--- /dev/null
+/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-*
+ * Copyright (c) 2005-2009 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+// start temp HACK for cross builds
+extern "C" double log2 ( double );
+#define __MATH__
+// end temp HACK for cross builds
+
+
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <sys/sysctl.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <limits.h>
+#include <unistd.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 <string>
+#include <map>
+#include <set>
+#include <string>
+#include <vector>
+#include <list>
+#include <algorithm>
+#include <ext/hash_map>
+#include <dlfcn.h>
+#include <AvailabilityMacros.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); }
+};
+
+class CStringEquals
+{
+public:
+ bool operator()(const char* left, const char* right) const { return (strcmp(left, right) == 0); }
+};
+
+class Section : public ObjectFile::Section
+{
+public:
+ static Section* find(const char* sectionName, const char* segmentName, bool zeroFill, bool createIfNeeded=true);
+ static void assignIndexes();
+ const char* getName() { return fSectionName; }
+private:
+ Section(const char* sectionName, const char* segmentName, bool zeroFill);
+
+ struct Sorter {
+ static int segmentOrdinal(const char* segName);
+ bool operator()(Section* left, Section* right);
+ };
+
+ typedef __gnu_cxx::hash_map<const char*, uint32_t, __gnu_cxx::hash<const char*>, CStringEquals> NameToOrdinal;
+ typedef __gnu_cxx::hash_map<const char*, class Section*, __gnu_cxx::hash<const char*>, CStringEquals> NameToSection;
+ //typedef std::map<const char*, class Section*, CStringComparor> NameToSection;
+
+ char fSectionName[18];
+ char fSegmentName[18];
+ bool fZeroFill;
+
+ static NameToSection fgMapping;
+ static std::vector<Section*> fgSections;
+ static NameToOrdinal fgSegmentDiscoverOrder;
+};
+
+Section::NameToSection Section::fgMapping;
+std::vector<Section*> Section::fgSections;
+Section::NameToOrdinal Section::fgSegmentDiscoverOrder;
+
+Section::Section(const char* sectionName, const char* segmentName, bool zeroFill)
+ : fZeroFill(zeroFill)
+{
+ strlcpy(fSectionName, sectionName, sizeof(fSectionName));
+ strlcpy(fSegmentName, segmentName, sizeof(fSegmentName));
+
+ this->fIndex = fgSections.size() + 20; // room for 20 standard sections
+ // special placement of some sections
+ if ( strcmp(segmentName, "__TEXT") == 0 ) {
+ // sort unwind info to end of segment
+ if ( strcmp(sectionName, "__eh_frame") == 0 )
+ this->fIndex = INT_MAX;
+ else if ( strcmp(sectionName, "__unwind_info") == 0 )
+ this->fIndex = INT_MAX-1;
+ else if ( strcmp(sectionName, "__gcc_except_tab") == 0 )
+ this->fIndex = INT_MAX-2;
+ }
+ else if ( strcmp(segmentName, "__DATA") == 0 ) {
+ // sort sections dyld will touch to start of segment
+ if ( strcmp(sectionName, "__dyld") == 0 )
+ this->fIndex = 1;
+ else if ( strcmp(sectionName, "__program_vars") == 0 )
+ this->fIndex = 1;
+ else if ( strcmp(sectionName, "__mod_init_func") == 0 )
+ this->fIndex = 2;
+ else if ( strcmp(sectionName, "__nl_symbol_ptr") == 0 )
+ this->fIndex = 3;
+ else if ( strcmp(sectionName, "__la_symbol_ptr") == 0 )
+ this->fIndex = 4;
+ else if ( strcmp(sectionName, "__const") == 0 )
+ this->fIndex = 5;
+ else if ( strcmp(sectionName, "__cfstring") == 0 )
+ this->fIndex = 6;
+ else if ( strcmp(sectionName, "__gcc_except_tab") == 0 )
+ this->fIndex = 7;
+ else if ( strcmp(sectionName, "__objc_data") == 0 )
+ this->fIndex = 8;
+ else if ( strcmp(sectionName, "__objc_msgrefs") == 0 )
+ this->fIndex = 9;
+ else if ( strcmp(sectionName, "__objc_protorefs") == 0 )
+ this->fIndex = 10;
+ else if ( strcmp(sectionName, "__objc_selrefs") == 0 )
+ this->fIndex = 11;
+ else if ( strcmp(sectionName, "__objc_classrefs") == 0 )
+ this->fIndex = 12;
+ else if ( strcmp(sectionName, "__objc_superrefs") == 0 )
+ this->fIndex = 13;
+ else if ( strcmp(sectionName, "__objc_const") == 0 )
+ this->fIndex = 14;
+ else if ( strcmp(sectionName, "__objc_classlist") == 0 )
+ this->fIndex = 15;
+ else if ( strcmp(sectionName, "__objc_nlclslist") == 0 )
+ this->fIndex = 16;
+ else if ( strcmp(sectionName, "__objc_catlist") == 0 )
+ this->fIndex = 17;
+ else if ( strcmp(sectionName, "__objc_protolist") == 0 )
+ this->fIndex = 18;
+ else if ( strcmp(sectionName, "__objc_imageinfo") == 0 )
+ this->fIndex = 19;
+
+ }
+
+ //fprintf(stderr, "new Section(%s, %s) => %p, %u\n", sectionName, segmentName, this, this->getIndex());
+}
+
+Section* Section::find(const char* sectionName, const char* segmentName, bool zeroFill, bool createIfNeeded)
+{
+ NameToSection::iterator pos = fgMapping.find(sectionName);
+ if ( pos != fgMapping.end() ) {
+ if ( strcmp(pos->second->fSegmentName, segmentName) == 0 )
+ return pos->second;
+ // otherwise same section name is used in different segments, look slow way
+ for (std::vector<Section*>::iterator it=fgSections.begin(); it != fgSections.end(); it++) {
+ if ( (strcmp((*it)->fSectionName, sectionName) == 0) && (strcmp((*it)->fSegmentName, segmentName) == 0) )
+ return *it;
+ }
+ }
+
+ if ( !createIfNeeded )
+ return NULL;
+
+ // does not exist, so make a new one
+ Section* sect = new Section(sectionName, segmentName, zeroFill);
+ fgMapping[sectionName] = sect;
+ fgSections.push_back(sect);
+
+ if ( (strcmp(sectionName, "__text") == 0) && (strcmp(segmentName, "__TEXT") == 0) ) {
+ // special case __StaticInit to be right after __text
+ find("__StaticInit", "__TEXT", false);
+ }
+
+ // remember segment discovery order
+ if ( fgSegmentDiscoverOrder.find(segmentName) == fgSegmentDiscoverOrder.end() )
+ fgSegmentDiscoverOrder[segmentName] = fgSegmentDiscoverOrder.size();
+
+ return sect;
+}
+
+int Section::Sorter::segmentOrdinal(const char* segName)
+{
+ if ( strcmp(segName, "__HEADER") == 0 )
+ return 1;
+ if ( strcmp(segName, "__PAGEZERO") == 0 )
+ return 1;
+ if ( strcmp(segName, "__TEXT") == 0 )
+ return 2;
+ if ( strcmp(segName, "__DATA") == 0 )
+ return 3;
+ if ( strcmp(segName, "__OBJC") == 0 )
+ return 4;
+ if ( strcmp(segName, "__OBJC2") == 0 )
+ return 5;
+ if ( strcmp(segName, "__LINKEDIT") == 0 )
+ return INT_MAX; // linkedit segment should always sort last
+ else
+ return fgSegmentDiscoverOrder[segName]+6;
+}
+
+
+bool Section::Sorter::operator()(Section* left, Section* right)
+{
+ // Segment is primary sort key
+ int leftSegOrdinal = segmentOrdinal(left->fSegmentName);
+ int rightSegOrdinal = segmentOrdinal(right->fSegmentName);
+ if ( leftSegOrdinal < rightSegOrdinal )
+ return true;
+ if ( leftSegOrdinal > rightSegOrdinal )
+ return false;
+
+ // zerofill section sort to the end
+ if ( !left->fZeroFill && right->fZeroFill )
+ return true;
+ if ( left->fZeroFill && !right->fZeroFill )
+ return false;
+
+ // section discovery order is last sort key
+ return left->fIndex < right->fIndex;
+}
+
+void Section::assignIndexes()
+{
+ //printf("unsorted sections:\n");
+ //for (std::vector<Section*>::iterator it=fgSections.begin(); it != fgSections.end(); it++) {
+ // printf("section: name=%s, segment: name=%s, discovery order=%d\n", (*it)->fSectionName, (*it)->fSegmentName, (*it)->fIndex);
+ //}
+
+ // sort it
+ std::sort(fgSections.begin(), fgSections.end(), Section::Sorter());
+
+ // assign correct section ordering to each Section object
+ unsigned int newOrder = 1;
+ for (std::vector<Section*>::iterator it=fgSections.begin(); it != fgSections.end(); it++)
+ (*it)->fIndex = newOrder++;
+
+ //printf("sorted sections:\n");
+ //for (std::vector<Section*>::iterator it=fgSections.begin(); it != fgSections.end(); it++) {
+ // printf("section: index=%d, obj=%p, name=%s\n", (*it)->fIndex, (*it), (*it)->fSectionName);
+ //}
+}
+
+class Linker : public ObjectFile::Reader::DylibHander {
+public:
+ Linker(int argc, const char* argv[]);
+
+ const char* getArchPrefix();
+ const char* architectureName();
+ bool showArchitectureInErrors();
+ bool isInferredArchitecture();
+ void createReaders();
+ void createWriter();
+ void addInputFile(ObjectFile::Reader* reader, const Options::FileInfo& );
+ void setOutputFile(ExecutableFile::Writer* writer);
+ void link();
+ void optimize();
+
+ // implemenation from ObjectFile::Reader::DylibHander
+ virtual ObjectFile::Reader* findDylib(const char* installPath, const char* fromPath);
+
+private:
+ struct WhyLiveBackChain
+ {
+ WhyLiveBackChain* previous;
+ ObjectFile::Atom* referer;
+ };
+
+ ObjectFile::Reader* createReader(const Options::FileInfo&);
+ void addAtom(ObjectFile::Atom& atom);
+ void addAtoms(std::vector<class ObjectFile::Atom*>& atoms);
+ void buildAtomList();
+ void adjustScope();
+ void processDylibs();
+ void markDead(ObjectFile::Atom* atom);
+ void updateConstraints(ObjectFile::Reader* reader);
+ void loadAndResolve();
+ void processDTrace();
+ void checkObjC();
+ void loadUndefines();
+ void checkUndefines();
+ void resolveReferences();
+ void deadStripResolve();
+ void addLiveRoot(const char* name);
+ void moveToFrontOfSection(ObjectFile::Atom* atom);
+ ObjectFile::Atom* findAtom(const Options::OrderedSymbol& pair);
+ void logArchive(ObjectFile::Reader* reader);
+ void sortSections();
+ void sortAtoms();
+ void tweakLayout();
+ void writeDotOutput();
+ static bool minimizeStab(ObjectFile::Reader::Stab& stab);
+ static const char* truncateStabString(const char* str);
+ void collectDebugInfo();
+ void writeOutput();
+ ObjectFile::Atom* entryPoint(bool orInit);
+ ObjectFile::Atom* dyldClassicHelper();
+ ObjectFile::Atom* dyldCompressedHelper();
+ ObjectFile::Atom* dyldLazyLibraryHelper();
+ const char* assureFullPath(const char* path);
+ void markLive(ObjectFile::Atom& atom, Linker::WhyLiveBackChain* previous);
+ void collectStabs(ObjectFile::Reader* reader, std::map<const class ObjectFile::Atom*, uint32_t>& atomOrdinals);
+ void synthesizeDebugNotes(std::vector<class ObjectFile::Atom*>& allAtomsByReader);
+ void printStatistics();
+ void printTime(const char* msg, uint64_t partTime, uint64_t totalTime);
+ char* commatize(uint64_t in, char* out);
+ void getVMInfo(vm_statistics_data_t& info);
+ cpu_type_t inferArchitecture();
+ void checkDylibClientRestrictions(ObjectFile::Reader* reader);
+ void logDylib(ObjectFile::Reader* reader, bool indirect);
+
+ void resolve(ObjectFile::Reference* reference);
+ void resolveFrom(ObjectFile::Reference* reference);
+ std::vector<class ObjectFile::Atom*>* addJustInTimeAtoms(const char* name, bool searchDylibs, bool searchArchives, bool okToMakeProxy);
+ void addJustInTimeAtomsAndMarkLive(const char* name);
+
+ ObjectFile::Reader* addDylib(ObjectFile::Reader* reader, const Options::FileInfo& info, uint64_t mappedLen);
+ ObjectFile::Reader* addObject(ObjectFile::Reader* reader, const Options::FileInfo& info, uint64_t mappedLen);
+ ObjectFile::Reader* addArchive(ObjectFile::Reader* reader, const Options::FileInfo& info, uint64_t mappedLen);
+
+ void logTraceInfo(const char* format, ...);
+
+
+ class SymbolTable
+ {
+ public:
+ typedef __gnu_cxx::hash_map<const char*, ObjectFile::Atom*, __gnu_cxx::hash<const char*>, CStringEquals> Mapper;
+
+ SymbolTable(Linker&);
+ void require(const char* name);
+ bool add(ObjectFile::Atom& atom);
+ ObjectFile::Atom* find(const char* name);
+ unsigned int getRequireCount() { return fRequireCount; }
+ void getUndefinesNames(std::vector<const char*>& undefines);
+ void getTentativesNames(std::vector<const char*>& tents);
+ bool hasExternalTentativeDefinitions() { return fHasExternalTentativeDefinitions; }
+ bool hasExternalWeakDefinitions() { return fHasExternalWeakDefinitions; }
+ void setHasExternalWeakDefinitions(bool value) { fHasExternalWeakDefinitions = value; }
+ Mapper::iterator begin() { return fTable.begin(); }
+ Mapper::iterator end() { return fTable.end(); }
+
+ private:
+ Linker& fOwner;
+ Mapper fTable;
+ unsigned int fRequireCount;
+ bool fHasExternalTentativeDefinitions;
+ bool fHasExternalWeakDefinitions;
+ };
+
+ class AtomSorter
+ {
+ public:
+ AtomSorter(std::map<const ObjectFile::Atom*, uint32_t>* map, std::set<const ObjectFile::Atom*>& inits,
+ std::set<const ObjectFile::Atom*>& terms) :
+ fOverriddenOrdinalMap(map), fInitializerSet(inits), fTerminatorSet(terms) {}
+ bool operator()(const ObjectFile::Atom* left, const ObjectFile::Atom* right);
+ private:
+ std::map<const ObjectFile::Atom*, uint32_t>* fOverriddenOrdinalMap;
+ std::set<const ObjectFile::Atom*>& fInitializerSet;
+ std::set<const ObjectFile::Atom*>& fTerminatorSet;
+ };
+
+ typedef std::map<const char*, uint32_t, CStringComparor> SectionOrder;
+
+ struct DTraceProbeInfo {
+ DTraceProbeInfo(const ObjectFile::Atom* a, uint32_t o, const char* n) : atom(a), offset(o), probeName(n) {}
+ const ObjectFile::Atom* atom;
+ uint32_t offset;
+ const char* probeName;
+ };
+ typedef __gnu_cxx::hash_map<const char*, std::vector<DTraceProbeInfo>, __gnu_cxx::hash<const char*>, CStringEquals> ProviderToProbes;
+ typedef __gnu_cxx::hash_set<const char*, __gnu_cxx::hash<const char*>, CStringEquals> CStringSet;
+ typedef __gnu_cxx::hash_map<const char*, ObjectFile::Reader*, __gnu_cxx::hash<const char*>, CStringEquals> InstallNameToReader;
+
+ struct IndirectLibrary {
+ const char* path;
+ uint64_t fileLen;
+ ObjectFile::Reader* reader;
+ std::set<ObjectFile::Reader*> parents;
+ ObjectFile::Reader* reExportedViaDirectLibrary;
+ };
+
+ ObjectFile::Reader* findDirectLibraryWhichReExports(struct IndirectLibrary& indirectLib);
+
+ Options fOptions;
+ SymbolTable fGlobalSymbolTable;
+ uint32_t fNextInputOrdinal;
+ std::vector<class ObjectFile::Reader*> fInputFiles;
+ ExecutableFile::Writer* fOutputFile;
+ InstallNameToReader fDylibMap;
+ std::map<ObjectFile::Reader*,LibraryOptions> fDylibOptionsMap;
+ std::set<ObjectFile::Reader*> fDylibsProcessed;
+ ObjectFile::Reader* fBundleLoaderReader;
+ std::vector<class ObjectFile::Reader*> fReadersThatHaveSuppliedAtoms;
+ std::vector<class ObjectFile::Atom*> fAllAtoms;
+ std::set<class ObjectFile::Reader*> fArchiveReaders;
+ std::set<class ObjectFile::Reader*> fArchiveReadersLogged;
+ std::set<class ObjectFile::Atom*> fDeadAtoms;
+ std::set<ObjectFile::Atom*> fLiveAtoms;
+ std::set<ObjectFile::Atom*> fLiveRootAtoms;
+ std::set<const ObjectFile::Atom*> fInitializerAtoms;
+ std::set<const ObjectFile::Atom*> fTerminatorAtoms;
+ std::set<const ObjectFile::Atom*> fRegularDefAtomsThatOverrideADylibsWeakDef;
+ std::vector<class ObjectFile::Reader::Stab> fStabs;
+ std::vector<class ObjectFile::Atom*> fAtomsWithUnresolvedReferences;
+ std::set<class ObjectFile::Atom*> fAtomsOverriddenByLateLoads;
+ bool fInitialLoadsDone;
+ bool fCreateUUID;
+ bool fCanScatter;
+ SectionOrder fSectionOrder;
+ cpu_type_t fArchitecture;
+ const char* fArchitectureName;
+ bool fArchitectureInferred;
+ bool fDirectLibrariesComplete;
+ bool fBiggerThanTwoGigOutput;
+ uint64_t fOutputFileSize;
+ uint64_t fTotalZeroFillSize;
+ uint64_t fTotalSize;
+ uint64_t fStartTime;
+ uint64_t fStartCreateReadersTime;
+ uint64_t fStartCreateWriterTime;
+ uint64_t fStartBuildAtomsTime;
+ uint64_t fStartLoadAndResolveTime;
+ uint64_t fStartSortTime;
+ uint64_t fStartDebugTime;
+ uint64_t fStartWriteTime;
+ uint64_t fEndTime;
+ uint64_t fTotalObjectSize;
+ uint64_t fTotalArchiveSize;
+ uint32_t fTotalObjectLoaded;
+ uint32_t fTotalArchivesLoaded;
+ uint32_t fTotalDylibsLoaded;
+ vm_statistics_data_t fStartVMInfo;
+ ObjectFile::Reader::ObjcConstraint fCurrentObjCConstraint;
+ ObjectFile::Reader::CpuConstraint fCurrentCpuConstraint;
+ bool fObjcReplacmentClasses;
+ bool fAllDirectDylibsLoaded;
+};
+
+
+Linker::Linker(int argc, const char* argv[])
+ : fOptions(argc, argv), fGlobalSymbolTable(*this), fNextInputOrdinal(1), fOutputFile(NULL), fBundleLoaderReader(NULL),
+ fInitialLoadsDone(false), fCreateUUID(fOptions.outputKind() != Options::kObjectFile), fCanScatter(true),
+ fArchitecture(0), fArchitectureInferred(false), fDirectLibrariesComplete(false), fBiggerThanTwoGigOutput(false),
+ fOutputFileSize(0), fTotalZeroFillSize(0), fTotalSize(0), fTotalObjectSize(0),
+ fTotalArchiveSize(0), fTotalObjectLoaded(0), fTotalArchivesLoaded(0), fTotalDylibsLoaded(0),
+ fCurrentObjCConstraint(ObjectFile::Reader::kObjcNone), fCurrentCpuConstraint(ObjectFile::Reader::kCpuAny),
+ fObjcReplacmentClasses(false), fAllDirectDylibsLoaded(false)
+{
+ fStartTime = mach_absolute_time();
+ if ( fOptions.printStatistics() )
+ getVMInfo(fStartVMInfo);
+
+ fArchitecture = fOptions.architecture();
+ if ( fArchitecture == 0 ) {
+ // -arch not specified, scan .o files to figure out what it should be
+ fArchitecture = inferArchitecture();
+ fArchitectureInferred = true;
+ }
+ switch (fArchitecture) {
+ case CPU_TYPE_POWERPC:
+ fArchitectureName = "ppc";
+ 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";
+ break;
+ default:
+ fArchitectureName = "unknown architecture";
+ break;
+ }
+}
+
+const char* Linker::architectureName()
+{
+ return fArchitectureName;
+}
+
+bool Linker::showArchitectureInErrors()
+{
+ return fOptions.printArchPrefix();
+}
+
+bool Linker::isInferredArchitecture()
+{
+ return fArchitectureInferred;
+}
+
+cpu_type_t Linker::inferArchitecture()
+{
+ // 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;
+ }
+ }
+ }
+ }
+
+ // no thin .o files found, so default to same architecture this was built as
+ warning("-arch not specified");
+#if __ppc__
+ return CPU_TYPE_POWERPC;
+#elif __i386__
+ return CPU_TYPE_I386;
+#elif __ppc64__
+ return CPU_TYPE_POWERPC64;
+#elif __x86_64__
+ return CPU_TYPE_X86_64;
+#elif __arm__
+ return CPU_TYPE_ARM;
+#else
+ #error unknown default architecture
+#endif
+}
+
+
+void Linker::addInputFile(ObjectFile::Reader* reader, const Options::FileInfo& info)
+{
+ fInputFiles.push_back(reader);
+ fDylibOptionsMap[reader] = info.options;
+}
+
+void Linker::setOutputFile(ExecutableFile::Writer* writer)
+{
+ fOutputFile = writer;
+}
+
+class InSet
+{
+public:
+ InSet(std::set<ObjectFile::Atom*>& deadAtoms) : fDeadAtoms(deadAtoms) {}
+
+ bool operator()(ObjectFile::Atom*& atom) const {
+ return ( fDeadAtoms.count(atom) != 0 );
+ }
+
+private:
+ std::set<ObjectFile::Atom*>& fDeadAtoms;
+};
+
+void Linker::loadAndResolve()
+{
+ fStartLoadAndResolveTime = mach_absolute_time();
+ if ( fOptions.deadStrip() == Options::kDeadStripOff ) {
+ // without dead-code-stripping:
+ // find atoms to resolve all undefines
+ this->loadUndefines();
+ // verify nothing is missing
+ this->checkUndefines();
+ // once all undefines fulfill, then bind all references
+ this->resolveReferences();
+ // remove atoms weak atoms that have been overridden
+ fAllAtoms.erase(std::remove_if(fAllAtoms.begin(), fAllAtoms.end(), InSet(fDeadAtoms)), fAllAtoms.end());
+ }
+ else {
+ // with dead code stripping:
+ // start binding references from roots,
+ this->deadStripResolve();
+ // verify nothing is missing
+ this->checkUndefines();
+ }
+}
+
+void Linker::optimize()
+{
+ // give each reader a chance to do any optimizations
+ bool didSomething = false;
+ std::vector<class ObjectFile::Atom*> newAtoms;
+ std::vector<const char *> additionalUndefines;
+ std::vector<class ObjectFile::Atom*> newlyDeadAtoms;
+ for (std::vector<class ObjectFile::Reader*>::iterator it=fInputFiles.begin(); it != fInputFiles.end(); it++) {
+ didSomething |= (*it)->optimize(fAllAtoms, newAtoms, additionalUndefines, fDeadAtoms, newlyDeadAtoms, fNextInputOrdinal,
+ fOutputFile, entryPoint(true), fOptions.llvmOptions(),
+ fOptions.allGlobalsAreDeadStripRoots(), (int)fOptions.outputKind(), fOptions.verbose(),
+ fOptions.saveTempFiles(), fOptions.getOutputFilePath(), fOptions.positionIndependentExecutable(),
+ fOptions.allowTextRelocs());
+ }
+
+ // only do next steps if some optimization was actually done
+ if ( didSomething ) {
+ // add all newly created atoms to fAllAtoms and update symbol table
+ this->addAtoms(newAtoms);
+
+ // add dead atoms to dead list and remove from fAllAtoms
+ for(std::vector<class ObjectFile::Atom*>::iterator itr = newlyDeadAtoms.begin(); itr != newlyDeadAtoms.end(); ++itr)
+ markDead(*itr);
+ fAllAtoms.erase(std::remove_if(fAllAtoms.begin(), fAllAtoms.end(), InSet(fDeadAtoms)), fAllAtoms.end());
+
+ // Make sure all atoms have a section. Atoms that were not originally in a mach-o file could
+ // not have their section set until now.
+ for(std::vector<class ObjectFile::Atom*>::iterator itr = fAllAtoms.begin(); itr != fAllAtoms.end(); ++itr) {
+ ObjectFile::Atom *atom = *itr;
+ if ( atom->getSection() == NULL )
+ atom->setSection(Section::find(atom->getSectionName(), atom->getSegment().getName(), atom->isZeroFill()));
+ }
+
+ // resolve new undefines
+ for(std::vector<const char*>::iterator riter = additionalUndefines.begin(); riter != additionalUndefines.end(); ++riter) {
+ const char *targetName = *riter;
+ //fprintf(stderr, "LTO additional undefine: %s\n", targetName);
+ ObjectFile::Atom* target = fGlobalSymbolTable.find(targetName);
+ if ( target == NULL) {
+ // mark that this symbol is needed
+ fGlobalSymbolTable.require(targetName);
+ // try to find it in some library
+ this->addJustInTimeAtoms(targetName, true, true, true);
+ }
+ }
+
+ if ( fOptions.deadStrip() != Options::kDeadStripOff ) {
+ // LTO may optimize away some atoms, so dead stripping must be redone
+ fLiveAtoms.clear();
+ this->deadStripResolve();
+ }
+ 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 ) {
+ // we do have an exported weak symbol, turn WEAK_DEFINES back on
+ fGlobalSymbolTable.setHasExternalWeakDefinitions(true);
+ }
+ }
+ 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());
+ }
+ }
+ }
+ }
+ }
+
+ // linking is done, so demote hidden symbols to static
+ if ( (fOptions.outputKind() == Options::kObjectFile) && fOptions.keepPrivateExterns() ) {
+ // ld -r -keep_private_externs does not move hidden symbols to static
+ }
+ else {
+ for(std::vector<class ObjectFile::Atom*>::iterator itr = fAllAtoms.begin(); itr != fAllAtoms.end(); ++itr) {
+ ObjectFile::Atom *atom = *itr;
+ // <rdar://problem/4637139> hidden common symbols cannot be demoted to static
+ if ( (atom->getScope() == ObjectFile::Atom::scopeLinkageUnit) && (atom->getDefinitionKind() != ObjectFile::Atom::kTentativeDefinition) ) {
+ atom->setScope(ObjectFile::Atom::scopeTranslationUnit);
+ //fprintf(stderr, "demote %s to static\n", atom->getDisplayName());
+ }
+ }
+ }
+}
+
+void Linker::link()
+{
+ this->buildAtomList();
+ this->loadAndResolve();
+ this->optimize();
+ this->adjustScope();
+ this->checkObjC();
+ this->processDTrace();
+ this->tweakLayout();
+ this->sortSections();
+ this->sortAtoms();
+ this->writeDotOutput();
+ this->collectDebugInfo();
+ this->writeOutput();
+ this->printStatistics();
+
+ if ( fOptions.pauseAtEnd() )
+ sleep(10);
+}
+
+void Linker::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 ( 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);
+ }
+ 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);
+ }
+}
+
+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)
+{
+ 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,
+ (host_info_t)&info, &count);
+ if (error != KERN_SUCCESS) {
+ bzero(&info, sizeof(vm_statistics_data_t));
+ }
+}
+
+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())
+ atom.setSection(Section::find(atom.getSectionName(), atom.getSegment().getName(), atom.isZeroFill()));
+}
+
+
+void Linker::markDead(ObjectFile::Atom* atom)
+{
+ //fprintf(stderr, "markDead(%p) %s from %s\n", atom, atom->getDisplayName(), atom->getFile()->getPath());
+ fDeadAtoms.insert(atom);
+
+ // <rdar://problem/6578360> -dead_strip inhibits weak coalescing in no_dead_strip section
+ if ( fLiveRootAtoms.count(atom) != 0 ) {
+ fLiveRootAtoms.erase(atom);
+ }
+
+ //
+ // The kGroupSubordinate reference kind is used to model group comdat.
+ // The "signature" atom in the group has a kGroupSubordinate reference to
+ // all other members of the group. So, if the signature atom is
+ // coalesced away, all other atoms in the group should also be removed.
+ //
+ std::vector<class ObjectFile::Reference*>& references = atom->getReferences();
+ for (std::vector<ObjectFile::Reference*>::iterator rit=references.begin(); rit != references.end(); rit++) {
+ ObjectFile::Reference* ref = *rit;
+ if ( ref->getKind() == 2 /*kGroupSubordinate*/ ) { // FIX FIX
+ ObjectFile::Atom* targetAtom = &(ref->getTarget());
+ //fprintf(stderr, " markDead(%p) subordinate %s\n", targetAtom, targetAtom->getDisplayName());
+ if ( targetAtom == NULL ) {
+ warning("%s has a group reference to %s but is not bound", atom->getDisplayName(), ref->getTargetName());
+ }
+ else {
+ if ( targetAtom->getScope() != ObjectFile::Atom::scopeTranslationUnit ) {
+ // ok for .eh symbols to be not static in -r mode
+ if ( (fOptions.outputKind() != Options::kObjectFile) || (strcmp(targetAtom->getSectionName(), "__eh_frame") != 0) )
+ warning("%s is in a comdat group but its scope is not static", targetAtom->getDisplayName());
+ }
+ this->markDead(targetAtom);
+ }
+ }
+ }
+}
+
+void Linker::updateConstraints(ObjectFile::Reader* reader)
+{
+ // check objc objects were compiled compatibly
+ ObjectFile::Reader::ObjcConstraint objcAddition = reader->getObjCConstraint();
+ if ( reader->getInstallPath() == NULL ) {
+ // adding a .o file
+ switch ( objcAddition ) {
+ case ObjectFile::Reader::kObjcNone:
+ break;
+ case ObjectFile::Reader::kObjcRetainRelease:
+ if ( fCurrentObjCConstraint == ObjectFile::Reader::kObjcGC )
+ throwf("%s built with incompatible Garbage Collection settings to link with previous .o files", reader->getPath());
+ fCurrentObjCConstraint = ObjectFile::Reader::kObjcRetainRelease;
+ break;
+ case ObjectFile::Reader::kObjcRetainReleaseOrGC:
+ if ( fCurrentObjCConstraint == ObjectFile::Reader::kObjcNone )
+ fCurrentObjCConstraint = ObjectFile::Reader::kObjcRetainReleaseOrGC;
+ break;
+ case ObjectFile::Reader::kObjcGC:
+ if ( fCurrentObjCConstraint == ObjectFile::Reader::kObjcRetainRelease )
+ throwf("%s built with incompatible Garbage Collection settings to link with previous .o files", reader->getPath());
+ fCurrentObjCConstraint = ObjectFile::Reader::kObjcGC;
+ break;
+ }
+ }
+ if ( reader->objcReplacementClasses() )
+ fObjcReplacmentClasses = true;
+
+ // check cpu sub-types for stricter sub-type
+ fCurrentCpuConstraint = (ObjectFile::Reader::CpuConstraint)reader->updateCpuConstraint(fCurrentCpuConstraint);
+}
+
+inline void Linker::addAtoms(std::vector<class ObjectFile::Atom*>& atoms)
+{
+ bool scanAll = fOptions.readerOptions().fFullyLoadArchives || fOptions.readerOptions().fLoadAllObjcObjectsFromArchives;
+ bool first = true;
+ for (std::vector<ObjectFile::Atom*>::iterator it=atoms.begin(); it != atoms.end(); it++) {
+ // usually we only need to get the first atom's reader, but
+ // with -all_load all atoms from all .o files come come back together
+ // so we need to scan all atoms
+ if ( first || scanAll ) {
+ // update fReadersThatHaveSuppliedAtoms
+ ObjectFile::Reader* reader = (*it)->getFile();
+ if ( std::find(fReadersThatHaveSuppliedAtoms.begin(), fReadersThatHaveSuppliedAtoms.end(), reader)
+ == fReadersThatHaveSuppliedAtoms.end() ) {
+ fReadersThatHaveSuppliedAtoms.push_back(reader);
+ updateConstraints(reader);
+ }
+ }
+ this->addAtom(**it);
+ first = false;
+ }
+}
+
+void Linker::logArchive(ObjectFile::Reader* reader)
+{
+ if ( (fArchiveReaders.count(reader) != 0) && (fArchiveReadersLogged.count(reader) == 0) ) {
+ fArchiveReadersLogged.insert(reader);
+ const char* fullPath = reader->getPath();
+ char realName[MAXPATHLEN];
+ if ( realpath(fullPath, realName) != NULL )
+ fullPath = realName;
+ logTraceInfo("[Logging for XBS] Used static archive: %s\n", fullPath);
+ }
+}
+
+
+void Linker::buildAtomList()
+{
+ fStartBuildAtomsTime = mach_absolute_time();
+ // add initial undefines from -u option
+ std::vector<const char*>& initialUndefines = fOptions.initialUndefines();
+ for (std::vector<const char*>::iterator it=initialUndefines.begin(); it != initialUndefines.end(); it++) {
+ fGlobalSymbolTable.require(*it);
+ }
+
+ // writer can contribute atoms
+ this->addAtoms(fOutputFile->getAtoms());
+
+ // each reader contributes atoms
+ for (std::vector<class ObjectFile::Reader*>::iterator it=fInputFiles.begin(); it != fInputFiles.end(); it++) {
+ ObjectFile::Reader* reader = *it;
+ std::vector<class ObjectFile::Atom*>& atoms = reader->getAtoms();
+ this->addAtoms(atoms);
+ if ( fOptions.readerOptions().fTraceArchives && (atoms.size() != 0) )
+ logArchive(reader);
+ }
+
+ // extra command line section always at end
+ std::vector<Options::ExtraSection>& extraSections = fOptions.extraSections();
+ for( std::vector<Options::ExtraSection>::iterator it=extraSections.begin(); it != extraSections.end(); ++it) {
+ this->addAtoms((new opaque_section::Reader(it->segmentName, it->sectionName, it->path, it->data, it->dataLen, fNextInputOrdinal))->getAtoms());
+ fNextInputOrdinal += it->dataLen;
+ }
+
+ // done with all .o files on command line
+ // everything loaded from now on is a just-in-time atom
+ fInitialLoadsDone = true;
+}
+
+static const char* pathLeafName(const char* path)
+{
+ const char* shortPath = strrchr(path, '/');
+ if ( shortPath == NULL )
+ return path;
+ else
+ return &shortPath[1];
+}
+
+
+void Linker::loadUndefines()
+{
+ // keep looping until no more undefines were added in last loop
+ unsigned int undefineCount = 0xFFFFFFFF;
+ while ( undefineCount != fGlobalSymbolTable.getRequireCount() ) {
+ undefineCount = fGlobalSymbolTable.getRequireCount();
+ std::vector<const char*> undefineNames;
+ fGlobalSymbolTable.getUndefinesNames(undefineNames);
+ for(std::vector<const char*>::iterator it = undefineNames.begin(); it != undefineNames.end(); ++it) {
+ // load for previous undefine may also have loaded this undefine, so check again
+ if ( fGlobalSymbolTable.find(*it) == NULL ) {
+ std::vector<class ObjectFile::Atom*>* atoms = this->addJustInTimeAtoms(*it, true, true, true);
+ if ( atoms != NULL )
+ delete atoms;
+ }
+ }
+ // <rdar://problem/5894163> need to search archives for overrides of common symbols
+ if ( fGlobalSymbolTable.hasExternalTentativeDefinitions() ) {
+ bool searchDylibs = (fOptions.commonsMode() == Options::kCommonsOverriddenByDylibs);
+ std::vector<const char*> tentativeDefinitionNames;
+ fGlobalSymbolTable.getTentativesNames(tentativeDefinitionNames);
+ for(std::vector<const char*>::iterator it = tentativeDefinitionNames.begin(); it != tentativeDefinitionNames.end(); ++it) {
+ // load for previous tentative may also have overridden this tentative, so check again
+ ObjectFile::Atom* tent = fGlobalSymbolTable.find(*it);
+ if ( (tent != NULL) && (tent->getDefinitionKind() == ObjectFile::Atom::kTentativeDefinition) ) {
+ std::vector<class ObjectFile::Atom*>* atoms = this->addJustInTimeAtoms(*it, searchDylibs, true, false);
+ if ( atoms != NULL )
+ delete atoms;
+ }
+ }
+ }
+ }
+}
+
+// temp hack for rdar://problem/4718189 map ObjC class names to new runtime names
+class ExportedObjcClass
+{
+public:
+ ExportedObjcClass(Options& opt) : fOptions(opt) {}
+
+ bool operator()(const char* name) const {
+ if ( fOptions.shouldExport(name) ) {
+ if ( strncmp(name, ".objc_class_name_", 17) == 0 )
+ return true;
+ if ( strncmp(name, "_OBJC_CLASS_$_", 14) == 0 )
+ return true;
+ if ( strncmp(name, "_OBJC_METACLASS_$_", 18) == 0 )
+ return true;
+ }
+ //fprintf(stderr, "%s is not exported\n", name);
+ return false;
+ }
+private:
+ Options& fOptions;
+};
+
+
+void Linker::checkUndefines()
+{
+ // error out on any remaining undefines
+ bool doPrint = true;
+ bool doError = true;
+ switch ( fOptions.undefinedTreatment() ) {
+ case Options::kUndefinedError:
+ break;
+ case Options::kUndefinedDynamicLookup:
+ doError = false;
+ break;
+ case Options::kUndefinedWarning:
+ doError = false;
+ break;
+ case Options::kUndefinedSuppress:
+ doError = false;
+ doPrint = false;
+ break;
+ }
+ std::vector<const char*> unresolvableUndefines;
+ fGlobalSymbolTable.getUndefinesNames(unresolvableUndefines);
+
+ // temp hack for rdar://problem/4718189 map ObjC class names to new runtime names
+ // ignore unresolved references to Objc class names that are listed in -exported_symbols_list
+ if ( fOptions.hasExportRestrictList() )
+ unresolvableUndefines.erase(std::remove_if(unresolvableUndefines.begin(), unresolvableUndefines.end(), ExportedObjcClass(fOptions)), unresolvableUndefines.end());
+
+ const int unresolvableCount = unresolvableUndefines.size();
+ int unresolvableExportsCount = 0;
+ if ( unresolvableCount != 0 ) {
+ if ( doPrint ) {
+ if ( fOptions.printArchPrefix() )
+ fprintf(stderr, "Undefined symbols for architecture %s:\n", fArchitectureName);
+ else
+ fprintf(stderr, "Undefined symbols:\n");
+ for (int i=0; i < unresolvableCount; ++i) {
+ const char* name = unresolvableUndefines[i];
+ fprintf(stderr, " \"%s\", referenced from:\n", name);
+ // scan all atoms for references
+ bool foundAtomReference = false;
+ for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
+ ObjectFile::Atom* atom = *it;
+ std::vector<class ObjectFile::Reference*>& references = atom->getReferences();
+ for (std::vector<ObjectFile::Reference*>::iterator rit=references.begin(); rit != references.end(); rit++) {
+ ObjectFile::Reference* reference = *rit;
+ if ( reference->getTargetBinding() == ObjectFile::Reference::kUnboundByName ) {
+ if ( strcmp(reference->getTargetName(), name) == 0 ) {
+ fprintf(stderr, " %s in %s\n", atom->getDisplayName(), pathLeafName(atom->getFile()->getPath()));
+ foundAtomReference = true;
+ }
+ }
+ if ( reference->getFromTargetBinding() == ObjectFile::Reference::kUnboundByName ) {
+ if ( strcmp(reference->getFromTargetName(), name) == 0 ) {
+ fprintf(stderr, " %s in %s\n", atom->getDisplayName(), pathLeafName(atom->getFile()->getPath()));
+ foundAtomReference = true;
+ }
+ }
+ }
+ }
+ // scan command line options
+ if ( !foundAtomReference && fOptions.hasExportRestrictList() && fOptions.shouldExport(name) ) {
+ fprintf(stderr, " -exported_symbols_list command line option\n");
+ ++unresolvableExportsCount;
+ }
+ }
+ }
+ if ( doError )
+ throw "symbol(s) not found";
+ }
+
+ // for each tentative definition in symbol table look for dylib that exports same symbol name
+ if ( fGlobalSymbolTable.hasExternalTentativeDefinitions() ) {
+ for (SymbolTable::Mapper::iterator it=fGlobalSymbolTable.begin(); it != fGlobalSymbolTable.end(); ++it) {
+ ObjectFile::Atom* atom = it->second;
+ if ( (atom != NULL) && (atom->getDefinitionKind()==ObjectFile::Atom::kTentativeDefinition)
+ && (atom->getScope() == ObjectFile::Atom::scopeGlobal) ) {
+ // look for dylibs that export same name as used by global tentative definition
+ addJustInTimeAtoms(atom->getName(), true, false, false);
+ }
+ }
+ }
+
+
+ // record any overrides of weak symbols any linked dylib
+ for (SymbolTable::Mapper::iterator it=fGlobalSymbolTable.begin(); it != fGlobalSymbolTable.end(); ++it) {
+ ObjectFile::Atom* atom = it->second;
+ if ( (atom != NULL) && (atom->getDefinitionKind()==ObjectFile::Atom::kRegularDefinition)
+ && (atom->getScope() == ObjectFile::Atom::scopeGlobal) ) {
+ const char* name = atom->getName();
+ //fprintf(stderr, "looking for dylibs with a weak %s\n", name);
+ // look for dylibs with weak exports of the same name
+ for (InstallNameToReader::iterator it=fDylibMap.begin(); it != fDylibMap.end(); it++) {
+ ObjectFile::Reader* reader = it->second;
+ if ( reader->hasWeakExternals() ) {
+ std::vector<class ObjectFile::Atom*>* dylibAtoms = reader->getJustInTimeAtomsFor(name);
+ if ( dylibAtoms != NULL ) {
+ //fprintf(stderr, "addJustInTimeAtoms(%s) => found in file %s\n", name, reader->getPath() );
+ // if this is a weak definition in a dylib
+ if ( (dylibAtoms->at(0)->getDefinitionKind() == ObjectFile::Atom::kExternalWeakDefinition) ) {
+ fRegularDefAtomsThatOverrideADylibsWeakDef.insert(atom);
+ }
+ }
+ }
+ }
+ }
+ }
+
+}
+
+
+
+std::vector<class ObjectFile::Atom*>* Linker::addJustInTimeAtoms(const char* name, bool searchDylibs, bool searchArchives, bool okToMakeProxy)
+{
+ //fprintf(stderr, "addJustInTimeAtoms(%s, searchDylibs=%d, searchArchives=%d)\n", name, searchDylibs, searchArchives );
+ // when creating final linked image, writer gets first chance
+ if ( fOptions.outputKind() != Options::kObjectFile ) {
+ std::vector<class ObjectFile::Atom*>* atoms = fOutputFile->getJustInTimeAtomsFor(name);
+ if ( atoms != NULL ) {
+ this->addAtoms(*atoms);
+ //fprintf(stderr, "addJustInTimeAtoms(%s) => found in file %s\n", name, fOutputFile->getPath() );
+ return atoms; // found a definition, no need to search anymore
+ }
+ }
+
+ // give readers a chance
+ for (std::vector<class ObjectFile::Reader*>::iterator it=fInputFiles.begin(); it != fInputFiles.end(); it++) {
+ ObjectFile::Reader* reader = *it;
+ if ( reader != NULL ) {
+ // if this reader is a static archive that has the symbol we need, pull in all atoms in that module
+ // if this reader is a dylib that exports the symbol we need, have it synthesize an atom for us.
+ //fprintf(stderr, "addJustInTimeAtoms(%s), looking in reader %s\n", name, reader->getPath() );
+ bool isDylibReader = (reader->getInstallPath() != NULL);
+ if ( isDylibReader ? searchDylibs : searchArchives ) {
+ std::vector<class ObjectFile::Atom*>* atoms = reader->getJustInTimeAtomsFor(name);
+ if ( atoms != NULL ) {
+ this->addAtoms(*atoms);
+ //fprintf(stderr, "addJustInTimeAtoms(%s) => found in file %s\n", name, reader->getPath() );
+ if ( !isDylibReader && fOptions.readerOptions().fTraceArchives ) {
+ logArchive(reader);
+ }
+ // if this is a weak definition in a dylib
+ if ( isDylibReader && (atoms->size() == 1) && (atoms->at(0)->getDefinitionKind() == ObjectFile::Atom::kExternalWeakDefinition) ) {
+ // keep looking for a non-weak definition
+ }
+ else {
+ // found a definition, no need to search anymore
+ return atoms;
+ }
+ }
+ }
+ }
+ }
+
+ // for two level namesapce, give all implicitly link dylibs a chance
+ if ( fOptions.nameSpace() == Options::kTwoLevelNameSpace ) {
+ for (InstallNameToReader::iterator it=fDylibMap.begin(); it != fDylibMap.end(); it++) {
+ if ( it->second->implicitlyLinked() ) {
+ //fprintf(stderr, "addJustInTimeAtoms(%s), looking in implicitly linked %s\n", name, it->second->getPath() );
+ std::vector<class ObjectFile::Atom*>* atoms = it->second->getJustInTimeAtomsFor(name);
+ if ( atoms != NULL ) {
+ this->addAtoms(*atoms);
+ //fprintf(stderr, "addJustInTimeAtoms(%s) => found in file %s\n", name, reader->getPath() );
+ // if this is a weak definition in a dylib
+ if ( (atoms->size() == 1) && (atoms->at(0)->getDefinitionKind() == ObjectFile::Atom::kExternalWeakDefinition) ) {
+ // keep looking for a non-weak definition
+ }
+ else {
+ // found a definition, no need to search anymore
+ return atoms;
+ }
+ }
+ }
+ }
+ }
+
+ // for flat namespace, give indirect dylibs
+ if ( fOptions.nameSpace() != Options::kTwoLevelNameSpace ) {
+ for (InstallNameToReader::iterator it=fDylibMap.begin(); it != fDylibMap.end(); it++) {
+ if ( ! it->second->explicitlyLinked() ) {
+ std::vector<class ObjectFile::Atom*>* atoms = it->second->getJustInTimeAtomsFor(name);
+ if ( atoms != NULL ) {
+ this->addAtoms(*atoms);
+ //fprintf(stderr, "addJustInTimeAtoms(%s) => found in file %s\n", name, reader->getPath() );
+ return atoms; // found a definition, no need to search anymore
+ }
+ }
+ }
+ }
+
+ // writer creates a proxy in two cases:
+ // 1) ld -r is being used to create a .o file
+ // 2) -undefined dynamic_lookup is being used
+ // 3) -U _foo is being used
+ // 4) x86_64 kext bundle is being created
+ if ( (fOptions.outputKind() == Options::kObjectFile)
+ || ((fOptions.undefinedTreatment() != Options::kUndefinedError) && okToMakeProxy)
+ || (fOptions.someAllowedUndefines() && okToMakeProxy)
+ || (fOptions.outputKind() == Options::kKextBundle) ) {
+ ObjectFile::Atom* atom = fOutputFile->getUndefinedProxyAtom(name);
+ if ( atom != NULL ) {
+ this->addAtom(*atom);
+ return NULL;
+ }
+ }
+ //fprintf(stderr, "addJustInTimeAtoms(%s) => not found\n", name);
+ return NULL;
+}
+
+void Linker::resolve(ObjectFile::Reference* reference)
+{
+ // look in global symbol table
+ const char* targetName = reference->getTargetName();
+ ObjectFile::Atom* target = fGlobalSymbolTable.find(targetName);
+ if ( target == NULL ) {
+ throwf("unexpected undefined symbol: %s", targetName);
+ }
+ reference->setTarget(*target, reference->getTargetOffset());
+}
+
+void Linker::resolveFrom(ObjectFile::Reference* reference)
+{
+ // handle references that have two (from and to) targets
+ const char* fromTargetName = reference->getFromTargetName();
+ ObjectFile::Atom* fromTarget = fGlobalSymbolTable.find(fromTargetName);
+ if ( fromTarget == NULL ) {
+ throwf("unexpected undefined symbol: %s", fromTargetName);
+ }
+ reference->setFromTarget(*fromTarget);
+}
+
+
+void Linker::resolveReferences()
+{
+ // note: the atom list may grow during this loop as libraries supply needed atoms
+ for (unsigned int j=0; j < fAllAtoms.size(); ++j) {
+ ObjectFile::Atom* atom = fAllAtoms[j];
+ std::vector<class ObjectFile::Reference*>& references = atom->getReferences();
+ for (std::vector<ObjectFile::Reference*>::iterator it=references.begin(); it != references.end(); it++) {
+ ObjectFile::Reference* reference = *it;
+ if ( reference->getTargetBinding() == ObjectFile::Reference::kUnboundByName )
+ this->resolve(reference);
+ if ( reference->getFromTargetBinding() == ObjectFile::Reference::kUnboundByName )
+ this->resolveFrom(reference);
+ }
+ }
+}
+
+
+// used to remove stabs associated with atoms that won't be in output file
+class NotInSet
+{
+public:
+ NotInSet(std::set<ObjectFile::Atom*>& theSet) : fSet(theSet) {}
+
+ bool operator()(const ObjectFile::Reader::Stab& stab) const {
+ if ( stab.atom == NULL )
+ return false; // leave stabs that are not associated with any atome
+ else
+ return ( fSet.count(stab.atom) == 0 );
+ }
+
+private:
+ std::set<ObjectFile::Atom*>& fSet;
+};
+
+
+class NotLive
+{
+public:
+ NotLive(std::set<ObjectFile::Atom*>& set) : fLiveAtoms(set) {}
+
+ bool operator()(ObjectFile::Atom*& atom) const {
+ //if ( fLiveAtoms.count(atom) == 0 )
+ // fprintf(stderr, "dead strip %s\n", atom->getDisplayName());
+ return ( fLiveAtoms.count(atom) == 0 );
+ }
+private:
+ std::set<ObjectFile::Atom*>& fLiveAtoms;
+};
+
+
+void Linker::addJustInTimeAtomsAndMarkLive(const char* name)
+{
+ //fprintf(stderr, "addJustInTimeAtomsAndMarkLive(%s)\n", name);
+ std::vector<class ObjectFile::Atom*>* atoms = this->addJustInTimeAtoms(name, true, true, true);
+ if ( atoms != NULL ) {
+ if ( fOptions.allGlobalsAreDeadStripRoots() ) {
+ for (std::vector<ObjectFile::Atom*>::iterator it=atoms->begin(); it != atoms->end(); it++) {
+ ObjectFile::Atom* atom = *it;
+ if ( atom->getScope() == ObjectFile::Atom::scopeGlobal ) {
+ WhyLiveBackChain rootChain;
+ rootChain.previous = NULL;
+ rootChain.referer = atom;
+ this->markLive(*atom, &rootChain);
+ }
+ }
+ }
+ delete atoms;
+ }
+}
+
+void Linker::markLive(ObjectFile::Atom& atom, struct Linker::WhyLiveBackChain* previous)
+{
+ //fprintf(stderr, "markLive(%p)\n", &atom);
+ if ( fLiveAtoms.count(&atom) == 0 ) {
+ // if -why_live cares about this symbol, then dump chain
+ if ( (previous->referer != NULL) && fOptions.printWhyLive(previous->referer->getDisplayName()) ) {
+ int depth = 0;
+ for(WhyLiveBackChain* p = previous; p != NULL; p = p->previous, ++depth) {
+ for(int i=depth; i > 0; --i)
+ fprintf(stderr, " ");
+ fprintf(stderr, "%p %s from %s\n", p->referer, p->referer->getDisplayName(), p->referer->getFile()->getPath());
+ }
+ }
+ // set up next chain
+ WhyLiveBackChain thisChain;
+ thisChain.previous = previous;
+ // this atom is live
+ fLiveAtoms.insert(&atom);
+ // update total size info (except for __ZEROPAGE atom)
+ if ( atom.getSegment().isContentReadable() ) {
+ fTotalSize += atom.getSize();
+ if ( atom.isZeroFill() )
+ fTotalZeroFillSize += atom.getSize();
+ }
+ // and all atoms it references
+ std::vector<class ObjectFile::Reference*>& references = atom.getReferences();
+ for (std::vector<ObjectFile::Reference*>::iterator it=references.begin(); it != references.end(); it++) {
+ ObjectFile::Reference* reference = *it;
+ if ( reference->getTargetBinding() == ObjectFile::Reference::kUnboundByName ) {
+ // look in global symbol table
+ const char* targetName = reference->getTargetName();
+ ObjectFile::Atom* target = fGlobalSymbolTable.find(targetName);
+ if ( (target == NULL) || (target->getDefinitionKind() == ObjectFile::Atom::kTentativeDefinition) ) {
+ // load archives or dylibs
+ this->addJustInTimeAtomsAndMarkLive(targetName);
+ }
+ // look again
+ target = fGlobalSymbolTable.find(targetName);
+ if ( target != NULL ) {
+ reference->setTarget(*target, reference->getTargetOffset());
+ }
+ else {
+ // mark as undefined, for later error processing
+ fAtomsWithUnresolvedReferences.push_back(&atom);
+ fGlobalSymbolTable.require(targetName);
+ }
+ }
+ switch ( reference->getTargetBinding() ) {
+ case ObjectFile::Reference::kBoundDirectly:
+ case ObjectFile::Reference::kBoundByName:
+ thisChain.referer = &reference->getTarget();
+ markLive(reference->getTarget(), &thisChain);
+ break;
+ case ObjectFile::Reference::kDontBind:
+ case ObjectFile::Reference::kUnboundByName:
+ // do nothing
+ break;
+ }
+ // do the same as above, for "from target"
+ if ( reference->getFromTargetBinding() == ObjectFile::Reference::kUnboundByName ) {
+ // look in global symbol table
+ const char* targetName = reference->getFromTargetName();
+ ObjectFile::Atom* target = fGlobalSymbolTable.find(targetName);
+ if ( (target == NULL) || (target->getDefinitionKind() == ObjectFile::Atom::kTentativeDefinition) ) {
+ // load archives or dylibs
+ this->addJustInTimeAtomsAndMarkLive(targetName);
+ }
+ // look again
+ target = fGlobalSymbolTable.find(targetName);
+ if ( target != NULL ) {
+ reference->setFromTarget(*target);
+ }
+ else {
+ // mark as undefined, for later error processing
+ fGlobalSymbolTable.require(targetName);
+ }
+ }
+ switch ( reference->getFromTargetBinding() ) {
+ case ObjectFile::Reference::kBoundDirectly:
+ case ObjectFile::Reference::kBoundByName:
+ thisChain.referer = &reference->getFromTarget();
+ markLive(reference->getFromTarget(), &thisChain);
+ break;
+ case ObjectFile::Reference::kUnboundByName:
+ case ObjectFile::Reference::kDontBind:
+ // do nothing
+ break;
+ }
+ }
+ }
+}
+
+
+void Linker::addLiveRoot(const char* name)
+{
+ ObjectFile::Atom* target = fGlobalSymbolTable.find(name);
+ if ( target == NULL ) {
+ this->addJustInTimeAtomsAndMarkLive(name);
+ target = fGlobalSymbolTable.find(name);
+ }
+ if ( target != NULL )
+ fLiveRootAtoms.insert(target);
+}
+
+void Linker::moveToFrontOfSection(ObjectFile::Atom* atom)
+{
+ // check if already moved to front
+ if ( fInitializerAtoms.find(atom) == fInitializerAtoms.end() ) {
+ // don't re-order initializers from .o files without MH_SUBSECTIONS_VIA_SYMBOLS
+ // since that could make all atoms in the file look like initializers
+ if ( atom->getFile()->canScatterAtoms() ) {
+ //fprintf(stdout, "marking as initializer: %s\n", atom->getDisplayName());
+ fInitializerAtoms.insert(atom);
+ // mark all functions that this function references
+ std::vector<class ObjectFile::Reference*>& references = atom->getReferences();
+ for (std::vector<ObjectFile::Reference*>::const_iterator rit=references.begin(); rit != references.end(); rit++) {
+ ObjectFile::Atom* childAtom = &((*rit)->getTarget());
+ if ( childAtom != NULL ) {
+ if ( (*rit)->isBranch() ) {
+ this->moveToFrontOfSection(childAtom);
+ }
+ else if ( (childAtom->getName() != NULL) && (strncmp(childAtom->getName(), "___tcf_", 7) == 0) ) {
+ //fprintf(stdout, "marking as terminator: %s\n", childAtom->getDisplayName());
+ fTerminatorAtoms.insert(childAtom);
+ }
+ }
+ }
+ }
+ }
+}
+
+void Linker::deadStripResolve()
+{
+ // add main() to live roots
+ ObjectFile::Atom* entryPoint = this->entryPoint(false);
+ if ( entryPoint != NULL )
+ fLiveRootAtoms.insert(entryPoint);
+
+ // add dyld_stub_binding_helper/dyld_stub_binder to live roots
+ ObjectFile::Atom* dyldHelper = this->dyldClassicHelper();
+ if ( dyldHelper != NULL )
+ fLiveRootAtoms.insert(dyldHelper);
+ dyldHelper = this->dyldCompressedHelper();
+ if ( dyldHelper != NULL )
+ fLiveRootAtoms.insert(dyldHelper);
+
+ // if using lazy dylib loading, add dyld_lazy_dylib_stub_binding_helper() to live roots
+ if ( fOptions.usingLazyDylibLinking() ) {
+ ObjectFile::Atom* dyldLazyDylibHelper = this->dyldLazyLibraryHelper();
+ if ( dyldLazyDylibHelper != NULL )
+ fLiveRootAtoms.insert(dyldLazyDylibHelper);
+ }
+
+ // add -exported_symbols_list, -init, and -u entries to live roots
+ std::vector<const char*>& initialUndefines = fOptions.initialUndefines();
+ for (std::vector<const char*>::iterator it=initialUndefines.begin(); it != initialUndefines.end(); it++)
+ addLiveRoot(*it);
+
+ // if -exported_symbols_list that has wildcards, we need to find all matches and make them the roots
+ // <rdar://problem/5524973>
+ if ( fOptions.hasWildCardExportRestrictList() ) {
+ for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
+ ObjectFile::Atom* atom = *it;
+ if ( (atom->getScope() == ObjectFile::Atom::scopeGlobal)
+ && (fDeadAtoms.count(atom) == 0)
+ && fOptions.shouldExport(atom->getName()) )
+ fLiveRootAtoms.insert(atom);
+ }
+ }
+
+ // in some cases, every global scope atom in initial .o files is a root
+ if ( fOptions.allGlobalsAreDeadStripRoots() ) {
+ for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
+ ObjectFile::Atom* atom = *it;
+ if ( (atom->getScope() == ObjectFile::Atom::scopeGlobal) && (fDeadAtoms.count(atom) == 0) )
+ fLiveRootAtoms.insert(atom);
+ }
+ }
+
+ // mark all roots as live, and all atoms they reference
+ for (std::set<ObjectFile::Atom*>::iterator it=fLiveRootAtoms.begin(); it != fLiveRootAtoms.end(); it++) {
+ WhyLiveBackChain rootChain;
+ rootChain.previous = NULL;
+ rootChain.referer = *it;
+ markLive(**it, &rootChain);
+ }
+
+ // it is possible that there are unresolved references that can be resolved now
+ // this can happen if the first reference to a common symbol in an archive.
+ // common symbols are not in the archive TOC, but the .o could have been pulled in later.
+ // <rdar://problem/4654131> ld64 while linking cc1 [ when dead_strip is ON]
+ for (std::vector<ObjectFile::Atom*>::iterator it=fAtomsWithUnresolvedReferences.begin(); it != fAtomsWithUnresolvedReferences.end(); it++) {
+ std::vector<class ObjectFile::Reference*>& references = (*it)->getReferences();
+ for (std::vector<ObjectFile::Reference*>::iterator rit=references.begin(); rit != references.end(); rit++) {
+ ObjectFile::Reference* reference = *rit;
+ if ( reference->getTargetBinding() == ObjectFile::Reference::kUnboundByName ) {
+ ObjectFile::Atom* target = fGlobalSymbolTable.find(reference->getTargetName());
+ if ( target != NULL ) {
+ reference->setTarget(*target, reference->getTargetOffset());
+ fLiveAtoms.insert(target);
+ // by just adding this atom to fLiveAtoms set, we are assuming it has no
+ // references, which is true for commons.
+ if ( target->getDefinitionKind() != ObjectFile::Atom::kTentativeDefinition )
+ warning("internal error %s is not a tentative definition", target->getDisplayName());
+ }
+ }
+ if ( reference->getFromTargetBinding() == ObjectFile::Reference::kUnboundByName ) {
+ ObjectFile::Atom* target = fGlobalSymbolTable.find(reference->getFromTargetName());
+ if ( target != NULL ) {
+ reference->setFromTarget(*target);
+ fLiveAtoms.insert(target);
+ // by just adding this atom to fLiveAtoms set, we are assuming it has no
+ // references, which is true for commons.
+ if ( target->getDefinitionKind() != ObjectFile::Atom::kTentativeDefinition )
+ warning("internal error %s is not a tentative definition", target->getDisplayName());
+ }
+ }
+ }
+ }
+
+ // It is possible that some weak symbols were overridden by lazily load objects from archives
+ // and we have some atoms that still refer to the overridden ones.
+ // In that case we need to go back and rebind
+ if ( fAtomsOverriddenByLateLoads.size() > 0 ) {
+ for (std::set<ObjectFile::Atom*>::iterator it=fLiveAtoms.begin(); it != fLiveAtoms.end(); ++it) {
+ ObjectFile::Atom* atom = *it;
+ std::vector<class ObjectFile::Reference*>& references = atom->getReferences();
+ for (std::vector<ObjectFile::Reference*>::iterator rit=references.begin(); rit != references.end(); ++rit) {
+ ObjectFile::Reference* reference = *rit;
+ ObjectFile::Atom* toTarget = &reference->getTarget();
+ if ( fAtomsOverriddenByLateLoads.count(toTarget) ) {
+ //fprintf(stderr, "change reference in %p from %p to %p\n", atom, toTarget, fGlobalSymbolTable.find(toTarget->getName()));
+ reference->setTarget(*fGlobalSymbolTable.find(toTarget->getName()), reference->getTargetOffset());
+ }
+ ObjectFile::Atom* fromTarget = &reference->getFromTarget();
+ if ( (fromTarget != NULL) && fAtomsOverriddenByLateLoads.count(fromTarget) ) {
+ //fprintf(stderr, "change from reference in %p from %p to %p\n", atom, fromTarget, fGlobalSymbolTable.find(fromTarget->getName()));
+ reference->setTarget(*fGlobalSymbolTable.find(fromTarget->getName()), reference->getFromTargetOffset());
+ }
+ }
+ }
+
+ // make sure overriders are live if the atom they overrid was live
+ for (std::set<ObjectFile::Atom*>::iterator it=fAtomsOverriddenByLateLoads.begin(); it != fAtomsOverriddenByLateLoads.end(); ++it) {
+ ObjectFile::Atom* overriderAtom = *it;
+ if ( fLiveAtoms.count(overriderAtom) ) {
+ WhyLiveBackChain rootChain;
+ rootChain.previous = NULL;
+ rootChain.referer = *it;
+ markLive(*fGlobalSymbolTable.find(overriderAtom->getName()), &rootChain);
+ }
+ }
+
+ // remove overridden atoms from fLiveAtoms
+ fAllAtoms.erase(std::remove_if(fAllAtoms.begin(), fAllAtoms.end(), InSet(fAtomsOverriddenByLateLoads)), fAllAtoms.end());
+ fAtomsOverriddenByLateLoads.clear();
+ // remove dead atoms from fLiveAtoms
+ fAllAtoms.erase(std::remove_if(fAllAtoms.begin(), fAllAtoms.end(), InSet(fDeadAtoms)), fAllAtoms.end());
+ }
+
+ // now remove all non-live atoms from fAllAtoms
+ fAllAtoms.erase(std::remove_if(fAllAtoms.begin(), fAllAtoms.end(), NotLive(fLiveAtoms)), fAllAtoms.end());
+}
+
+void Linker::checkObjC()
+{
+ // check dylibs
+ switch ( fCurrentObjCConstraint ) {
+ case ObjectFile::Reader::kObjcNone:
+ // can link against any dylib
+ break;
+ case ObjectFile::Reader::kObjcRetainRelease:
+ // cannot link against GC-only dylibs
+ for (InstallNameToReader::iterator it=fDylibMap.begin(); it != fDylibMap.end(); it++) {
+ if ( it->second->explicitlyLinked() ) {
+ if ( it->second->getObjCConstraint() == ObjectFile::Reader::kObjcGC )
+ throwf("this linkage unit uses Retain/Release. It cannot link against the GC-only dylib: %s", it->second->getPath());
+ }
+ }
+ break;
+ case ObjectFile::Reader::kObjcRetainReleaseOrGC:
+ // can link against GC or RR dylibs
+ break;
+ case ObjectFile::Reader::kObjcGC:
+ // cannot link against RR-only dylibs
+ for (InstallNameToReader::iterator it=fDylibMap.begin(); it != fDylibMap.end(); it++) {
+ if ( it->second->explicitlyLinked() ) {
+ if ( it->second->getObjCConstraint() == ObjectFile::Reader::kObjcRetainRelease )
+ throwf("this linkage unit requires GC. It cannot link against Retain/Release dylib: %s", it->second->getPath());
+ }
+ }
+ break;
+ }
+
+ // synthesize __OBJC __image_info atom if needed
+ if ( fCurrentObjCConstraint != ObjectFile::Reader::kObjcNone ) {
+ this->addAtom(fOutputFile->makeObjcInfoAtom(fCurrentObjCConstraint, fObjcReplacmentClasses));
+ }
+}
+
+
+static uint8_t pcRelKind(cpu_type_t arch)
+{
+ switch ( arch ) {
+ case CPU_TYPE_POWERPC:
+ return ppc::kPointerDiff32;
+ case CPU_TYPE_POWERPC64:
+ return ppc64::kPointerDiff32;
+ case CPU_TYPE_I386:
+ return x86::kPointerDiff;
+ case CPU_TYPE_X86_64:
+ return x86_64::kPointerDiff32;
+ case CPU_TYPE_ARM:
+ return arm::kPointerDiff;
+ }
+ throw "uknown architecture";
+}
+
+typedef uint8_t* (*oldcreatedof_func_t) (const char*, cpu_type_t, unsigned int, const char*[], const char*[], uint64_t offsetsInDOF[], size_t* size);
+typedef uint8_t* (*createdof_func_t)(cpu_type_t, unsigned int, const char*[], unsigned int, const char*[], const char*[], uint64_t offsetsInDOF[], size_t* size);
+
+
+void Linker::processDTrace()
+{
+ // only make __dof section in final linked images
+ if ( fOptions.outputKind() == Options::kObjectFile )
+ return;
+
+ // scan all atoms looking for dtrace probes
+ std::vector<DTraceProbeInfo> probeSites;
+ std::vector<DTraceProbeInfo> isEnabledSites;
+ std::map<const ObjectFile::Atom*,CStringSet> atomToDtraceTypes;
+ for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); ++it) {
+ ObjectFile::Atom* atom = *it;
+ std::vector<class ObjectFile::Reference*>& references = atom->getReferences();
+ for (std::vector<ObjectFile::Reference*>::iterator rit=references.begin(); rit != references.end(); ++rit) {
+ ObjectFile::Reference* ref = *rit;
+ if ( ref->getTargetBinding() == ObjectFile::Reference::kDontBind ) {
+ const char* probeName = ref->getTargetName();
+ if ( probeName != NULL ) {
+ uint32_t offsetInAtom = ref->getFixUpOffset();
+ if ( strncmp(probeName, "___dtrace_probe$", 16) == 0 )
+ probeSites.push_back(DTraceProbeInfo(atom, offsetInAtom, probeName));
+ else if ( strncmp(probeName, "___dtrace_isenabled$", 20) == 0 )
+ isEnabledSites.push_back(DTraceProbeInfo(atom, offsetInAtom, probeName));
+ else if ( strncmp(probeName, "___dtrace_", 10) == 0 )
+ atomToDtraceTypes[atom].insert(probeName);
+ }
+ }
+ }
+ }
+
+ // if no probes, we're done
+ if ( (probeSites.size() == 0) && (isEnabledSites.size() == 0) )
+ return;
+
+ // partition probes by provider name
+ // The symbol names looks like:
+ // "___dtrace_probe$" provider-name "$" probe-name [ "$"... ]
+ // "___dtrace_isenabled$" provider-name "$" probe-name [ "$"... ]
+ ProviderToProbes providerToProbes;
+ std::vector<DTraceProbeInfo> emptyList;
+ for(std::vector<DTraceProbeInfo>::iterator it = probeSites.begin(); it != probeSites.end(); ++it) {
+ // ignore probes in functions that were coalesed away rdar://problem/5628149
+ if ( fDeadAtoms.count((ObjectFile::Atom*)(it->atom)) == 0 ) {
+ const char* providerStart = &it->probeName[16];
+ const char* providerEnd = strchr(providerStart, '$');
+ if ( providerEnd != NULL ) {
+ char providerName[providerEnd-providerStart+1];
+ strlcpy(providerName, providerStart, providerEnd-providerStart+1);
+ ProviderToProbes::iterator pos = providerToProbes.find(providerName);
+ if ( pos == providerToProbes.end() ) {
+ const char* dup = strdup(providerName);
+ providerToProbes[dup] = emptyList;
+ }
+ providerToProbes[providerName].push_back(*it);
+ }
+ }
+ }
+ for(std::vector<DTraceProbeInfo>::iterator it = isEnabledSites.begin(); it != isEnabledSites.end(); ++it) {
+ // ignore probes in functions that were coalesed away rdar://problem/5628149
+ if ( fDeadAtoms.count((ObjectFile::Atom*)(it->atom)) == 0 ) {
+ const char* providerStart = &it->probeName[20];
+ const char* providerEnd = strchr(providerStart, '$');
+ if ( providerEnd != NULL ) {
+ char providerName[providerEnd-providerStart+1];
+ strlcpy(providerName, providerStart, providerEnd-providerStart+1);
+ ProviderToProbes::iterator pos = providerToProbes.find(providerName);
+ if ( pos == providerToProbes.end() ) {
+ const char* dup = strdup(providerName);
+ providerToProbes[dup] = emptyList;
+ }
+ providerToProbes[providerName].push_back(*it);
+ }
+ }
+ }
+
+ // create a DOF section for each provider
+ int dofIndex=1;
+ CStringSet sectionNamesUsed;
+ for(ProviderToProbes::iterator pit = providerToProbes.begin(); pit != providerToProbes.end(); ++pit, ++dofIndex) {
+ const char* providerName = pit->first;
+ const std::vector<DTraceProbeInfo>& probes = pit->second;
+
+ // open library and find dtrace_create_dof()
+ void* handle = dlopen("/usr/lib/libdtrace.dylib", RTLD_LAZY);
+ if ( handle == NULL )
+ throwf("couldn't dlopen() /usr/lib/libdtrace.dylib: %s", dlerror());
+ createdof_func_t pCreateDOF = (createdof_func_t)dlsym(handle, "dtrace_ld_create_dof");
+ if ( pCreateDOF == NULL )
+ throwf("couldn't find \"dtrace_ld_create_dof\" in /usr/lib/libdtrace.dylib: %s", dlerror());
+ // build list of typedefs/stability infos for this provider
+ CStringSet types;
+ for(std::vector<DTraceProbeInfo>::const_iterator it = probes.begin(); it != probes.end(); ++it) {
+ std::map<const ObjectFile::Atom*,CStringSet>::iterator pos = atomToDtraceTypes.find(it->atom);
+ if ( pos != atomToDtraceTypes.end() ) {
+ for(CStringSet::iterator sit = pos->second.begin(); sit != pos->second.end(); ++sit) {
+ const char* providerStart = strchr(*sit, '$')+1;
+ const char* providerEnd = strchr(providerStart, '$');
+ if ( providerEnd != NULL ) {
+ char aProviderName[providerEnd-providerStart+1];
+ strlcpy(aProviderName, providerStart, providerEnd-providerStart+1);
+ if ( strcmp(aProviderName, providerName) == 0 )
+ types.insert(*sit);
+ }
+ }
+ }
+ }
+ int typeCount = types.size();
+ const char* typeNames[typeCount];
+ //fprintf(stderr, "types for %s:\n", providerName);
+ uint32_t index = 0;
+ for(CStringSet::iterator it = types.begin(); it != types.end(); ++it) {
+ typeNames[index] = *it;
+ //fprintf(stderr, "\t%s\n", *it);
+ ++index;
+ }
+
+ // build list of probe/isenabled sites
+ const uint32_t probeCount = probes.size();
+ const char* probeNames[probeCount];
+ const char* funtionNames[probeCount];
+ uint64_t offsetsInDOF[probeCount];
+ index = 0;
+ for(std::vector<DTraceProbeInfo>::const_iterator it = probes.begin(); it != probes.end(); ++it) {
+ probeNames[index] = it->probeName;
+ funtionNames[index] = it->atom->getName();
+ offsetsInDOF[index] = 0;
+ ++index;
+ }
+ //fprintf(stderr, "calling libtrace to create DOF\n");
+ //for(uint32_t i=0; i < probeCount; ++i)
+ // fprintf(stderr, " [%u]\t %s\t%s\n", i, probeNames[i], funtionNames[i]);
+ // call dtrace library to create DOF section
+ size_t dofSectionSize;
+ uint8_t* p = (*pCreateDOF)(fArchitecture, typeCount, typeNames, probeCount, probeNames, funtionNames, offsetsInDOF, &dofSectionSize);
+ if ( p != NULL ) {
+ char sectionName[18];
+ strcpy(sectionName, "__dof_");
+ strlcpy(§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[i]=%0llX > dofSectionSize=%0lX\n", i, offset, dofSectionSize);
+ reader->addSectionReference(pcRelKind(fArchitecture), offset, probes[i].atom, probes[i].offset, reader->getAtoms()[0], 0);
+ }
+ this->addAtoms(reader->getAtoms());
+ }
+ else {
+ throw "error creating dtrace DOF section";
+ }
+ }
+}
+
+
+static bool matchesObjectFile(ObjectFile::Atom* atom, const char* objectFileLeafName)
+{
+ if ( objectFileLeafName == NULL )
+ return true;
+ const char* atomFullPath = atom->getFile()->getPath();
+ const char* lastSlash = strrchr(atomFullPath, '/');
+ if ( lastSlash != NULL ) {
+ if ( strcmp(&lastSlash[1], objectFileLeafName) == 0 )
+ return true;
+ }
+ else {
+ if ( strcmp(atomFullPath, objectFileLeafName) == 0 )
+ return true;
+ }
+ return false;
+}
+
+
+static bool usesAnonymousNamespace(const char* symbol)
+{
+ return ( (strncmp(symbol, "__Z", 3) == 0) && (strstr(symbol, "_GLOBAL__N_") != NULL) );
+}
+
+
+//
+// convert:
+// __ZN20_GLOBAL__N__Z5main2v3barEv => _ZN-3barEv
+// __ZN37_GLOBAL__N_main.cxx_00000000_493A01A33barEv => _ZN-3barEv
+//
+static void canonicalizeAnonymousName(const char* inSymbol, char outSymbol[])
+{
+ const char* globPtr = strstr(inSymbol, "_GLOBAL__N_");
+ while ( isdigit(*(--globPtr)) )
+ ; // loop
+ char* endptr;
+ unsigned long length = strtoul(globPtr+1, &endptr, 10);
+ const char* globEndPtr = endptr + length;
+ int startLen = globPtr-inSymbol+1;
+ memcpy(outSymbol, inSymbol, startLen);
+ outSymbol[startLen] = '-';
+ strcpy(&outSymbol[startLen+1], globEndPtr);
+}
+
+
+ObjectFile::Atom* Linker::findAtom(const Options::OrderedSymbol& orderedSymbol)
+{
+ ObjectFile::Atom* atom = fGlobalSymbolTable.find(orderedSymbol.symbolName);
+ if ( atom != NULL ) {
+ if ( matchesObjectFile(atom, orderedSymbol.objectFileName) )
+ return atom;
+ }
+ else {
+ // slow case. The requested symbol is not in symbol table, so might be static function
+ static SymbolTable::Mapper hashTableOfTranslationUnitScopedSymbols;
+ static SymbolTable::Mapper hashTableOfSymbolsWithAnonymousNamespace;
+ static bool built = false;
+ // build a hash_map the first time
+ if ( !built ) {
+ for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
+ atom = *it;
+ const char* name = atom->getName();
+ if ( name != NULL) {
+ if ( usesAnonymousNamespace(name) ) {
+ // symbol that uses anonymous namespace
+ char canonicalName[strlen(name)+2];
+ canonicalizeAnonymousName(name, canonicalName);
+ const char* hashName = strdup(canonicalName);
+ SymbolTable::Mapper::iterator pos = hashTableOfSymbolsWithAnonymousNamespace.find(hashName);
+ if ( pos == hashTableOfSymbolsWithAnonymousNamespace.end() )
+ hashTableOfSymbolsWithAnonymousNamespace[hashName] = atom;
+ else
+ hashTableOfSymbolsWithAnonymousNamespace[hashName] = NULL; // collision, denote with NULL
+ }
+ else if ( atom->getScope() == ObjectFile::Atom::scopeTranslationUnit ) {
+ // static function or data
+ SymbolTable::Mapper::iterator pos = hashTableOfTranslationUnitScopedSymbols.find(name);
+ if ( pos == hashTableOfTranslationUnitScopedSymbols.end() )
+ hashTableOfTranslationUnitScopedSymbols[name] = atom;
+ else
+ hashTableOfTranslationUnitScopedSymbols[name] = NULL; // collision, denote with NULL
+ }
+ }
+ }
+ //fprintf(stderr, "built hash table of %lu static functions\n", hashTableOfTranslationUnitScopedSymbols.size());
+ built = true;
+ }
+
+ // look for name in hashTableOfTranslationUnitScopedSymbols
+ SymbolTable::Mapper::iterator pos = hashTableOfTranslationUnitScopedSymbols.find(orderedSymbol.symbolName);
+ if ( pos != hashTableOfTranslationUnitScopedSymbols.end() ) {
+ if ( (pos->second != NULL) && matchesObjectFile(pos->second, orderedSymbol.objectFileName) ) {
+ //fprintf(stderr, "found %s in hash table\n", orderedSymbol.symbolName);
+ return pos->second;
+ }
+ if ( pos->second == NULL )
+ // name is in hash table, but atom is NULL, so that means there are duplicates, so we use super slow way
+ for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
+ atom = *it;
+ if ( atom->getScope() == ObjectFile::Atom::scopeTranslationUnit ) {
+ const char* name = atom->getName();
+ if ( (name != NULL) && (strcmp(name, orderedSymbol.symbolName) == 0) ) {
+ if ( matchesObjectFile(atom, orderedSymbol.objectFileName) ) {
+ if ( fOptions.printOrderFileStatistics() )
+ warning("%s specified in order_file but it exists in multiple .o files. "
+ "Prefix symbol with .o filename in order_file to disambiguate", orderedSymbol.symbolName);
+ return atom;
+ }
+ }
+ }
+ }
+ }
+
+ // look for name in hashTableOfSymbolsWithAnonymousNamespace
+ if ( usesAnonymousNamespace(orderedSymbol.symbolName) ) {
+ // symbol that uses anonymous namespace
+ char canonicalName[strlen(orderedSymbol.symbolName)+2];
+ canonicalizeAnonymousName(orderedSymbol.symbolName, canonicalName);
+ SymbolTable::Mapper::iterator pos = hashTableOfSymbolsWithAnonymousNamespace.find(canonicalName);
+ if ( pos != hashTableOfSymbolsWithAnonymousNamespace.end() ) {
+ if ( (pos->second != NULL) && matchesObjectFile(pos->second, orderedSymbol.objectFileName) ) {
+ //fprintf(stderr, "found %s in anonymous namespace hash table\n", canonicalName);
+ return pos->second;
+ }
+ if ( pos->second == NULL )
+ // name is in hash table, but atom is NULL, so that means there are duplicates, so we use super slow way
+ for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
+ atom = *it;
+ const char* name = atom->getName();
+ if ( (name != NULL) && usesAnonymousNamespace(name) ) {
+ char canonicalAtomName[strlen(name)+2];
+ canonicalizeAnonymousName(name, canonicalAtomName);
+ if ( strcmp(canonicalAtomName, canonicalName) == 0 ) {
+ if ( matchesObjectFile(atom, orderedSymbol.objectFileName) ) {
+ if ( fOptions.printOrderFileStatistics() )
+ warning("%s specified in order_file but it exists in multiple .o files. "
+ "Prefix symbol with .o filename in order_file to disambiguate", orderedSymbol.symbolName);
+ return atom;
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ return NULL;
+}
+
+
+void Linker::sortSections()
+{
+ Section::assignIndexes();
+}
+
+
+//
+// Linker::sortAtoms()
+//
+// The purpose of this method is to take the graph of all Atoms and produce an ordered
+// sequence of atoms. The constraints are that: 1) all Atoms of the same Segment must
+// be contiguous, 2) all Atoms of the same Section must be contigous, 3) Atoms specified
+// in an order_file are seqenced as in the order_file and before Atoms not specified,
+// 4) Atoms in the same section from the same .o file should be contiguous and sequenced
+// in the same order they were in the .o file, 5) Atoms in the same Section but which came
+// from different .o files should be sequenced in the same order that the .o files
+// were passed to the linker (i.e. command line order).
+//
+// The way this is implemented is that the linker passes a "base ordinal" to each Reader
+// as it is constructed. The reader should construct it Atoms so that calling getOrdinal()
+// on its atoms returns a contiguous range of values starting at the base ordinal. Then
+// sorting is just sorting by section, then by ordinal.
+//
+// If an order_file is specified, it gets more complicated. First, an override-ordinal map
+// is created. It causes the sort routine to ignore the value returned by getOrdinal() and
+// use the override value instead. Next some Atoms must be layed out consecutively
+// (e.g. hand written assembly that does not end with return, but rather falls into
+// the next label). This is modeled in Readers via a "kFollowOn" reference. The use of
+// kFollowOn refernces produces "clusters" of atoms that must stay together.
+// If an order_file tries to move one atom, it may need to move a whole cluster. The
+// algorithm to do this models clusters using two maps. The "starts" maps maps any
+// atom in a cluster to the first Atom in the cluster. The "nexts" maps an Atom in a
+// cluster to the next Atom in the cluster. With this in place, while processing an
+// order_file, if any entry is in a cluster (in "starts" map), then the entire cluster is
+// given ordinal overrides.
+//
+void Linker::sortAtoms()
+{
+ fStartSortTime = mach_absolute_time();
+ // if -order_file is used, build map of atom ordinal overrides
+ std::map<const ObjectFile::Atom*, uint32_t>* ordinalOverrideMap = NULL;
+ std::map<const ObjectFile::Atom*, uint32_t> theOrdinalOverrideMap;
+ const bool log = false;
+ if ( fOptions.orderedSymbols().size() != 0 ) {
+ // first make a pass to find all follow-on references and build start/next maps
+ // which are a way to represent clusters of atoms that must layout together
+ std::map<const ObjectFile::Atom*, const ObjectFile::Atom*> followOnStarts;
+ std::map<const ObjectFile::Atom*, const ObjectFile::Atom*> followOnNexts;
+ for (std::vector<ObjectFile::Atom*>::iterator ait=fAllAtoms.begin(); ait != fAllAtoms.end(); ait++) {
+ ObjectFile::Atom* atom = *ait;
+ std::vector<class ObjectFile::Reference*>& references = atom->getReferences();
+ for (std::vector<ObjectFile::Reference*>::iterator rit=references.begin(); rit != references.end(); rit++) {
+ ObjectFile::Reference* ref = *rit;
+ if ( ref->getKind() == 1 ) { // FIX FIX
+ ObjectFile::Atom* targetAtom = &ref->getTarget();
+ if ( log ) fprintf(stderr, "ref %s -> %s", atom->getDisplayName(), targetAtom->getDisplayName());
+ std::map<const ObjectFile::Atom*, const ObjectFile::Atom*>::iterator startFrom = followOnStarts.find(atom);
+ std::map<const ObjectFile::Atom*, const ObjectFile::Atom*>::iterator startTo = followOnStarts.find(targetAtom);
+ if ( (startFrom == followOnStarts.end()) && (startTo == followOnStarts.end()) ) {
+ // this is first time we've seen either atom, make simple cluster of the two
+ if ( log ) fprintf(stderr, " new cluster\n");
+ followOnStarts[atom] = atom;
+ followOnStarts[targetAtom] = atom;
+ followOnNexts[atom] = targetAtom;
+ followOnNexts[targetAtom] = NULL;
+ }
+ else if ( (startFrom != followOnStarts.end()) && (startTo == followOnStarts.end()) && (followOnNexts[atom] == NULL) ) {
+ // atom is at end of an existing cluster, so append target to end of cluster
+ if ( log ) fprintf(stderr, " end of cluster starting with %s\n", followOnStarts[atom]->getDisplayName());
+ followOnNexts[atom] = targetAtom;
+ followOnNexts[targetAtom] = NULL;
+ followOnStarts[targetAtom] = followOnStarts[atom];
+ }
+ else {
+ // gerneral case of inserting into an existing cluster
+ if ( followOnNexts[atom] != NULL ) {
+ // an atom with two follow-ons is illegal
+ warning("can't order %s because both %s and %s must follow it",
+ atom->getDisplayName(), targetAtom->getDisplayName(), followOnNexts[atom]->getDisplayName());
+ }
+ else {
+ // there already exists an atom that says target must be its follow-on
+ const ObjectFile::Atom* originalStart = startTo->second;
+ const ObjectFile::Atom* originalPrevious = originalStart;
+ while ( followOnNexts[originalPrevious] != targetAtom )
+ originalPrevious = followOnNexts[originalPrevious];
+ bool otherIsAlias = (originalPrevious->getSize() == 0);
+ bool thisIsAlias = (atom->getSize() == 0);
+ if ( !otherIsAlias && !thisIsAlias ) {
+ warning("can't order %s because both %s and %s must preceed it",
+ targetAtom->getDisplayName(), originalPrevious->getDisplayName(), atom->getDisplayName());
+ }
+ else if ( otherIsAlias ) {
+ if ( originalPrevious == originalStart ) {
+ // other is alias at start of cluster, make this the new start of cluster
+ if ( log ) fprintf(stderr, " becomes new start of cluster previous starting with %s\n", originalStart->getDisplayName());
+ followOnNexts[atom] = originalPrevious;
+ for(const ObjectFile::Atom* nextAtom = atom; nextAtom != NULL; nextAtom = followOnNexts[nextAtom])
+ followOnStarts[nextAtom] = atom;
+ }
+ else {
+ // other is alias in middle of cluster, insert new atom before it
+ if ( log ) fprintf(stderr, " insert into cluster starting with %s before alias %s\n", originalStart->getDisplayName(), originalPrevious->getDisplayName());
+ followOnStarts[atom] = originalStart;
+ followOnNexts[atom] = originalPrevious;
+ for(const ObjectFile::Atom* a = originalStart; a != NULL; a = followOnNexts[a]) {
+ if ( followOnNexts[a] == originalPrevious ) {
+ followOnNexts[a] = atom;
+ break;
+ }
+ }
+ }
+ }
+ else {
+ // this is alias, so it can go inbetween originalPrevious and targetAtom
+ if ( log ) fprintf(stderr, " insert into cluster starting with %s after %s\n", originalStart->getDisplayName(), originalPrevious->getDisplayName());
+ followOnStarts[atom] = originalStart;
+ followOnNexts[atom] = followOnNexts[originalPrevious];
+ followOnNexts[originalPrevious] = atom;
+ }
+ }
+ }
+ }
+ }
+ }
+
+ if ( log ) {
+ for(std::map<const ObjectFile::Atom*, const ObjectFile::Atom*>::iterator it = followOnStarts.begin(); it != followOnStarts.end(); ++it)
+ fprintf(stderr, "start %s -> %s\n", it->first->getDisplayName(), it->second->getDisplayName());
+
+ for(std::map<const ObjectFile::Atom*, const ObjectFile::Atom*>::iterator it = followOnNexts.begin(); it != followOnNexts.end(); ++it)
+ fprintf(stderr, "next %s -> %s\n", it->first->getDisplayName(), (it->second != NULL) ? it->second->getDisplayName() : "null");
+ }
+
+ // with the start/next maps of follow-on atoms we can process the order file and produce override ordinals
+ ordinalOverrideMap = &theOrdinalOverrideMap;
+ uint32_t index = 0;
+ uint32_t matchCount = 0;
+ std::vector<Options::OrderedSymbol>& orderedSymbols = fOptions.orderedSymbols();
+ for(std::vector<Options::OrderedSymbol>::iterator it = orderedSymbols.begin(); it != orderedSymbols.end(); ++it) {
+ ObjectFile::Atom* atom = this->findAtom(*it);
+ if ( atom != NULL ) {
+ std::map<const ObjectFile::Atom*, const ObjectFile::Atom*>::iterator start = followOnStarts.find(atom);
+ if ( start != followOnStarts.end() ) {
+ // this symbol for the order file corresponds to an atom that is in a cluster that must lay out together
+ for(const ObjectFile::Atom* nextAtom = start->second; nextAtom != NULL; nextAtom = followOnNexts[nextAtom]) {
+ std::map<const ObjectFile::Atom*, uint32_t>::iterator pos = theOrdinalOverrideMap.find(nextAtom);
+ if ( pos == theOrdinalOverrideMap.end() ) {
+ theOrdinalOverrideMap[nextAtom] = index++;
+ if (log ) fprintf(stderr, "override ordinal %u assigned to %s in cluster from %s\n", index, nextAtom->getDisplayName(), nextAtom->getFile()->getPath());
+ }
+ else {
+ if (log ) fprintf(stderr, "could not order %s as %u because it was already laid out earlier by %s as %u\n",
+ atom->getDisplayName(), index, followOnStarts[atom]->getDisplayName(), theOrdinalOverrideMap[atom] );
+ }
+ }
+ }
+ else {
+ theOrdinalOverrideMap[atom] = index;
+ if (log ) fprintf(stderr, "override ordinal %u assigned to %s from %s\n", index, atom->getDisplayName(), atom->getFile()->getPath());
+ }
+ }
+ else {
+ ++matchCount;
+ //fprintf(stderr, "can't find match for order_file entry %s/%s\n", it->objectFileName, it->symbolName);
+ }
+ ++index;
+ }
+ if ( fOptions.printOrderFileStatistics() && (fOptions.orderedSymbols().size() != matchCount) ) {
+ warning("only %u out of %lu order_file symbols were applicable", matchCount, fOptions.orderedSymbols().size() );
+ }
+ }
+
+ // sort atoms
+ std::sort(fAllAtoms.begin(), fAllAtoms.end(), Linker::AtomSorter(ordinalOverrideMap, fInitializerAtoms, fTerminatorAtoms));
+
+ //fprintf(stderr, "Sorted atoms:\n");
+ //for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
+ // fprintf(stderr, "\t%p, %u %s\t%s\n", (*it)->getSection(), (*it)->getSection()->getIndex(), (*it)->getDisplayName(), (*it)->getFile()->getPath());
+ //}
+}
+
+
+// make sure given addresses are within reach of branches, etc
+void Linker::tweakLayout()
+{
+ // > 2GB images need their large zero fill atoms sorted to the end to keep access with +/- 2GB
+ if ( fTotalSize > 0x7F000000 ) {
+ fBiggerThanTwoGigOutput = true;
+
+ if ( (fTotalSize-fTotalZeroFillSize) > 0x7F000000 )
+ throwf("total output size exceeds 2GB (%lldMB)", (fTotalSize-fTotalZeroFillSize)/(1024*1024));
+
+ // move very large (>1MB) zero fill atoms to a new section at very end of __DATA segment
+ Section* hugeZeroFills = Section::find("__huge", "__DATA", true);
+ for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
+ ObjectFile::Atom* atom = *it;
+ if ( atom->isZeroFill() && (atom->getSize() > 1024*1024) && (strcmp(atom->getSegment().getName(), "__DATA") == 0) )
+ atom->setSection(hugeZeroFills);
+ }
+ }
+
+ // move all initializers to start of __text section
+ if ( fOptions.readerOptions().fAutoOrderInitializers ) {
+ // move -init function to front of __text
+ if ( fOptions.initFunctionName() != NULL ) {
+ ObjectFile::Atom* initAtom = fGlobalSymbolTable.find(fOptions.initFunctionName());
+ if ( initAtom == NULL )
+ throwf("could not find -init function: \"%s\"", fOptions.initFunctionName());
+ moveToFrontOfSection(initAtom);
+ }
+
+ // move all functions pointed to by __mod_init_func section to front of __text
+ Section* initSection = Section::find("__mod_init_func", "__DATA", false, false);
+ if ( initSection != NULL ) {
+ for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); ++it) {
+ if ( (*it)->getSection() == initSection ) {
+ std::vector<class ObjectFile::Reference*>& references = (*it)->getReferences();
+ if ( references.size() == 1 )
+ moveToFrontOfSection(&(references[0]->getTarget()));
+ }
+ }
+ }
+ }
+
+ // move atoms with relocations to start of __DATA,__data section
+ // <rdar://problem/6061558> linker should order __DATA segment to reduce dyld dirtied pages
+ if ( fOptions.orderData() ) {
+ bool slideable = false;
+ switch ( fOptions.outputKind() ) {
+ case Options::kDynamicExecutable:
+ case Options::kStaticExecutable:
+ case Options::kDyld:
+ case Options::kPreload:
+ case Options::kObjectFile:
+ case Options::kKextBundle:
+ slideable = false;
+ break;
+ case Options::kDynamicLibrary:
+ case Options::kDynamicBundle:
+ slideable = true;
+ break;
+ }
+ const bool hasPreferredLoadAddress = (fOptions.baseAddress() != 0);
+ Section* dataSection = Section::find("__data", "__DATA", false, false);
+ if ( dataSection != NULL ) {
+ for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); ++it) {
+ ObjectFile::Atom* dataAtom = *it;
+ if ( dataAtom->getSection() == dataSection ) {
+ std::vector<class ObjectFile::Reference*>& references = dataAtom->getReferences();
+ if ( references.size() > 0 ) {
+ if ( slideable && !hasPreferredLoadAddress ) {
+ // in a slidable image dyld will need to rebase and bind so any references will need runtime fixups
+ // if image has preferred base address, assume it will load there and not rebase
+ moveToFrontOfSection(dataAtom);
+ }
+ else {
+ // in a non-slideable image, dyld will only do binding, so only references to
+ // symbols in another dylib will need runtime fixups
+ //fprintf(stderr, "reference from atom %s\n", dataAtom->getDisplayName());
+ for (std::vector<ObjectFile::Reference*>::iterator rit=references.begin(); rit != references.end(); rit++) {
+ ObjectFile::Reference* reference = *rit;
+ //fprintf(stderr, "\t%d %s\n", reference->getTarget().getDefinitionKind(), reference->getTarget().getDisplayName());
+ if ( (reference->getTarget().getDefinitionKind() == ObjectFile::Atom::kExternalDefinition)
+ || (reference->getTarget().getDefinitionKind() == ObjectFile::Atom::kExternalWeakDefinition) ) {
+ moveToFrontOfSection(dataAtom);
+ break;
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+
+}
+
+
+void Linker::writeDotOutput()
+{
+ const char* dotOutFilePath = fOptions.dotOutputFile();
+ if ( dotOutFilePath != NULL ) {
+ FILE* out = fopen(dotOutFilePath, "w");
+ if ( out != NULL ) {
+ // print header
+ fprintf(out, "digraph dg\n{\n");
+ fprintf(out, "\tconcentrate = true;\n");
+ fprintf(out, "\trankdir = LR;\n");
+
+ // print each atom as a node
+ for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
+ ObjectFile::Atom* atom = *it;
+ if ( atom->getFile() != fOutputFile ) {
+ const char* name = atom->getDisplayName();
+ if ( (atom->getDefinitionKind() == ObjectFile::Atom::kExternalDefinition)
+ || (atom->getDefinitionKind() == ObjectFile::Atom::kExternalWeakDefinition) ) {
+ fprintf(out, "\taddr%p [ shape = plaintext, label = \"%s\" ];\n", atom, name);
+ }
+ else if ( strcmp(atom->getSectionName(), "__cstring") == 0 ) {
+ char cstring[atom->getSize()+2];
+ atom->copyRawContent((uint8_t*)cstring);
+ fprintf(out, "\taddr%p [ label = \"string: '", atom);
+ for (const char* s=cstring; *s != '\0'; ++s) {
+ if ( *s == '\n' )
+ fprintf(out, "\\\\n");
+ else
+ fputc(*s, out);
+ }
+ fprintf(out, "'\" ];\n");
+ }
+ else {
+ fprintf(out, "\taddr%p [ label = \"%s\" ];\n", atom, name);
+ }
+ }
+ }
+ fprintf(out, "\n");
+
+ // print each reference as an edge
+ for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
+ ObjectFile::Atom* fromAtom = *it;
+ if ( fromAtom->getFile() != fOutputFile ) {
+ std::vector<ObjectFile::Reference*>& references = fromAtom->getReferences();
+ std::set<ObjectFile::Atom*> seenTargets;
+ for (std::vector<ObjectFile::Reference*>::iterator rit=references.begin(); rit != references.end(); rit++) {
+ ObjectFile::Reference* reference = *rit;
+ ObjectFile::Atom* toAtom = &(reference->getTarget());
+ if ( seenTargets.count(toAtom) == 0 ) {
+ seenTargets.insert(toAtom);
+ fprintf(out, "\taddr%p -> addr%p;\n", fromAtom, toAtom);
+ }
+ }
+ }
+ }
+ fprintf(out, "\n");
+
+ // push all imports to bottom of graph
+ fprintf(out, "{ rank = same; ");
+ for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
+ ObjectFile::Atom* atom = *it;
+ if ( atom->getFile() != fOutputFile )
+ if ( (atom->getDefinitionKind() == ObjectFile::Atom::kExternalDefinition)
+ || (atom->getDefinitionKind() == ObjectFile::Atom::kExternalWeakDefinition) ) {
+ fprintf(out, "addr%p; ", atom);
+ }
+ }
+ fprintf(out, "};\n ");
+
+ // print footer
+ fprintf(out, "}\n");
+ fclose(out);
+ }
+ else {
+ warning("could not write dot output file: %s", dotOutFilePath);
+ }
+ }
+}
+
+ObjectFile::Atom* Linker::entryPoint(bool orInit)
+{
+ // if main executable, find entry point atom
+ ObjectFile::Atom* entryPoint = NULL;
+ switch ( fOptions.outputKind() ) {
+ case Options::kDynamicExecutable:
+ case Options::kStaticExecutable:
+ case Options::kDyld:
+ case Options::kPreload:
+ entryPoint = fGlobalSymbolTable.find(fOptions.entryName());
+ if ( entryPoint == NULL ) {
+ throwf("could not find entry point \"%s\" (perhaps missing crt1.o)", fOptions.entryName());
+ }
+ break;
+ case Options::kDynamicLibrary:
+ if ( orInit && (fOptions.initFunctionName() != NULL) ) {
+ entryPoint = fGlobalSymbolTable.find(fOptions.initFunctionName());
+ if ( entryPoint == NULL ) {
+ throwf("could not find -init function: \"%s\"", fOptions.initFunctionName());
+ }
+ }
+ break;
+ case Options::kObjectFile:
+ case Options::kDynamicBundle:
+ case Options::kKextBundle:
+ entryPoint = NULL;
+ break;
+ }
+ return entryPoint;
+}
+
+ObjectFile::Atom* Linker::dyldClassicHelper()
+{
+ if ( fOptions.makeClassicDyldInfo() )
+ return fGlobalSymbolTable.find("dyld_stub_binding_helper");
+ else
+ return NULL;
+}
+
+ObjectFile::Atom* Linker::dyldCompressedHelper()
+{
+ if ( fOptions.makeCompressedDyldInfo() ) {
+ // dyld_stub_binder is in libSystem.B.dylib
+ ObjectFile::Atom* atom = fGlobalSymbolTable.find("dyld_stub_binder");
+ if ( atom == NULL ) {
+ this->addJustInTimeAtoms("dyld_stub_binder", true, false, true);
+ }
+ atom = fGlobalSymbolTable.find("dyld_stub_binder");
+ return atom;
+ }
+ else
+ return NULL;
+}
+
+ObjectFile::Atom* Linker::dyldLazyLibraryHelper()
+{
+ return fGlobalSymbolTable.find("dyld_lazy_dylib_stub_binding_helper");
+}
+
+const char* Linker::assureFullPath(const char* path)
+{
+ if ( path[0] == '/' )
+ return path;
+ char cwdbuff[MAXPATHLEN];
+ if ( getcwd(cwdbuff, MAXPATHLEN) != NULL ) {
+ char* result;
+ asprintf(&result, "%s/%s", cwdbuff, path);
+ if ( result != NULL )
+ return result;
+ }
+ return path;
+}
+
+
+//
+// The stab strings are of the form:
+// <name> ':' <type-code> <number-pari>
+// but the <name> contain a colon.
+// For C++ <name> may contain a double colon (e.g. std::string:f(0,1) )
+// For Objective-C name may contain a colon instead square bracket (e.g. [Foo doit:]:f(0,1) )
+//
+const char* Linker::truncateStabString(const char* str)
+{
+ enum { start, inObjc } state = start;
+ for (const char* s = str; *s != 0; ++s) {
+ char c = *s;
+ switch (state) {
+ case start:
+ if ( c == '[' ) {
+ state = inObjc;
+ }
+ else {
+ if ( c == ':' ) {
+ if ( s[1] == ':' ) {
+ ++s;
+ }
+ else {
+ // found colon
+ // Duplicate strndup behavior here.
+ int trunStrLen = s-str+2;
+ char* temp = new char[trunStrLen+1];
+ memcpy(temp, str, trunStrLen);
+ temp[trunStrLen] = '\0';
+ return temp;
+ }
+ }
+ }
+ break;
+ case inObjc:
+ if ( c == ']' ) {
+ state = start;
+ }
+ break;
+ }
+ }
+ // malformed
+ return str;
+}
+
+
+bool Linker::minimizeStab(ObjectFile::Reader::Stab& stab)
+{
+ switch(stab.type){
+ case N_GSYM:
+ case N_STSYM:
+ case N_LCSYM:
+ case N_FUN:
+ // these all need truncated strings
+ stab.string = truncateStabString(stab.string);
+ return true;
+ case N_SO:
+ case N_OSO:
+ case N_OPT:
+ case N_SOL:
+ // these are included in the minimal stabs, but they keep their full string
+ return true;
+ default:
+ return false;
+ }
+}
+
+
+struct HeaderRange {
+ std::vector<ObjectFile::Reader::Stab>::iterator begin;
+ std::vector<ObjectFile::Reader::Stab>::iterator end;
+ int parentRangeIndex;
+ uint32_t sum;
+ bool sumPrecomputed;
+ bool useEXCL;
+ bool cannotEXCL; // because of SLINE, etc stabs
+};
+
+
+typedef __gnu_cxx::hash_map<const char*, std::vector<uint32_t>, __gnu_cxx::hash<const char*>, CStringEquals> PathToSums;
+
+// hash table that maps header path to a vector of known checksums for that path
+static PathToSums sKnownBINCLs;
+
+
+void Linker::collectStabs(ObjectFile::Reader* reader, std::map<const class ObjectFile::Atom*, uint32_t>& atomOrdinals)
+{
+ const bool log = false;
+ bool minimal = ( fOptions.readerOptions().fDebugInfoStripping == ObjectFile::ReaderOptions::kDebugInfoMinimal );
+ std::vector<class ObjectFile::Reader::Stab>* readerStabs = reader->getStabs();
+ if ( readerStabs == NULL )
+ return;
+
+ if ( log ) fprintf(stderr, "processesing %lu stabs for %s\n", readerStabs->size(), reader->getPath());
+ std::vector<HeaderRange> ranges;
+ int curRangeIndex = -1;
+ int count = 0;
+ ObjectFile::Atom* atomWithLowestOrdinal = NULL;
+ ObjectFile::Atom* atomWithHighestOrdinal = NULL;
+ uint32_t highestOrdinal = 0;
+ uint32_t lowestOrdinal = UINT_MAX;
+ std::vector<std::pair<ObjectFile::Atom*,ObjectFile::Atom*> > soRanges;
+ // 1) find all (possibly nested) BINCL/EINCL ranges and their checksums
+ // 2) find all SO/SO ranges and the first/last atom own by a FUN stab therein
+ for(std::vector<class ObjectFile::Reader::Stab>::iterator it=readerStabs->begin(); it != readerStabs->end(); ++it) {
+ ++count;
+ switch ( it->type ) {
+ case N_BINCL:
+ {
+ HeaderRange range;
+ range.begin = it;
+ range.end = readerStabs->end();
+ range.parentRangeIndex = curRangeIndex;
+ range.sum = it->value;
+ range.sumPrecomputed = (range.sum != 0);
+ range.useEXCL = false;
+ range.cannotEXCL = false;
+ curRangeIndex = ranges.size();
+ if ( log ) fprintf(stderr, "[%d]BINCL %s\n", curRangeIndex, it->string);
+ ranges.push_back(range);
+ }
+ break;
+ case N_EINCL:
+ if ( curRangeIndex == -1 ) {
+ warning("EINCL missing BINCL in %s", reader->getPath());
+ }
+ else {
+ ranges[curRangeIndex].end = it+1;
+ if ( log ) fprintf(stderr, "[%d->%d]EINCL %s\n", curRangeIndex, ranges[curRangeIndex].parentRangeIndex, it->string);
+ curRangeIndex = ranges[curRangeIndex].parentRangeIndex;
+ }
+ break;
+ case N_FUN:
+ {
+ std::map<const class ObjectFile::Atom*, uint32_t>::iterator pos = atomOrdinals.find(it->atom);
+ if ( pos != atomOrdinals.end() ) {
+ uint32_t ordinal = pos->second;
+ if ( ordinal > highestOrdinal ) {
+ highestOrdinal = ordinal;
+ atomWithHighestOrdinal = it->atom;
+ }
+ if ( ordinal < lowestOrdinal ) {
+ lowestOrdinal = ordinal;
+ atomWithLowestOrdinal = it->atom;
+ }
+ }
+ }
+ // fall through
+ case N_BNSYM:
+ case N_ENSYM:
+ case N_LBRAC:
+ case N_RBRAC:
+ case N_SLINE:
+ case N_STSYM:
+ case N_LCSYM:
+ if ( curRangeIndex != -1 ) {
+ ranges[curRangeIndex].cannotEXCL = true;
+ if ( fOptions.warnStabs() )
+ warning("cannot do BINCL/EINCL optimzation because of stabs kinds in %s for %s\n", ranges[curRangeIndex].begin->string, reader->getPath());
+ }
+ break;
+ case N_SO:
+ if ( (it->string != NULL) && (strlen(it->string) > 0) ) {
+ // start SO, reset hi/low FUN tracking
+ atomWithLowestOrdinal = NULL;
+ atomWithHighestOrdinal = NULL;
+ highestOrdinal = 0;
+ lowestOrdinal = UINT_MAX;
+ }
+ else {
+ // end SO, record hi/low atoms for this SO range
+ soRanges.push_back(std::make_pair<ObjectFile::Atom*,ObjectFile::Atom*>(atomWithLowestOrdinal, atomWithHighestOrdinal));
+ }
+ // fall through
+ default:
+ if ( curRangeIndex != -1 ) {
+ if ( ! ranges[curRangeIndex].sumPrecomputed ) {
+ uint32_t sum = 0;
+ const char* s = it->string;
+ char c;
+ while ( (c = *s++) != 0 ) {
+ sum += c;
+ // don't checkusm first number (file index) after open paren in string
+ if ( c == '(' ) {
+ while(isdigit(*s))
+ ++s;
+ }
+ }
+ ranges[curRangeIndex].sum += sum;
+ }
+ }
+
+ }
+ }
+ if ( log ) fprintf(stderr, "processesed %d stabs for %s\n", count, reader->getPath());
+ if ( curRangeIndex != -1 )
+ warning("BINCL (%s) missing EINCL in %s", ranges[curRangeIndex].begin->string, reader->getPath());
+
+ // if no BINCLs
+ if ( ranges.size() == 0 ) {
+ unsigned int soIndex = 0;
+ for(std::vector<ObjectFile::Reader::Stab>::iterator it=readerStabs->begin(); it != readerStabs->end(); ++it) {
+ // copy minimal or all stabs
+ ObjectFile::Reader::Stab stab = *it;
+ if ( !minimal || minimizeStab(stab) ) {
+ if ( stab.type == N_SO ) {
+ if ( soIndex < soRanges.size() ) {
+ if ( (stab.string != NULL) && (strlen(stab.string) > 0) ) {
+ // starting SO is associated with first atom
+ stab.atom = soRanges[soIndex].first;
+ }
+ else {
+ // ending SO is associated with last atom
+ stab.atom = soRanges[soIndex].second;
+ ++soIndex;
+ }
+ }
+ }
+ fStabs.push_back(stab);
+ }
+ }
+ return;
+ }
+
+ //fprintf(stderr, "BINCL/EINCL info for %s\n", reader->getPath());
+ //for(std::vector<HeaderRange>::iterator it=ranges.begin(); it != ranges.end(); ++it) {
+ // fprintf(stderr, "%08X %s\n", it->sum, it->begin->string);
+ //}
+
+ // see if any of these BINCL/EINCL ranges have already been seen and therefore can be replaced with EXCL
+ for(std::vector<HeaderRange>::iterator it=ranges.begin(); it != ranges.end(); ++it) {
+ if ( ! it->cannotEXCL ) {
+ const char* header = it->begin->string;
+ uint32_t sum = it->sum;
+ PathToSums::iterator pos = sKnownBINCLs.find(header);
+ if ( pos != sKnownBINCLs.end() ) {
+ std::vector<uint32_t>& sums = pos->second;
+ for(std::vector<uint32_t>::iterator sit=sums.begin(); sit != sums.end(); ++sit) {
+ if (*sit == sum) {
+ //fprintf(stderr, "use EXCL for %s in %s\n", header, reader->getPath());
+ it->useEXCL = true;
+ break;
+ }
+ }
+ if ( ! it->useEXCL ) {
+ // have seen this path, but not this checksum
+ //fprintf(stderr, "registering another checksum %08X for %s\n", sum, header);
+ sums.push_back(sum);
+ }
+ }
+ else {
+ // have not seen this path, so add to known BINCLs
+ std::vector<uint32_t> empty;
+ sKnownBINCLs[header] = empty;
+ sKnownBINCLs[header].push_back(sum);
+ //fprintf(stderr, "registering checksum %08X for %s\n", sum, header);
+ }
+ }
+ }
+
+ // add a new set of stabs with BINCL/EINCL runs that have been seen before, replaced with EXCLs
+ curRangeIndex = -1;
+ const int maxRangeIndex = ranges.size();
+ int soIndex = 0;
+ for(std::vector<ObjectFile::Reader::Stab>::iterator it=readerStabs->begin(); it != readerStabs->end(); ++it) {
+ switch ( it->type ) {
+ case N_BINCL:
+ for(int i=curRangeIndex+1; i < maxRangeIndex; ++i) {
+ if ( ranges[i].begin == it ) {
+ curRangeIndex = i;
+ HeaderRange& range = ranges[curRangeIndex];
+ ObjectFile::Reader::Stab stab = *it;
+ stab.value = range.sum; // BINCL and EXCL have n_value set to checksum
+ if ( range.useEXCL )
+ stab.type = N_EXCL; // transform BINCL into EXCL
+ if ( !minimal )
+ fStabs.push_back(stab);
+ break;
+ }
+ }
+ break;
+ case N_EINCL:
+ if ( curRangeIndex != -1 ) {
+ if ( !ranges[curRangeIndex].useEXCL && !minimal )
+ fStabs.push_back(*it);
+ curRangeIndex = ranges[curRangeIndex].parentRangeIndex;
+ }
+ break;
+ default:
+ if ( (curRangeIndex == -1) || !ranges[curRangeIndex].useEXCL ) {
+ ObjectFile::Reader::Stab stab = *it;
+ if ( !minimal || minimizeStab(stab) ) {
+ if ( stab.type == N_SO ) {
+ if ( (stab.string != NULL) && (strlen(stab.string) > 0) ) {
+ // starting SO is associated with first atom
+ stab.atom = soRanges[soIndex].first;
+ }
+ else {
+ // ending SO is associated with last atom
+ stab.atom = soRanges[soIndex].second;
+ ++soIndex;
+ }
+ }
+ fStabs.push_back(stab);
+ }
+ }
+ }
+ }
+
+}
+
+
+// used to prune out atoms that don't need debug notes generated
+class NoDebugNoteAtom
+{
+public:
+ NoDebugNoteAtom(const std::map<class ObjectFile::Reader*, uint32_t>& readersWithDwarfOrdinals)
+ : fReadersWithDwarfOrdinals(readersWithDwarfOrdinals) {}
+
+ bool operator()(const ObjectFile::Atom* atom) const {
+ if ( atom->getSymbolTableInclusion() == ObjectFile::Atom::kSymbolTableNotIn )
+ return true;
+ if ( atom->getName() == NULL )
+ return true;
+ if ( fReadersWithDwarfOrdinals.find(atom->getFile()) == fReadersWithDwarfOrdinals.end() )
+ return true;
+ return false;
+ }
+
+private:
+ const std::map<class ObjectFile::Reader*, uint32_t>& fReadersWithDwarfOrdinals;
+};
+
+// used to sort atoms with debug notes
+class ReadersWithDwarfSorter
+{
+public:
+ ReadersWithDwarfSorter(const std::map<class ObjectFile::Reader*, uint32_t>& readersWithDwarfOrdinals,
+ const std::map<const class ObjectFile::Atom*, uint32_t>& atomOrdinals)
+ : fReadersWithDwarfOrdinals(readersWithDwarfOrdinals), fAtomOrdinals(atomOrdinals) {}
+
+ bool operator()(const ObjectFile::Atom* left, const ObjectFile::Atom* right) const
+ {
+ // first sort by reader
+ unsigned int leftReaderIndex = fReadersWithDwarfOrdinals.find(left->getFile())->second;
+ unsigned int rightReaderIndex = fReadersWithDwarfOrdinals.find(right->getFile())->second;
+ if ( leftReaderIndex != rightReaderIndex )
+ return (leftReaderIndex < rightReaderIndex);
+
+ // then sort by atom ordinal
+ unsigned int leftAtomIndex = fAtomOrdinals.find(left)->second;
+ unsigned int rightAtomIndex = fAtomOrdinals.find(right)->second;
+ return leftAtomIndex < rightAtomIndex;
+ }
+
+private:
+ const std::map<class ObjectFile::Reader*, uint32_t>& fReadersWithDwarfOrdinals;
+ const std::map<const class ObjectFile::Atom*, uint32_t>& fAtomOrdinals;
+};
+
+
+
+
+
+void Linker::synthesizeDebugNotes(std::vector<class ObjectFile::Atom*>& allAtomsByReader)
+{
+ // synthesize "debug notes" and add them to master stabs vector
+ const char* dirPath = NULL;
+ const char* filename = NULL;
+ bool wroteStartSO = false;
+ bool useZeroOSOModTime = (getenv("RC_RELEASE") != NULL);
+ __gnu_cxx::hash_set<const char*, __gnu_cxx::hash<const char*>, CStringEquals> seenFiles;
+ for (std::vector<ObjectFile::Atom*>::iterator it=allAtomsByReader.begin(); it != allAtomsByReader.end(); it++) {
+ ObjectFile::Atom* atom = *it;
+ const char* newDirPath;
+ const char* newFilename;
+ //fprintf(stderr, "debug note for %s\n", atom->getDisplayName());
+ if ( atom->getTranslationUnitSource(&newDirPath, &newFilename) ) {
+ // need SO's whenever the translation unit source file changes
+ if ( newFilename != filename ) {
+ // gdb like directory SO's to end in '/', but dwarf DW_AT_comp_dir usually does not have trailing '/'
+ if ( (newDirPath != NULL) && (strlen(newDirPath) > 1 ) && (newDirPath[strlen(newDirPath)-1] != '/') )
+ asprintf((char**)&newDirPath, "%s/", newDirPath);
+ if ( filename != NULL ) {
+ // translation unit change, emit ending SO
+ ObjectFile::Reader::Stab endFileStab;
+ endFileStab.atom = NULL;
+ endFileStab.type = N_SO;
+ endFileStab.other = 1;
+ endFileStab.desc = 0;
+ endFileStab.value = 0;
+ endFileStab.string = "";
+ fStabs.push_back(endFileStab);
+ }
+ // new translation unit, emit start SO's
+ ObjectFile::Reader::Stab dirPathStab;
+ dirPathStab.atom = NULL;
+ dirPathStab.type = N_SO;
+ dirPathStab.other = 0;
+ dirPathStab.desc = 0;
+ dirPathStab.value = 0;
+ dirPathStab.string = newDirPath;
+ fStabs.push_back(dirPathStab);
+ ObjectFile::Reader::Stab fileStab;
+ fileStab.atom = NULL;
+ fileStab.type = N_SO;
+ fileStab.other = 0;
+ fileStab.desc = 0;
+ fileStab.value = 0;
+ fileStab.string = newFilename;
+ fStabs.push_back(fileStab);
+ // Synthesize OSO for start of file
+ ObjectFile::Reader::Stab objStab;
+ objStab.atom = NULL;
+ objStab.type = N_OSO;
+ // <rdar://problem/6337329> linker should put cpusubtype in n_sect field of nlist entry for N_OSO debug note entries
+ objStab.other = atom->getFile()->updateCpuConstraint(0);
+ objStab.desc = 1;
+ objStab.value = useZeroOSOModTime ? 0 : atom->getFile()->getModificationTime();
+ objStab.string = assureFullPath(atom->getFile()->getPath());
+ fStabs.push_back(objStab);
+ wroteStartSO = true;
+ // add the source file path to seenFiles so it does not show up in SOLs
+ seenFiles.insert(newFilename);
+ }
+ filename = newFilename;
+ dirPath = newDirPath;
+ if ( atom->getSegment().isContentExecutable() && (strncmp(atom->getSectionName(), "__text", 6) == 0) ) {
+ // Synthesize BNSYM and start FUN stabs
+ ObjectFile::Reader::Stab beginSym;
+ beginSym.atom = atom;
+ beginSym.type = N_BNSYM;
+ beginSym.other = 1;
+ beginSym.desc = 0;
+ beginSym.value = 0;
+ beginSym.string = "";
+ fStabs.push_back(beginSym);
+ ObjectFile::Reader::Stab startFun;
+ startFun.atom = atom;
+ startFun.type = N_FUN;
+ startFun.other = 1;
+ startFun.desc = 0;
+ startFun.value = 0;
+ startFun.string = atom->getName();
+ fStabs.push_back(startFun);
+ // Synthesize any SOL stabs needed
+ std::vector<ObjectFile::LineInfo>* lineInfo = atom->getLineInfo();
+ if ( lineInfo != NULL ) {
+ const char* curFile = NULL;
+ for (std::vector<ObjectFile::LineInfo>::iterator it = lineInfo->begin(); it != lineInfo->end(); ++it) {
+ if ( it->fileName != curFile ) {
+ if ( seenFiles.count(it->fileName) == 0 ) {
+ seenFiles.insert(it->fileName);
+ ObjectFile::Reader::Stab sol;
+ sol.atom = 0;
+ sol.type = N_SOL;
+ sol.other = 0;
+ sol.desc = 0;
+ sol.value = 0;
+ sol.string = it->fileName;
+ fStabs.push_back(sol);
+ }
+ curFile = it->fileName;
+ }
+ }
+ }
+ // Synthesize end FUN and ENSYM stabs
+ ObjectFile::Reader::Stab endFun;
+ endFun.atom = atom;
+ endFun.type = N_FUN;
+ endFun.other = 0;
+ endFun.desc = 0;
+ endFun.value = 0;
+ endFun.string = "";
+ fStabs.push_back(endFun);
+ ObjectFile::Reader::Stab endSym;
+ endSym.atom = atom;
+ endSym.type = N_ENSYM;
+ endSym.other = 1;
+ endSym.desc = 0;
+ endSym.value = 0;
+ endSym.string = "";
+ fStabs.push_back(endSym);
+ }
+ else if ( atom->getSymbolTableInclusion() == ObjectFile::Atom::kSymbolTableNotIn ) {
+ // no stabs for atoms that would not be in the symbol table
+ }
+ else if ( atom->getSymbolTableInclusion() == ObjectFile::Atom::kSymbolTableInAsAbsolute ) {
+ // no stabs for absolute symbols
+ }
+ else if ( (strcmp(atom->getSectionName(), "__eh_frame") == 0) ) {
+ // no stabs for .eh atoms
+ }
+ else if ( (strncmp(atom->getName(), "__dtrace_probe$", 15) == 0) ) {
+ // no stabs for old style dtrace probes
+ }
+ else {
+ ObjectFile::Reader::Stab globalsStab;
+ const char* name = atom->getName();
+ if ( atom->getScope() == ObjectFile::Atom::scopeTranslationUnit ) {
+ // Synthesize STSYM stab for statics
+ globalsStab.atom = atom;
+ globalsStab.type = N_STSYM;
+ globalsStab.other = 1;
+ globalsStab.desc = 0;
+ globalsStab.value = 0;
+ globalsStab.string = name;
+ fStabs.push_back(globalsStab);
+ }
+ else {
+ // Synthesize GSYM stab for other globals
+ globalsStab.atom = atom;
+ globalsStab.type = N_GSYM;
+ globalsStab.other = 1;
+ globalsStab.desc = 0;
+ globalsStab.value = 0;
+ globalsStab.string = name;
+ fStabs.push_back(globalsStab);
+ }
+ }
+ }
+ }
+
+ if ( wroteStartSO ) {
+ // emit ending SO
+ ObjectFile::Reader::Stab endFileStab;
+ endFileStab.atom = NULL;
+ endFileStab.type = N_SO;
+ endFileStab.other = 1;
+ endFileStab.desc = 0;
+ endFileStab.value = 0;
+ endFileStab.string = "";
+ fStabs.push_back(endFileStab);
+ }
+}
+
+
+
+
+void Linker::collectDebugInfo()
+{
+ std::map<const class ObjectFile::Atom*, uint32_t> atomOrdinals;
+ fStartDebugTime = mach_absolute_time();
+ if ( fOptions.readerOptions().fDebugInfoStripping != ObjectFile::ReaderOptions::kDebugInfoNone ) {
+
+ // determine mixture of stabs and dwarf
+ bool someStabs = false;
+ bool someDwarf = false;
+ for (std::vector<class ObjectFile::Reader*>::iterator it=fReadersThatHaveSuppliedAtoms.begin();
+ it != fReadersThatHaveSuppliedAtoms.end();
+ it++) {
+ ObjectFile::Reader* reader = *it;
+ if ( reader != NULL ) {
+ switch ( reader->getDebugInfoKind() ) {
+ case ObjectFile::Reader::kDebugInfoNone:
+ break;
+ case ObjectFile::Reader::kDebugInfoStabs:
+ someStabs = true;
+ break;
+ case ObjectFile::Reader::kDebugInfoDwarf:
+ someDwarf = true;
+ fCreateUUID = true;
+ break;
+ case ObjectFile::Reader::kDebugInfoStabsUUID:
+ someStabs = true;
+ fCreateUUID = true;
+ break;
+ default:
+ throw "Unhandled type of debug information";
+ }
+ }
+ }
+
+ if ( someDwarf || someStabs ) {
+ // try to minimize re-allocations
+ fStabs.reserve(1024);
+
+ // make mapping from atoms to ordinal
+ uint32_t ordinal = 1;
+ for (std::vector<ObjectFile::Atom*>::iterator it=fAllAtoms.begin(); it != fAllAtoms.end(); it++) {
+ atomOrdinals[*it] = ordinal++;
+ }
+ }
+
+ // process all dwarf .o files as a batch
+ if ( someDwarf ) {
+ // make mapping from readers with dwarf to ordinal
+ std::map<class ObjectFile::Reader*, uint32_t> readersWithDwarfOrdinals;
+ uint32_t readerOrdinal = 1;
+ for (std::vector<class ObjectFile::Reader*>::iterator it=fReadersThatHaveSuppliedAtoms.begin();
+ it != fReadersThatHaveSuppliedAtoms.end();
+ it++) {
+ ObjectFile::Reader* reader = *it;
+ if ( (reader != NULL) && (reader->getDebugInfoKind() == ObjectFile::Reader::kDebugInfoDwarf) ) {
+ readersWithDwarfOrdinals[reader] = readerOrdinal++;
+ }
+ }
+
+ // make a vector of atoms
+ std::vector<class ObjectFile::Atom*> allAtomsByReader(fAllAtoms.begin(), fAllAtoms.end());
+ // remove those not from a reader that has dwarf
+ allAtomsByReader.erase(std::remove_if(allAtomsByReader.begin(), allAtomsByReader.end(),
+ NoDebugNoteAtom(readersWithDwarfOrdinals)), allAtomsByReader.end());
+ // sort by reader then atom ordinal
+ std::sort(allAtomsByReader.begin(), allAtomsByReader.end(), ReadersWithDwarfSorter(readersWithDwarfOrdinals, atomOrdinals));
+ // add debug notes for each atom
+ this->synthesizeDebugNotes(allAtomsByReader);
+ }
+
+ // process all stabs .o files one by one
+ if ( someStabs ) {
+ // get stabs from each reader, in command line order
+ for (std::vector<class ObjectFile::Reader*>::iterator it=fReadersThatHaveSuppliedAtoms.begin();
+ it != fReadersThatHaveSuppliedAtoms.end();
+ it++) {
+ ObjectFile::Reader* reader = *it;
+ if ( reader != NULL ) {
+ switch ( reader->getDebugInfoKind() ) {
+ case ObjectFile::Reader::kDebugInfoDwarf:
+ case ObjectFile::Reader::kDebugInfoNone:
+ // do nothing
+ break;
+ case ObjectFile::Reader::kDebugInfoStabs:
+ case ObjectFile::Reader::kDebugInfoStabsUUID:
+ collectStabs(reader, atomOrdinals);
+ break;
+ default:
+ throw "Unhandled type of debug information";
+ }
+ }
+ }
+ // remove stabs associated with atoms that won't be in output
+ std::set<class ObjectFile::Atom*> allAtomsSet;
+ allAtomsSet.insert(fAllAtoms.begin(), fAllAtoms.end());
+ fStabs.erase(std::remove_if(fStabs.begin(), fStabs.end(), NotInSet(allAtomsSet)), fStabs.end());
+ }
+ }
+}
+
+void Linker::writeOutput()
+{
+ if ( fOptions.forceCpuSubtypeAll() )
+ fCurrentCpuConstraint = ObjectFile::Reader::kCpuAny;
+
+ fStartWriteTime = mach_absolute_time();
+ // tell writer about each segment's atoms
+ fOutputFileSize = fOutputFile->write(fAllAtoms, fStabs, this->entryPoint(true),
+ this->dyldClassicHelper(),this->dyldCompressedHelper(), this->dyldLazyLibraryHelper(),
+ fCreateUUID, fCanScatter,
+ fCurrentCpuConstraint, fBiggerThanTwoGigOutput,
+ fRegularDefAtomsThatOverrideADylibsWeakDef,
+ fGlobalSymbolTable.hasExternalWeakDefinitions());
+}
+
+ObjectFile::Reader* Linker::createReader(const Options::FileInfo& info)
+{
+ // map in whole file
+ uint64_t len = info.fileLen;
+ int fd = ::open(info.path, O_RDONLY, 0);
+ if ( fd == -1 )
+ throwf("can't open file, errno=%d", errno);
+ if ( info.fileLen < 20 )
+ throw "file too small";
+
+ uint8_t* p = (uint8_t*)::mmap(NULL, info.fileLen, PROT_READ, MAP_FILE | MAP_PRIVATE, fd, 0);
+ if ( p == (uint8_t*)(-1) )
+ throwf("can't map file, errno=%d", errno);
+
+ // if fat file, skip to architecture we want
+ // Note: fat header is always big-endian
+ const fat_header* fh = (fat_header*)p;
+ if ( fh->magic == OSSwapBigToHostInt32(FAT_MAGIC) ) {
+ const struct fat_arch* archs = (struct fat_arch*)(p + sizeof(struct fat_header));
+ uint32_t sliceToUse;
+ bool sliceFound = false;
+ if ( fOptions.preferSubArchitecture() ) {
+ // first try to find a slice that match cpu-type and cpu-sub-type
+ for (uint32_t i=0; i < OSSwapBigToHostInt32(fh->nfat_arch); ++i) {
+ if ( (OSSwapBigToHostInt32(archs[i].cputype) == (uint32_t)fArchitecture)
+ && (OSSwapBigToHostInt32(archs[i].cpusubtype) == (uint32_t)fOptions.subArchitecture()) ) {
+ sliceToUse = i;
+ sliceFound = true;
+ break;
+ }
+ }
+ }
+ if ( !sliceFound ) {
+ // look for any slice that matches just cpu-type
+ for (uint32_t i=0; i < OSSwapBigToHostInt32(fh->nfat_arch); ++i) {
+ if ( OSSwapBigToHostInt32(archs[i].cputype) == (uint32_t)fArchitecture ) {
+ sliceToUse = i;
+ sliceFound = true;
+ break;
+ }
+ }
+ }
+ if ( sliceFound ) {
+ uint32_t fileOffset = OSSwapBigToHostInt32(archs[sliceToUse].offset);
+ len = OSSwapBigToHostInt32(archs[sliceToUse].size);
+ // if requested architecture is page aligned within fat file, then remap just that portion of file
+ if ( (fileOffset & 0x00000FFF) == 0 ) {
+ // unmap whole file
+ munmap((caddr_t)p, info.fileLen);
+ // re-map just part we need
+ p = (uint8_t*)::mmap(NULL, len, PROT_READ, MAP_FILE | MAP_PRIVATE, fd, fileOffset);
+ if ( p == (uint8_t*)(-1) )
+ throwf("can't re-map file, errno=%d", errno);
+ }
+ else {
+ p = &p[fileOffset];
+ }
+ }
+ }
+ ::close(fd);
+
+ bool objSubtypeMustMatch = (fOptions.preferSubArchitecture() && !fOptions.allowSubArchitectureMismatches());
+ switch (fArchitecture) {
+ case CPU_TYPE_POWERPC:
+ if ( mach_o::relocatable::Reader<ppc>::validFile(p) )
+ return this->addObject(new mach_o::relocatable::Reader<ppc>::Reader(p, info.path, info.modTime, fOptions.readerOptions(), fNextInputOrdinal), info, len);
+ else if ( mach_o::dylib::Reader<ppc>::validFile(p, info.options.fBundleLoader) )
+ return this->addDylib(new mach_o::dylib::Reader<ppc>::Reader(p, len, info.path, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
+ else if ( archive::Reader<ppc>::validFile(p, len) )
+ return this->addArchive(new archive::Reader<ppc>::Reader(p, len, info.path, info.modTime, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
+ break;
+ case CPU_TYPE_POWERPC64:
+ if ( mach_o::relocatable::Reader<ppc64>::validFile(p) )
+ return this->addObject(new mach_o::relocatable::Reader<ppc64>::Reader(p, info.path, info.modTime, fOptions.readerOptions(), fNextInputOrdinal), info, len);
+ else if ( mach_o::dylib::Reader<ppc64>::validFile(p, info.options.fBundleLoader) )
+ return this->addDylib(new mach_o::dylib::Reader<ppc64>::Reader(p, len, info.path, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
+ else if ( archive::Reader<ppc64>::validFile(p, len) )
+ return this->addArchive(new archive::Reader<ppc64>::Reader(p, len, info.path, info.modTime, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
+ break;
+ case CPU_TYPE_I386:
+ if ( mach_o::relocatable::Reader<x86>::validFile(p) )
+ return this->addObject(new mach_o::relocatable::Reader<x86>::Reader(p, info.path, info.modTime, fOptions.readerOptions(), fNextInputOrdinal), info, len);
+ else if ( mach_o::dylib::Reader<x86>::validFile(p, info.options.fBundleLoader) )
+ return this->addDylib(new mach_o::dylib::Reader<x86>::Reader(p, len, info.path, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
+ else if ( archive::Reader<x86>::validFile(p, len) )
+ return this->addArchive(new archive::Reader<x86>::Reader(p, len, info.path, info.modTime, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
+ break;
+ case CPU_TYPE_X86_64:
+ if ( mach_o::relocatable::Reader<x86_64>::validFile(p) )
+ return this->addObject(new mach_o::relocatable::Reader<x86_64>::Reader(p, info.path, info.modTime, fOptions.readerOptions(), fNextInputOrdinal), info, len);
+ else if ( mach_o::dylib::Reader<x86_64>::validFile(p, info.options.fBundleLoader) )
+ return this->addDylib(new mach_o::dylib::Reader<x86_64>::Reader(p, len, info.path, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
+ else if ( archive::Reader<x86_64>::validFile(p, len) )
+ return this->addArchive(new archive::Reader<x86_64>::Reader(p, len, info.path, info.modTime, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
+ case CPU_TYPE_ARM:
+ if ( mach_o::relocatable::Reader<arm>::validFile(p, objSubtypeMustMatch, fOptions.subArchitecture()) )
+ return this->addObject(new mach_o::relocatable::Reader<arm>::Reader(p, info.path, info.modTime, fOptions.readerOptions(), fNextInputOrdinal), info, len);
+ else if ( mach_o::dylib::Reader<arm>::validFile(p, info.options.fBundleLoader) )
+ return this->addDylib(new mach_o::dylib::Reader<arm>::Reader(p, len, info.path, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
+ else if ( archive::Reader<arm>::validFile(p, len) )
+ return this->addArchive(new archive::Reader<arm>::Reader(p, len, info.path, info.modTime, info.options, fOptions.readerOptions(), fNextInputOrdinal), info, len);
+ break;
+ }
+
+#if LTO_SUPPORT
+ if ( lto::Reader::validFile(p, len, fArchitecture) ) {
+ return this->addObject(new lto::Reader(p, len, info.path, info.modTime, fOptions.readerOptions(), fArchitecture), info, len);
+ }
+ else if ( !lto::Reader::loaded() && (p[0] == 'B') && (p[1] == 'C') ) {
+ throw "could not process object file. Looks like an llvm bitcode object file, but libLTO.dylib could not be loaded";
+ }
+#endif
+ // error handling
+ if ( ((fat_header*)p)->magic == OSSwapBigToHostInt32(FAT_MAGIC) ) {
+ throwf("missing required architecture %s in file", fArchitectureName);
+ }
+ else {
+ throw "file is not of required architecture";
+ }
+}
+
+void Linker::logDylib(ObjectFile::Reader* reader, bool indirect)
+{
+ if ( fOptions.readerOptions().fTraceDylibs ) {
+ const char* fullPath = reader->getPath();
+ char realName[MAXPATHLEN];
+ if ( realpath(fullPath, realName) != NULL )
+ fullPath = realName;
+ if ( indirect )
+ logTraceInfo("[Logging for XBS] Used indirect dynamic library: %s\n", fullPath);
+ else
+ logTraceInfo("[Logging for XBS] Used dynamic library: %s\n", fullPath);
+ }
+}
+
+
+
+ObjectFile::Reader* Linker::findDylib(const char* installPath, const char* fromPath)
+{
+ //fprintf(stderr, "findDylib(%s, %s)\n", installPath, fromPath);
+ InstallNameToReader::iterator pos = fDylibMap.find(installPath);
+ if ( pos != fDylibMap.end() ) {
+ return pos->second;
+ }
+ else {
+ // allow -dylib_path option to override indirect library to use
+ for (std::vector<Options::DylibOverride>::iterator dit = fOptions.dylibOverrides().begin(); dit != fOptions.dylibOverrides().end(); ++dit) {
+ if ( strcmp(dit->installName,installPath) == 0 ) {\
+ try {
+ Options::FileInfo info = fOptions.findFile(dit->useInstead);
+ ObjectFile::Reader* reader = this->createReader(info);
+ fDylibMap[strdup(installPath)] = reader;
+ this->logDylib(reader, true);
+ return reader;
+ }
+ catch (const char* msg) {
+ warning("ignoring -dylib_file option, %s", msg);
+ }
+ }
+ }
+ char newPath[MAXPATHLEN];
+ // handle @loader_path
+ if ( strncmp(installPath, "@loader_path/", 13) == 0 ) {
+ strcpy(newPath, fromPath);
+ char* addPoint = strrchr(newPath,'/');
+ if ( addPoint != NULL )
+ strcpy(&addPoint[1], &installPath[13]);
+ else
+ strcpy(newPath, &installPath[13]);
+ installPath = newPath;
+ }
+ // note: @executable_path case is handled inside findFileUsingPaths()
+ // search for dylib using -F and -L paths
+ Options::FileInfo info = fOptions.findFileUsingPaths(installPath);
+ try {
+ ObjectFile::Reader* reader = this->createReader(info);
+ fDylibMap[strdup(installPath)] = reader;
+ this->logDylib(reader, true);
+ return reader;
+ }
+ catch (const char* msg) {
+ throwf("in %s, %s", info.path, msg);
+ }
+ }
+}
+
+
+void Linker::processDylibs()
+{
+ fAllDirectDylibsLoaded = true;
+
+ // mark all dylibs initially specified as required and check if they can be used
+ for (InstallNameToReader::iterator it=fDylibMap.begin(); it != fDylibMap.end(); it++) {
+ it->second->setExplicitlyLinked();
+ this->checkDylibClientRestrictions(it->second);
+ }
+
+ // keep processing dylibs until no more dylibs are added
+ unsigned long lastMapSize = 0;
+ while ( lastMapSize != fDylibMap.size() ) {
+ lastMapSize = fDylibMap.size();
+ // can't iterator fDylibMap while modifying it, so use temp buffer
+ std::vector<ObjectFile::Reader*> currentUnprocessedReaders;
+ for (InstallNameToReader::iterator it=fDylibMap.begin(); it != fDylibMap.end(); it++) {
+ if ( fDylibsProcessed.count(it->second) == 0 )
+ currentUnprocessedReaders.push_back(it->second);
+ }
+ for (std::vector<ObjectFile::Reader*>::iterator it=currentUnprocessedReaders.begin(); it != currentUnprocessedReaders.end(); it++) {
+ fDylibsProcessed.insert(*it);
+ (*it)->processIndirectLibraries(this);
+ }
+ }
+
+ // go back over original dylibs and mark sub frameworks as re-exported
+ if ( fOptions.outputKind() == Options::kDynamicLibrary ) {
+ const char* myLeaf = strrchr(fOptions.installPath(), '/');
+ if ( myLeaf != NULL ) {
+ for (std::vector<class ObjectFile::Reader*>::iterator it=fInputFiles.begin(); it != fInputFiles.end(); it++) {
+ ObjectFile::Reader* reader = *it;
+ const char* childParent = reader->parentUmbrella();
+ if ( childParent != NULL ) {
+ if ( strcmp(childParent, &myLeaf[1]) == 0 ) {
+ // set re-export bit of info
+ std::map<ObjectFile::Reader*,LibraryOptions>::iterator pos = fDylibOptionsMap.find(reader);
+ if ( pos != fDylibOptionsMap.end() ) {
+ pos->second.fReExport = true;
+ }
+ }
+ }
+ }
+ }
+ }
+
+}
+
+
+
+void Linker::createReaders()
+{
+ fStartCreateReadersTime = mach_absolute_time();
+ std::vector<Options::FileInfo>& files = fOptions.getInputFiles();
+ const int count = files.size();
+ if ( count == 0 )
+ throw "no object files specified";
+ // add all direct object, archives, and dylibs
+ for (int i=0; i < count; ++i) {
+ Options::FileInfo& entry = files[i];
+ // ignore /usr/lib/dyld on command line in crt.o build
+ if ( strcmp(entry.path, "/usr/lib/dyld") != 0 ) {
+ try {
+ this->addInputFile(this->createReader(entry), entry);
+ }
+ catch (const char* msg) {
+ if ( (strstr(msg, "architecture") != NULL) && !fOptions.errorOnOtherArchFiles() ) {
+ if ( fOptions.ignoreOtherArchInputFiles() ) {
+ // ignore, because this is about an architecture not in use
+ }
+ else {
+ warning("in %s, %s", entry.path, msg);
+ }
+ }
+ else {
+ throwf("in %s, %s", entry.path, msg);
+ }
+ }
+ }
+ }
+
+ this->processDylibs();
+}
+
+
+
+ObjectFile::Reader* Linker::addArchive(ObjectFile::Reader* reader, const Options::FileInfo& info, uint64_t mappedLen)
+{
+ fNextInputOrdinal += mappedLen;
+ // remember which readers are archives because they are logged differently
+ fArchiveReaders.insert(reader);
+
+ // update stats
+ fTotalArchiveSize += mappedLen;
+ ++fTotalArchivesLoaded;
+ return reader;
+}
+
+ObjectFile::Reader* Linker::addObject(ObjectFile::Reader* reader, const Options::FileInfo& info, uint64_t mappedLen)
+{
+ fNextInputOrdinal += mappedLen;
+ // any .o files that don't have MH_SUBSECTIONS_VIA_SYMBOLS, that means a generated .o file can't
+ if ( (fOptions.outputKind() == Options::kObjectFile) && !reader->canScatterAtoms() )
+ fCanScatter = false;
+
+ // update stats
+ fTotalObjectSize += mappedLen;
+ ++fTotalObjectLoaded;
+ return reader;
+}
+
+
+void Linker::checkDylibClientRestrictions(ObjectFile::Reader* reader)
+{
+ // Check for any restrictions on who can link with this dylib
+ const char* readerParentName = reader->parentUmbrella() ;
+ std::vector<const char*>* clients = reader->getAllowableClients();
+ if ( (readerParentName != NULL) || (clients != NULL) ) {
+ // only dylibs that are in an umbrella or have a client list need verification
+ const char* installName = fOptions.installPath();
+ const char* installNameLastSlash = strrchr(installName, '/');
+ bool isParent = false;
+ bool isSibling = false;
+ bool isAllowableClient = false;
+ // There are three cases:
+ if ( (readerParentName != NULL) && (installNameLastSlash != NULL) ) {
+ // case 1) The dylib has a parent umbrella, and we are creating the parent umbrella
+ isParent = ( strcmp(&installNameLastSlash[1], readerParentName) == 0 );
+
+ // hack to support umbrella variants that encode the variant name in the install name
+ // e.g. CoreServices_profile
+ if ( !isParent ) {
+ const char* underscore = strchr(&installNameLastSlash[1], '_');
+ if ( underscore != NULL ) {
+ isParent = ( strncmp(&installNameLastSlash[1], readerParentName, underscore-installNameLastSlash-1) == 0 );
+ }
+ }
+
+ // case 2) The dylib has a parent umbrella, and we are creating a sibling with the same parent
+ isSibling = ( (fOptions.umbrellaName() != NULL) && (strcmp(fOptions.umbrellaName(), readerParentName) == 0) );
+ }
+
+ if ( !isParent && !isSibling && (clients != NULL) ) {
+ // case 3) the dylib has a list of allowable clients, and we are creating one of them
+ const char* clientName = fOptions.clientName();
+ int clientNameLen = 0;
+ if ( clientName != NULL ) {
+ // use client name as specified on command line
+ clientNameLen = strlen(clientName);
+ }
+ else {
+ // infer client name from output path (e.g. xxx/libfoo_variant.A.dylib --> foo, Bar.framework/Bar_variant --> Bar)
+ clientName = installName;
+ clientNameLen = strlen(clientName);
+ // starts after last slash
+ if ( installNameLastSlash != NULL )
+ clientName = &installNameLastSlash[1];
+ if ( strncmp(clientName, "lib", 3) == 0 )
+ clientName = &clientName[3];
+ // up to first dot
+ const char* firstDot = strchr(clientName, '.');
+ if ( firstDot != NULL )
+ clientNameLen = firstDot - clientName;
+ // up to first underscore
+ const char* firstUnderscore = strchr(clientName, '_');
+ if ( (firstUnderscore != NULL) && ((firstUnderscore - clientName) < clientNameLen) )
+ clientNameLen = firstUnderscore - clientName;
+ }
+
+ // Use clientName to check if this dylib is able to link against the allowable clients.
+ for (std::vector<const char*>::iterator it = clients->begin(); it != clients->end(); it++) {
+ if ( strncmp(*it, clientName, clientNameLen) == 0 )
+ isAllowableClient = true;
+ }
+ }
+
+ if ( !isParent && !isSibling && !isAllowableClient ) {
+ if ( readerParentName != NULL ) {
+ throwf("cannot link directly with %s. Link against the umbrella framework '%s.framework' instead.",
+ reader->getPath(), readerParentName);
+ }
+ else {
+ throwf("cannot link directly with %s", reader->getPath());
+ }
+ }
+ }
+}
+
+
+ObjectFile::Reader* Linker::addDylib(ObjectFile::Reader* reader, const Options::FileInfo& info, uint64_t mappedLen)
+{
+ switch ( fOptions.outputKind() ) {
+ case Options::kDynamicExecutable:
+ case Options::kDynamicLibrary:
+ case Options::kDynamicBundle:
+ break;
+ case Options::kStaticExecutable:
+ case Options::kDyld:
+ case Options::kPreload:
+ case Options::kObjectFile:
+ case Options::kKextBundle:
+ warning("unexpected dylib (%s) on link line", reader->getPath());
+ break;
+ }
+
+ fNextInputOrdinal += mappedLen;
+ if ( (reader->getInstallPath() == NULL) && !info.options.fBundleLoader ) {
+ // this is a "blank" stub
+ // silently ignore it
+ return reader;
+ }
+ // add to map of loaded dylibs
+ const char* installPath = reader->getInstallPath();
+ if ( installPath != NULL ) {
+ InstallNameToReader::iterator pos = fDylibMap.find(installPath);
+ if ( pos == fDylibMap.end() ) {
+ fDylibMap[strdup(installPath)] = reader;
+ }
+ else {
+ InstallNameToReader::iterator pos2 = fDylibMap.find(reader->getPath());
+ if ( pos2 == fDylibMap.end() )
+ fDylibMap[strdup(reader->getPath())] = reader;
+ else
+ warning("duplicate dylib %s", reader->getPath());
+ }
+ }
+ else if ( info.options.fBundleLoader )
+ fBundleLoaderReader = reader;
+
+ // log direct readers
+ if ( !fAllDirectDylibsLoaded )
+ this->logDylib(reader, false);
+
+ // update stats
+ ++fTotalDylibsLoaded;
+
+ return reader;
+}
+
+
+void Linker::logTraceInfo (const char* format, ...)
+{
+ static int trace_file = -1;
+ char trace_buffer[MAXPATHLEN * 2];
+ char *buffer_ptr;
+ int length;
+ ssize_t amount_written;
+ const char *trace_file_path = fOptions.readerOptions().fTraceOutputFile;
+
+ if(trace_file == -1) {
+ if(trace_file_path != NULL) {
+ trace_file = open(trace_file_path, O_WRONLY | O_APPEND | O_CREAT, 0666);
+ if(trace_file == -1)
+ throwf("Could not open or create trace file: %s", trace_file_path);
+ }
+ else {
+ trace_file = fileno(stderr);
+ }
+ }
+
+ va_list ap;
+ va_start(ap, format);
+ length = vsnprintf(trace_buffer, sizeof(trace_buffer), format, ap);
+ va_end(ap);
+ buffer_ptr = trace_buffer;
+
+ while(length > 0) {
+ amount_written = write(trace_file, buffer_ptr, length);
+ if(amount_written == -1)
+ /* Failure to write shouldn't fail the build. */
+ return;
+ buffer_ptr += amount_written;
+ length -= amount_written;
+ }
+}
+
+
+
+void Linker::createWriter()
+{
+ fStartCreateWriterTime = mach_absolute_time();
+
+ // make a vector out of all required dylibs in fDylibMap
+ std::vector<ExecutableFile::DyLibUsed> dynamicLibraries;
+ // need to preserve command line order
+ for (std::vector<class ObjectFile::Reader*>::iterator it=fInputFiles.begin(); it != fInputFiles.end(); it++) {
+ ObjectFile::Reader* reader = *it;
+ for (InstallNameToReader::iterator mit=fDylibMap.begin(); mit != fDylibMap.end(); mit++) {
+ if ( reader == mit->second ) {
+ ExecutableFile::DyLibUsed dylibInfo;
+ dylibInfo.reader = reader;
+ dylibInfo.options = fDylibOptionsMap[reader];
+ dynamicLibraries.push_back(dylibInfo);
+ break;
+ }
+ }
+ }
+ // then add any other dylibs
+ for (InstallNameToReader::iterator it=fDylibMap.begin(); it != fDylibMap.end(); it++) {
+ if ( it->second->implicitlyLinked() ) {
+ // if not already in dynamicLibraries
+ bool alreadyInDynamicLibraries = false;
+ for (std::vector<ExecutableFile::DyLibUsed>::iterator dit=dynamicLibraries.begin(); dit != dynamicLibraries.end(); dit++) {
+ if ( dit->reader == it->second ) {
+ alreadyInDynamicLibraries = true;
+ break;
+ }
+ }
+ if ( ! alreadyInDynamicLibraries ) {
+ ExecutableFile::DyLibUsed dylibInfo;
+ dylibInfo.reader = it->second;
+ std::map<ObjectFile::Reader*,LibraryOptions>::iterator pos = fDylibOptionsMap.find(it->second);
+ if ( pos != fDylibOptionsMap.end() ) {
+ dylibInfo.options = pos->second;
+ }
+ else {
+ dylibInfo.options.fWeakImport = false; // FIX ME
+ dylibInfo.options.fReExport = false;
+ dylibInfo.options.fBundleLoader = false;
+ }
+ dynamicLibraries.push_back(dylibInfo);
+ }
+ }
+ }
+ if ( fBundleLoaderReader != NULL ) {
+ ExecutableFile::DyLibUsed dylibInfo;
+ dylibInfo.reader = fBundleLoaderReader;
+ dylibInfo.options.fWeakImport = false;
+ dylibInfo.options.fReExport = false;
+ dylibInfo.options.fBundleLoader = true;
+ dynamicLibraries.push_back(dylibInfo);
+ }
+
+ const char* path = fOptions.getOutputFilePath();
+ switch ( fArchitecture ) {
+ case CPU_TYPE_POWERPC:
+ this->setOutputFile(new mach_o::executable::Writer<ppc>(path, fOptions, dynamicLibraries));
+ break;
+ case CPU_TYPE_POWERPC64:
+ this->setOutputFile(new mach_o::executable::Writer<ppc64>(path, fOptions, dynamicLibraries));
+ break;
+ case CPU_TYPE_I386:
+ this->setOutputFile(new mach_o::executable::Writer<x86>(path, fOptions, dynamicLibraries));
+ break;
+ case CPU_TYPE_X86_64:
+ this->setOutputFile(new mach_o::executable::Writer<x86_64>(path, fOptions, dynamicLibraries));
+ break;
+ case CPU_TYPE_ARM:
+ this->setOutputFile(new mach_o::executable::Writer<arm>(path, fOptions, dynamicLibraries));
+ break;
+ default:
+ throw "unknown architecture";
+ }
+}
+
+
+Linker::SymbolTable::SymbolTable(Linker& owner)
+ : fOwner(owner), fRequireCount(0), fHasExternalTentativeDefinitions(false), fHasExternalWeakDefinitions(false)
+{
+}
+
+void Linker::SymbolTable::require(const char* name)
+{
+ //fprintf(stderr, "require(%s)\n", name);
+ Mapper::iterator pos = fTable.find(name);
+ if ( pos == fTable.end() ) {
+ fTable[name] = NULL;
+ ++fRequireCount;
+ }
+}
+
+// convenience labels for 2-dimensional switch statement
+enum AllDefinitionCombinations {
+ kRegAndReg = (ObjectFile::Atom::kRegularDefinition << 3) | ObjectFile::Atom::kRegularDefinition,
+ kRegAndWeak = (ObjectFile::Atom::kRegularDefinition << 3) | ObjectFile::Atom::kWeakDefinition,
+ kRegAndTent = (ObjectFile::Atom::kRegularDefinition << 3) | ObjectFile::Atom::kTentativeDefinition,
+ kRegAndExtern = (ObjectFile::Atom::kRegularDefinition << 3) | ObjectFile::Atom::kExternalDefinition,
+ kRegAndExternWeak = (ObjectFile::Atom::kRegularDefinition << 3) | ObjectFile::Atom::kExternalWeakDefinition,
+ kRegAndAbsolute = (ObjectFile::Atom::kRegularDefinition << 3) | ObjectFile::Atom::kAbsoluteSymbol,
+ kWeakAndReg = (ObjectFile::Atom::kWeakDefinition << 3) | ObjectFile::Atom::kRegularDefinition,
+ kWeakAndWeak = (ObjectFile::Atom::kWeakDefinition << 3) | ObjectFile::Atom::kWeakDefinition,
+ kWeakAndTent = (ObjectFile::Atom::kWeakDefinition << 3) | ObjectFile::Atom::kTentativeDefinition,
+ kWeakAndExtern = (ObjectFile::Atom::kWeakDefinition << 3) | ObjectFile::Atom::kExternalDefinition,
+ kWeakAndExternWeak = (ObjectFile::Atom::kWeakDefinition << 3) | ObjectFile::Atom::kExternalWeakDefinition,
+ kWeakAndAbsolute = (ObjectFile::Atom::kWeakDefinition << 3) | ObjectFile::Atom::kAbsoluteSymbol,
+ kTentAndReg = (ObjectFile::Atom::kTentativeDefinition << 3) | ObjectFile::Atom::kRegularDefinition,
+ kTentAndWeak = (ObjectFile::Atom::kTentativeDefinition << 3) | ObjectFile::Atom::kWeakDefinition,
+ kTentAndTent = (ObjectFile::Atom::kTentativeDefinition << 3) | ObjectFile::Atom::kTentativeDefinition,
+ kTentAndExtern = (ObjectFile::Atom::kTentativeDefinition << 3) | ObjectFile::Atom::kExternalDefinition,
+ kTentAndExternWeak = (ObjectFile::Atom::kTentativeDefinition << 3) | ObjectFile::Atom::kExternalWeakDefinition,
+ kTentAndAbsolute = (ObjectFile::Atom::kTentativeDefinition << 3) | ObjectFile::Atom::kAbsoluteSymbol,
+ kExternAndReg = (ObjectFile::Atom::kExternalDefinition << 3) | ObjectFile::Atom::kRegularDefinition,
+ kExternAndWeak = (ObjectFile::Atom::kExternalDefinition << 3) | ObjectFile::Atom::kWeakDefinition,
+ kExternAndTent = (ObjectFile::Atom::kExternalDefinition << 3) | ObjectFile::Atom::kTentativeDefinition,
+ kExternAndExtern = (ObjectFile::Atom::kExternalDefinition << 3) | ObjectFile::Atom::kExternalDefinition,
+ kExternAndExternWeak = (ObjectFile::Atom::kExternalDefinition << 3) | ObjectFile::Atom::kExternalWeakDefinition,
+ kExternAndAbsolute = (ObjectFile::Atom::kExternalDefinition << 3) | ObjectFile::Atom::kAbsoluteSymbol,
+ kExternWeakAndReg = (ObjectFile::Atom::kExternalWeakDefinition << 3) | ObjectFile::Atom::kRegularDefinition,
+ kExternWeakAndWeak = (ObjectFile::Atom::kExternalWeakDefinition << 3) | ObjectFile::Atom::kWeakDefinition,
+ kExternWeakAndTent = (ObjectFile::Atom::kExternalWeakDefinition << 3) | ObjectFile::Atom::kTentativeDefinition,
+ kExternWeakAndExtern = (ObjectFile::Atom::kExternalWeakDefinition << 3) | ObjectFile::Atom::kExternalDefinition,
+ kExternWeakAndExternWeak= (ObjectFile::Atom::kExternalWeakDefinition << 3) | ObjectFile::Atom::kExternalWeakDefinition,
+ kExternWeakAndAbsolute = (ObjectFile::Atom::kExternalWeakDefinition << 3) | ObjectFile::Atom::kAbsoluteSymbol,
+ kAbsoluteAndReg = (ObjectFile::Atom::kAbsoluteSymbol << 3) | ObjectFile::Atom::kRegularDefinition,
+ kAbsoluteAndWeak = (ObjectFile::Atom::kAbsoluteSymbol << 3) | ObjectFile::Atom::kWeakDefinition,
+ kAbsoluteAndTent = (ObjectFile::Atom::kAbsoluteSymbol << 3) | ObjectFile::Atom::kTentativeDefinition,
+ kAbsoluteAndExtern = (ObjectFile::Atom::kAbsoluteSymbol << 3) | ObjectFile::Atom::kExternalDefinition,
+ kAbsoluteAndExternWeak = (ObjectFile::Atom::kAbsoluteSymbol << 3) | ObjectFile::Atom::kExternalWeakDefinition,
+ kAbsoluteAndAbsolute = (ObjectFile::Atom::kAbsoluteSymbol << 3) | ObjectFile::Atom::kAbsoluteSymbol
+};
+
+bool Linker::SymbolTable::add(ObjectFile::Atom& newAtom)
+{
+ bool useNew = true;
+ bool checkVisibilityMismatch = false;
+ const char* name = newAtom.getName();
+ //fprintf(stderr, "map.add(%s => %p from %s)\n", name, &newAtom, newAtom.getFile()->getPath());
+ Mapper::iterator pos = fTable.find(name);
+ ObjectFile::Atom* existingAtom = NULL;
+ if ( pos != fTable.end() )
+ existingAtom = pos->second;
+ if ( existingAtom != NULL ) {
+ // already have atom with same name in symbol table
+ switch ( (AllDefinitionCombinations)((existingAtom->getDefinitionKind() << 3) | newAtom.getDefinitionKind()) ) {
+ case kRegAndReg:
+ throwf("duplicate symbol %s in %s and %s", name, newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
+ case kRegAndWeak:
+ // ignore new weak atom, because we already have a non-weak one
+ useNew = false;
+ break;
+ case kRegAndTent:
+ // ignore new tentative atom, because we already have a regular one
+ useNew = false;
+ checkVisibilityMismatch = true;
+ if ( newAtom.getSize() > existingAtom->getSize() ) {
+ warning("for symbol %s tentative definition of size %llu from %s is "
+ "is smaller than the real definition of size %llu from %s",
+ newAtom.getDisplayName(), newAtom.getSize(), newAtom.getFile()->getPath(),
+ existingAtom->getSize(), existingAtom->getFile()->getPath());
+ }
+ break;
+ case kRegAndExtern:
+ // ignore external atom, because we already have a one
+ useNew = false;
+ break;
+ case kRegAndExternWeak:
+ // ignore external atom, because we already have a one
+ useNew = false;
+ break;
+ case kRegAndAbsolute:
+ throwf("duplicate symbol %s in %s and %s", name, newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
+ break;
+ case kWeakAndReg:
+ // replace existing weak atom with regular one
+ break;
+ case kWeakAndWeak:
+ // have another weak atom, use whichever has largest alignment requirement
+ // because codegen of some client may require alignment
+ useNew = ( newAtom.getAlignment().trailingZeros() > existingAtom->getAlignment().trailingZeros() );
+ checkVisibilityMismatch = true;
+ break;
+ case kWeakAndTent:
+ // replace existing weak atom with tentative one ???
+ break;
+ case kWeakAndExtern:
+ // keep weak atom, at runtime external one may override
+ useNew = false;
+ break;
+ case kWeakAndExternWeak:
+ // keep weak atom, at runtime external one may override
+ useNew = false;
+ break;
+ case kWeakAndAbsolute:
+ // replace existing weak atom with absolute one
+ break;
+ case kTentAndReg:
+ // replace existing tentative atom with regular one
+ checkVisibilityMismatch = true;
+ if ( newAtom.getSize() < existingAtom->getSize() ) {
+ warning("for symbol %s tentative definition of size %llu from %s is "
+ "being replaced by a real definition of size %llu from %s",
+ newAtom.getDisplayName(), existingAtom->getSize(), existingAtom->getFile()->getPath(),
+ newAtom.getSize(), newAtom.getFile()->getPath());
+ }
+ break;
+ case kTentAndWeak:
+ // replace existing tentative atom with weak one ???
+ break;
+ case kTentAndTent:
+ // use largest
+ checkVisibilityMismatch = true;
+ if ( newAtom.getSize() < existingAtom->getSize() ) {
+ useNew = false;
+ }
+ else {
+ if ( newAtom.getAlignment().trailingZeros() < existingAtom->getAlignment().trailingZeros() )
+ warning("alignment lost in merging tentative definition %s", newAtom.getDisplayName());
+ }
+ break;
+ case kTentAndExtern:
+ case kTentAndExternWeak:
+ // a tentative definition and a dylib definition, so commons-mode decides how to handle
+ switch ( fOwner.fOptions.commonsMode() ) {
+ case Options::kCommonsIgnoreDylibs:
+ if ( fOwner.fOptions.warnCommons() )
+ warning("using common symbol %s from %s and ignoring defintion from dylib %s",
+ existingAtom->getName(), existingAtom->getFile()->getPath(), newAtom.getFile()->getPath());
+ useNew = false;
+ break;
+ case Options::kCommonsOverriddenByDylibs:
+ if ( fOwner.fOptions.warnCommons() )
+ warning("replacing common symbol %s from %s with true definition from dylib %s",
+ existingAtom->getName(), existingAtom->getFile()->getPath(), newAtom.getFile()->getPath());
+ break;
+ case Options::kCommonsConflictsDylibsError:
+ throwf("common symbol %s from %s conflicts with defintion from dylib %s",
+ existingAtom->getName(), existingAtom->getFile()->getPath(), newAtom.getFile()->getPath());
+ }
+ break;
+ case kTentAndAbsolute:
+ // replace tentative with absolute (can't size check because absolutes have no size)
+ break;
+ case kExternAndReg:
+ // replace external atom with regular one
+ break;
+ case kExternAndWeak:
+ // replace external atom with weak one
+ break;
+ case kExternAndTent:
+ // a tentative definition and a dylib definition, so commons-mode decides how to handle
+ switch ( fOwner.fOptions.commonsMode() ) {
+ case Options::kCommonsIgnoreDylibs:
+ if ( fOwner.fOptions.warnCommons() )
+ warning("using common symbol %s from %s and ignoring defintion from dylib %s",
+ newAtom.getName(), newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
+ break;
+ case Options::kCommonsOverriddenByDylibs:
+ if ( fOwner.fOptions.warnCommons() )
+ warning("replacing defintion of %s from dylib %s with common symbol from %s",
+ newAtom.getName(), existingAtom->getFile()->getPath(), newAtom.getFile()->getPath());
+ useNew = false;
+ break;
+ case Options::kCommonsConflictsDylibsError:
+ throwf("common symbol %s from %s conflicts with defintion from dylib %s",
+ newAtom.getName(), newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
+ }
+ break;
+ case kExternAndExtern:
+ throwf("duplicate symbol %s in %s and %s\n", name, newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
+ case kExternAndExternWeak:
+ // keep strong dylib atom, ignore weak one
+ useNew = false;
+ break;
+ case kExternAndAbsolute:
+ // replace external atom with absolute one
+ break;
+ case kExternWeakAndReg:
+ // replace existing weak external with regular
+ break;
+ case kExternWeakAndWeak:
+ // replace existing weak external with weak (let dyld decide at runtime which to use)
+ break;
+ case kExternWeakAndTent:
+ // a tentative definition and a dylib definition, so commons-mode decides how to handle
+ switch ( fOwner.fOptions.commonsMode() ) {
+ case Options::kCommonsIgnoreDylibs:
+ if ( fOwner.fOptions.warnCommons() )
+ warning("using common symbol %s from %s and ignoring defintion from dylib %s",
+ newAtom.getName(), newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
+ break;
+ case Options::kCommonsOverriddenByDylibs:
+ if ( fOwner.fOptions.warnCommons() )
+ warning("replacing defintion of %s from dylib %s with common symbol from %s",
+ newAtom.getName(), existingAtom->getFile()->getPath(), newAtom.getFile()->getPath());
+ useNew = false;
+ break;
+ case Options::kCommonsConflictsDylibsError:
+ throwf("common symbol %s from %s conflicts with defintion from dylib %s",
+ newAtom.getName(), newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
+ }
+ break;
+ case kExternWeakAndExtern:
+ // replace existing weak external with external
+ break;
+ case kExternWeakAndExternWeak:
+ // keep existing external weak
+ useNew = false;
+ break;
+ case kExternWeakAndAbsolute:
+ // replace existing weak external with absolute
+ break;
+ case kAbsoluteAndReg:
+ throwf("duplicate symbol %s in %s and %s", name, newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
+ case kAbsoluteAndWeak:
+ // ignore new weak atom, because we already have a non-weak one
+ useNew = false;
+ break;
+ case kAbsoluteAndTent:
+ // ignore new tentative atom, because we already have a regular one
+ useNew = false;
+ break;
+ case kAbsoluteAndExtern:
+ // ignore external atom, because we already have a one
+ useNew = false;
+ break;
+ case kAbsoluteAndExternWeak:
+ // ignore external atom, because we already have a one
+ useNew = false;
+ break;
+ case kAbsoluteAndAbsolute:
+ throwf("duplicate symbol %s in %s and %s", name, newAtom.getFile()->getPath(), existingAtom->getFile()->getPath());
+ break;
+ }
+ }
+ if ( (existingAtom != NULL) && checkVisibilityMismatch && (newAtom.getScope() != existingAtom->getScope()) ) {
+ warning("%s has different visibility (%s) in %s and (%s) in %s",
+ newAtom.getDisplayName(), (newAtom.getScope() == 1 ? "hidden" : "default"), newAtom.getFile()->getPath(), (existingAtom->getScope() == 1 ? "hidden" : "default"), existingAtom->getFile()->getPath());
+ }
+ if ( useNew ) {
+ fTable[name] = &newAtom;
+ if ( existingAtom != NULL ) {
+ fOwner.markDead(existingAtom);
+ if ( fOwner.fInitialLoadsDone ) {
+ //fprintf(stderr, "existing %p %s overridden by %p\n", existingAtom, existingAtom->getName(), &newAtom);
+ fOwner.fAtomsOverriddenByLateLoads.insert(existingAtom);
+ }
+ }
+ if ( newAtom.getScope() == ObjectFile::Atom::scopeGlobal ) {
+ switch ( newAtom.getDefinitionKind() ) {
+ case ObjectFile::Atom::kTentativeDefinition:
+ fHasExternalTentativeDefinitions = true;
+ ++fRequireCount; // added a tentative definition means loadUndefines() needs to continue
+ break;
+ case ObjectFile::Atom::kWeakDefinition:
+ fHasExternalWeakDefinitions = true;
+ break;
+ default:
+ break;
+ }
+ }
+ }
+ else {
+ fOwner.markDead(&newAtom);
+ }
+ return useNew;
+}
+
+
+
+ObjectFile::Atom* Linker::SymbolTable::find(const char* name)
+{
+ Mapper::iterator pos = fTable.find(name);
+ if ( pos != fTable.end() ) {
+ return pos->second;
+ }
+ return NULL;
+}
+
+
+void Linker::SymbolTable::getUndefinesNames(std::vector<const char*>& undefines)
+{
+ for (Mapper::iterator it=fTable.begin(); it != fTable.end(); it++) {
+ if ( it->second == NULL ) {
+ undefines.push_back(it->first);
+ }
+ }
+}
+
+void Linker::SymbolTable::getTentativesNames(std::vector<const char*>& tents)
+{
+ for (Mapper::iterator it=fTable.begin(); it != fTable.end(); it++) {
+ if ( it->second != NULL ) {
+ if ( (it->second->getDefinitionKind() == ObjectFile::Atom::kTentativeDefinition)
+ && (it->second->getScope() == ObjectFile::Atom::scopeGlobal) ) {
+ tents.push_back(it->first);
+ }
+ }
+ }
+}
+
+
+
+bool Linker::AtomSorter::operator()(const ObjectFile::Atom* left, const ObjectFile::Atom* right)
+{
+ if ( left == right )
+ return false;
+
+ // first sort by section order (which is already sorted by segment)
+ unsigned int leftSectionIndex = left->getSection()->getIndex();
+ unsigned int rightSectionIndex = right->getSection()->getIndex();
+ if ( leftSectionIndex != rightSectionIndex)
+ return (leftSectionIndex < rightSectionIndex);
+
+ // if a -order_file is specified, then sorting is altered to sort those symbols first
+ if ( fOverriddenOrdinalMap != NULL ) {
+ std::map<const ObjectFile::Atom*, uint32_t>::iterator leftPos = fOverriddenOrdinalMap->find(left);
+ std::map<const ObjectFile::Atom*, uint32_t>::iterator rightPos = fOverriddenOrdinalMap->find(right);
+ std::map<const ObjectFile::Atom*, uint32_t>::iterator end = fOverriddenOrdinalMap->end();
+ if ( leftPos != end ) {
+ if ( rightPos != end ) {
+ // both left and right are overridden, so compare overridden ordinals
+ return leftPos->second < rightPos->second;
+ }
+ else {
+ // left is overridden and right is not, so left < right
+ return true;
+ }
+ }
+ else {
+ if ( rightPos != end ) {
+ // right is overridden and left is not, so right < left
+ return false;
+ }
+ else {
+ // neither are overridden, do default sort
+ // fall into default sorting below
+ }
+ }
+ }
+
+ // the __common section can have real or tentative definitions
+ // we want the real ones to sort before tentative ones
+ bool leftIsTent = (left->getDefinitionKind() == ObjectFile::Atom::kTentativeDefinition);
+ bool rightIsTent = (right->getDefinitionKind() == ObjectFile::Atom::kTentativeDefinition);
+ if ( leftIsTent != rightIsTent )
+ return rightIsTent;
+
+ // initializers are auto sorted to start of section
+ if ( !fInitializerSet.empty() ) {
+ bool leftFirst = (fInitializerSet.count(left) != 0);
+ bool rightFirst = (fInitializerSet.count(right) != 0);
+ if ( leftFirst != rightFirst )
+ return leftFirst;
+ }
+
+ // terminators are auto sorted to end of section
+ if ( !fTerminatorSet.empty() ) {
+ bool leftLast = (fTerminatorSet.count(left) != 0);
+ bool rightLast = (fTerminatorSet.count(right) != 0);
+ if ( leftLast != rightLast )
+ return rightLast;
+ }
+
+ // lastly sort by atom ordinal. this is already sorted by .o order
+ return left->getOrdinal() < right->getOrdinal();
+}
+
+
+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