocatable::Reader<ppc64>::fileKind(bytes);
- if ( result != NULL )
- return result;
- result = mach_o::relocatable::Reader<x86>::fileKind(bytes);
- if ( result != NULL )
- return result;
- result = mach_o::relocatable::Reader<x86_64>::fileKind(bytes);
- if ( result != NULL )
- return result;
- result = mach_o::relocatable::Reader<arm>::fileKind(bytes);
- if ( result != NULL )
- return result;
-
- result = lto::Reader::fileKind(bytes);
- if ( result != NULL )
- return result;
-
- return "unsupported file format";
-}
-
-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
- bool isFatFile = false;
- const fat_header* fh = (fat_header*)p;
- if ( fh->magic == OSSwapBigToHostInt32(FAT_MAGIC) ) {
- isFatFile = true;
- 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::fileKind((uint8_t*)p) != NULL ) {
- if ( lto::Reader::loaded() ) {
- throwf("file was built for %s which is not the architecture being linked (%s)", fileArch(p), fArchitectureName);
- }
- else {
- const char* libLTO = "libLTO.dylib";
- char ldPath[PATH_MAX];
- char tmpPath[PATH_MAX];
- char libLTOPath[PATH_MAX];
- uint32_t bufSize = PATH_MAX;
- if ( _NSGetExecutablePath(ldPath, &bufSize) != -1 ) {
- if ( realpath(ldPath, tmpPath) != NULL ) {
- char* lastSlash = strrchr(tmpPath, '/');
- if ( lastSlash != NULL )
- strcpy(lastSlash, "/../lib/libLTO.dylib");
- libLTO = tmpPath;
- if ( realpath(tmpPath, libLTOPath) != NULL )
- libLTO = libLTOPath;
- }
- }
- throwf("could not process llvm bitcode object file, because %s could not be loaded", libLTO);
- }
- }
-#endif
- // error handling
- if ( ((fat_header*)p)->magic == OSSwapBigToHostInt32(FAT_MAGIC) ) {
- throwf("missing required architecture %s in file", fArchitectureName);
- }
- else {
- if ( isFatFile )
- throwf("file is universal but does not contain a(n) %s slice", fArchitectureName);
- else
- throwf("file was built for %s which is not the architecture being linked (%s)", fileArch(p), fArchitectureName);
- }
-}
-
-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:
- if ( newAtom.getSymbolTableInclusion() == ObjectFile::Atom::kSymbolTableIn )
- fHasExternalWeakDefinitions = true;
- break;
- case ObjectFile::Atom::kExternalDefinition:
- case ObjectFile::Atom::kExternalWeakDefinition:
- ++fDylibSymbolCount;
- 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::erase(const char* name) {
- fTable.erase(name);
-}
-
-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);
-
- // magic section$start symbol always sorts to the start of its section
- if ( left->getContentType() == ObjectFile::Atom::kSectionStart )
- return true;
- if ( right->getContentType() == ObjectFile::Atom::kSectionStart )
- return false;
-
- // 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
- }
- }
- }
-
- // magic section$end symbol always sorts to the end of its section
- if ( left->getContentType() == ObjectFile::Atom::kSectionEnd )
- return false;
- if ( right->getContentType() == ObjectFile::Atom::kSectionEnd )
- return true;
-
- // 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();
-}
-
-
-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;
-}
projects / apple / ld64.git / blobdiff