X-Git-Url: https://git.saurik.com/apple/ld64.git/blobdiff_plain/b2fa67a80bc53211e4d1ea81f23e9f953ee1dd6c..599556ff3dd31aab68bb9685f1ed7fc4867803e7:/src/ld/Resolver.cpp diff --git a/src/ld/Resolver.cpp b/src/ld/Resolver.cpp index 2502820..a5405a9 100644 --- a/src/ld/Resolver.cpp +++ b/src/ld/Resolver.cpp @@ -47,8 +47,6 @@ #include #include #include -#include -#include #include #include @@ -80,8 +78,6 @@ public: _name(nm) {} // overrides of ld::Atom virtual const ld::File* file() const { return NULL; } - virtual bool translationUnitSource(const char** dir, const char** nm) const - { return false; } virtual const char* name() const { return _name; } virtual uint64_t size() const { return 0; } virtual uint64_t objectAddress() const { return 0; } @@ -116,8 +112,8 @@ public: // overrides of ld::Atom virtual const ld::File* file() const { return _aliasOf.file(); } - virtual bool translationUnitSource(const char** dir, const char** nm) const - { return _aliasOf.translationUnitSource(dir, nm); } + virtual const char* translationUnitSource() const + { return _aliasOf.translationUnitSource(); } virtual const char* name() const { return _name; } virtual uint64_t size() const { return 0; } virtual uint64_t objectAddress() const { return _aliasOf.objectAddress(); } @@ -133,6 +129,11 @@ public: virtual ld::Atom::UnwindInfo::iterator endUnwind() const { return NULL; } virtual ld::Atom::LineInfo::iterator beginLineInfo() const { return NULL; } virtual ld::Atom::LineInfo::iterator endLineInfo() const { return NULL; } + + void setFinalAliasOf() const { + (const_cast(this))->setAttributesFromAtom(_aliasOf); + (const_cast(this))->setScope(ld::Atom::scopeGlobal); + } private: const char* _name; @@ -149,8 +150,6 @@ public: static SectionBoundaryAtom* makeOldSectionBoundaryAtom(const char* name, bool start); // overrides of ld::Atom - virtual bool translationUnitSource(const char** dir, const char** nm) const - { return false; } virtual const ld::File* file() const { return NULL; } virtual const char* name() const { return _name; } virtual uint64_t size() const { return 0; } @@ -215,8 +214,6 @@ public: static SegmentBoundaryAtom* makeOldSegmentBoundaryAtom(const char* name, bool start); // overrides of ld::Atom - virtual bool translationUnitSource(const char** dir, const char** nm) const - { return false; } virtual const ld::File* file() const { return NULL; } virtual const char* name() const { return _name; } virtual uint64_t size() const { return 0; } @@ -285,25 +282,82 @@ void Resolver::initializeState() _internal.objcObjectConstraint = ld::File::objcConstraintGC; _internal.cpuSubType = _options.subArchitecture(); + + // In -r mode, look for -linker_option additions + if ( _options.outputKind() == Options::kObjectFile ) { + ld::relocatable::File::LinkerOptionsList lo = _options.linkerOptions(); + for (relocatable::File::LinkerOptionsList::const_iterator it=lo.begin(); it != lo.end(); ++it) { + doLinkerOption(*it, "command line"); + } + } } void Resolver::buildAtomList() { // each input files contributes initial atoms _atoms.reserve(1024); - _inputFiles.forEachInitialAtom(*this); + _inputFiles.forEachInitialAtom(*this, _internal); + _completedInitialObjectFiles = true; //_symbolTable.printStatistics(); } +void Resolver::doLinkerOption(const std::vector& linkerOption, const char* fileName) +{ + if ( linkerOption.size() == 1 ) { + const char* lo1 = linkerOption.front(); + if ( strncmp(lo1, "-l", 2) == 0 ) { + _internal.linkerOptionLibraries.insert(&lo1[2]); + } + else { + warning("unknown linker option from object file ignored: '%s' in %s", lo1, fileName); + } + } + else if ( linkerOption.size() == 2 ) { + const char* lo2a = linkerOption[0]; + const char* lo2b = linkerOption[1]; + if ( strcmp(lo2a, "-framework") == 0 ) { + _internal.linkerOptionFrameworks.insert(lo2b); + } + else { + warning("unknown linker option from object file ignored: '%s' '%s' from %s", lo2a, lo2b, fileName); + } + } + else { + warning("unknown linker option from object file ignored, starting with: '%s' from %s", linkerOption.front(), fileName); + } +} + +static void userReadableSwiftVersion(uint8_t value, char versionString[64]) +{ + switch (value) { + case 1: + strcpy(versionString, "1.0"); + break; + case 2: + strcpy(versionString, "1.1"); + break; + default: + sprintf(versionString, "unknown ABI version 0x%02X", value); + } +} + void Resolver::doFile(const ld::File& file) { const ld::relocatable::File* objFile = dynamic_cast(&file); const ld::dylib::File* dylibFile = dynamic_cast(&file); if ( objFile != NULL ) { + // if file has linker options, process them + ld::relocatable::File::LinkerOptionsList* lo = objFile->linkerOptions(); + if ( lo != NULL ) { + for (relocatable::File::LinkerOptionsList::const_iterator it=lo->begin(); it != lo->end(); ++it) { + this->doLinkerOption(*it, file.path()); + } + } + // update which form of ObjC is being used switch ( file.objCConstraint() ) { case ld::File::objcConstraintNone: @@ -315,27 +369,59 @@ void Resolver::doFile(const ld::File& file) throwf("command line specified -objc_gc_only, but file is retain/release based: %s", file.path()); if ( _options.objcGc() ) throwf("command line specified -objc_gc, but file is retain/release based: %s", file.path()); - _internal.objcObjectConstraint = ld::File::objcConstraintRetainRelease; + if ( !_options.targetIOSSimulator() && (_internal.objcObjectConstraint != ld::File::objcConstraintRetainReleaseForSimulator) ) + _internal.objcObjectConstraint = ld::File::objcConstraintRetainRelease; break; case ld::File::objcConstraintRetainReleaseOrGC: if ( _internal.objcObjectConstraint == ld::File::objcConstraintNone ) _internal.objcObjectConstraint = ld::File::objcConstraintRetainReleaseOrGC; + if ( _options.targetIOSSimulator() ) + warning("linking ObjC for iOS Simulator, but object file (%s) was compiled for MacOSX", file.path()); break; case ld::File::objcConstraintGC: if ( _internal.objcObjectConstraint == ld::File::objcConstraintRetainRelease ) throwf("%s built with incompatible Garbage Collection settings to link with previous .o files", file.path()); _internal.objcObjectConstraint = ld::File::objcConstraintGC; + if ( _options.targetIOSSimulator() ) + warning("linking ObjC for iOS Simulator, but object file (%s) was compiled for MacOSX", file.path()); + break; + case ld::File::objcConstraintRetainReleaseForSimulator: + if ( _internal.objcObjectConstraint == ld::File::objcConstraintNone ) { + if ( !_options.targetIOSSimulator() && (_options.outputKind() != Options::kObjectFile) ) + warning("ObjC object file (%s) was compiled for iOS Simulator, but linking for MacOSX", file.path()); + _internal.objcObjectConstraint = ld::File::objcConstraintRetainReleaseForSimulator; + } + else if ( _internal.objcObjectConstraint != ld::File::objcConstraintRetainReleaseForSimulator ) { + _internal.objcObjectConstraint = ld::File::objcConstraintRetainReleaseForSimulator; + } break; } + // verify all files use same version of Swift language + if ( file.swiftVersion() != 0 ) { + if ( _internal.swiftVersion == 0 ) { + _internal.swiftVersion = file.swiftVersion(); + } + else if ( file.swiftVersion() != _internal.swiftVersion ) { + char fileVersion[64]; + char otherVersion[64]; + userReadableSwiftVersion(file.swiftVersion(), fileVersion); + userReadableSwiftVersion(_internal.swiftVersion, otherVersion); + if ( file.swiftVersion() > _internal.swiftVersion ) { + throwf("%s compiled with newer version of Swift language (%s) than previous files (%s)", + file.path(), fileVersion, otherVersion); + } + else { + throwf("%s compiled with older version of Swift language (%s) than previous files (%s)", + file.path(), fileVersion, otherVersion); + } + } + } + // in -r mode, if any .o files have dwarf then add UUID to output .o file if ( objFile->debugInfo() == ld::relocatable::File::kDebugInfoDwarf ) _internal.someObjectFileHasDwarf = true; - // remember if any objc classes built for fix-and-continue - if ( objFile->objcReplacementClasses() ) - _internal.hasObjcReplacementClasses = true; - // remember if any .o file did not have MH_SUBSECTIONS_VIA_SYMBOLS bit set if ( ! objFile->canScatterAtoms() ) _internal.allObjectFilesScatterable = false; @@ -367,7 +453,16 @@ void Resolver::doFile(const ld::File& file) break; case CPU_TYPE_X86_64: - _internal.cpuSubType = CPU_SUBTYPE_X86_64_ALL; + if ( _options.subArchitecture() != nextObjectSubType ) { + if ( _options.allowSubArchitectureMismatches() ) { + warning("object file %s was built for different x86_64 sub-type (%d) than link command line (%d)", + file.path(), nextObjectSubType, _options.subArchitecture()); + } + else { + throwf("object file %s was built for different x86_64 sub-type (%d) than link command line (%d)", + file.path(), nextObjectSubType, _options.subArchitecture()); + } + } break; } } @@ -383,17 +478,52 @@ void Resolver::doFile(const ld::File& file) throwf("command line specified -objc_gc_only, but dylib is retain/release based: %s", file.path()); if ( _options.objcGc() ) throwf("command line specified -objc_gc, but dylib is retain/release based: %s", file.path()); + if ( _options.targetIOSSimulator() ) + warning("linking ObjC for iOS Simulator, but dylib (%s) was compiled for MacOSX", file.path()); _internal.objcDylibConstraint = ld::File::objcConstraintRetainRelease; break; case ld::File::objcConstraintRetainReleaseOrGC: if ( _internal.objcDylibConstraint == ld::File::objcConstraintNone ) _internal.objcDylibConstraint = ld::File::objcConstraintRetainReleaseOrGC; + if ( _options.targetIOSSimulator() ) + warning("linking ObjC for iOS Simulator, but dylib (%s) was compiled for MacOSX", file.path()); break; case ld::File::objcConstraintGC: if ( _internal.objcDylibConstraint == ld::File::objcConstraintRetainRelease ) throwf("%s built with incompatible Garbage Collection settings to link with previous dylibs", file.path()); - _internal.objcDylibConstraint = ld::File::objcConstraintGC; + if ( _options.targetIOSSimulator() ) + warning("linking ObjC for iOS Simulator, but dylib (%s) was compiled for MacOSX", file.path()); + _internal.objcDylibConstraint = ld::File::objcConstraintGC; break; + case ld::File::objcConstraintRetainReleaseForSimulator: + if ( _internal.objcDylibConstraint == ld::File::objcConstraintNone ) + _internal.objcDylibConstraint = ld::File::objcConstraintRetainReleaseForSimulator; + else if ( _internal.objcDylibConstraint != ld::File::objcConstraintRetainReleaseForSimulator ) { + warning("ObjC dylib (%s) was compiled for iOS Simulator, but dylibs others were compiled for MacOSX", file.path()); + _internal.objcDylibConstraint = ld::File::objcConstraintRetainReleaseForSimulator; + } + break; + } + if ( _options.checkDylibsAreAppExtensionSafe() && !dylibFile->appExtensionSafe() ) { + warning("linking against dylib not safe for use in application extensions: %s", file.path()); + } + const char* depInstallName = dylibFile->installPath(); + // embedded frameworks are only supported on iOS 8 and later + if ( (depInstallName != NULL) && (depInstallName[0] != '/') ) { + if ( (_options.iOSVersionMin() != iOSVersionUnset) && (_options.iOSVersionMin() < iOS_8_0) ) { + // only warn about linking against embedded dylib if it is built for iOS 8 or later + if ( dylibFile->iOSMinVersion() >= iOS_8_0 ) + throwf("embedded dylibs/frameworks are only supported on iOS 8.0 and later (%s)", depInstallName); + } + } + if ( _options.sharedRegionEligible() ) { + assert(depInstallName != NULL); + if ( depInstallName[0] == '@' ) + warning("invalid -install_name (%s) in dependent dylib (%s). Dylibs/frameworks which might go in dyld shared cache " + "cannot link with dylib that uses @rpath, @loaderpath, etc.", depInstallName, dylibFile->path()); + if ( (strncmp(depInstallName, "/usr/lib/", 9) != 0) && (strncmp(depInstallName, "/System/Library/", 16) != 0) ) + warning("invalid -install_name (%s) in dependent dylib (%s). Dylibs/frameworks which might go in dyld shared cache " + "cannot link with dylibs that won't be in the shared cache", depInstallName, dylibFile->path()); } } @@ -401,7 +531,9 @@ void Resolver::doFile(const ld::File& file) void Resolver::doAtom(const ld::Atom& atom) { - //fprintf(stderr, "Resolver::doAtom(%p), name=%s, sect=%s\n", &atom, atom.name(), atom.section().sectionName()); + //fprintf(stderr, "Resolver::doAtom(%p), name=%s, sect=%s, scope=%d\n", &atom, atom.name(), atom.section().sectionName(), atom.scope()); + if ( _ltoCodeGenFinished && (atom.contentType() == ld::Atom::typeLTOtemporary) && (atom.scope() != ld::Atom::scopeTranslationUnit) ) + warning("'%s' is implemented in bitcode, but it was loaded too late", atom.name()); // add to list of known atoms _atoms.push_back(&atom); @@ -427,16 +559,16 @@ void Resolver::doAtom(const ld::Atom& atom) } else if ( _options.outputKind() == Options::kDynamicLibrary ) { if ( atom.file() != NULL ) - warning("target OS does not support re-exporting symbol %s from %s\n", SymbolTable::demangle(name), atom.file()->path()); + warning("target OS does not support re-exporting symbol %s from %s\n", _options.demangleSymbol(name), atom.file()->path()); else - warning("target OS does not support re-exporting symbol %s\n", SymbolTable::demangle(name)); + warning("target OS does not support re-exporting symbol %s\n", _options.demangleSymbol(name)); } } else { if ( atom.file() != NULL ) - warning("cannot export hidden symbol %s from %s", SymbolTable::demangle(name), atom.file()->path()); + warning("cannot export hidden symbol %s from %s", _options.demangleSymbol(name), atom.file()->path()); else - warning("cannot export hidden symbol %s", SymbolTable::demangle(name)); + warning("cannot export hidden symbol %s", _options.demangleSymbol(name)); } } } @@ -446,7 +578,7 @@ void Resolver::doAtom(const ld::Atom& atom) (const_cast(&atom))->setScope(ld::Atom::scopeGlobal); } else { - throwf("requested re-export symbol %s is not from a dylib, but from %s\n", SymbolTable::demangle(name), atom.file()->path()); + throwf("requested re-export symbol %s is not from a dylib, but from %s\n", _options.demangleSymbol(name), atom.file()->path()); } } break; @@ -457,7 +589,7 @@ void Resolver::doAtom(const ld::Atom& atom) //fprintf(stderr, "demote %s to hidden\n", name); } if ( _options.canReExportSymbols() && _options.shouldReExport(name) ) { - throwf("requested re-export symbol %s is not from a dylib, but from %s\n", SymbolTable::demangle(name), atom.file()->path()); + throwf("requested re-export symbol %s is not from a dylib, but from %s\n", _options.demangleSymbol(name), atom.file()->path()); } break; } @@ -465,7 +597,8 @@ void Resolver::doAtom(const ld::Atom& atom) // work around for kernel that uses 'l' labels in assembly code if ( (atom.symbolTableInclusion() == ld::Atom::symbolTableNotInFinalLinkedImages) - && (atom.name()[0] == 'l') && (_options.outputKind() == Options::kStaticExecutable) ) + && (atom.name()[0] == 'l') && (_options.outputKind() == Options::kStaticExecutable) + && (strncmp(atom.name(), "ltmp", 4) != 0) ) (const_cast(&atom))->setSymbolTableInclusion(ld::Atom::symbolTableIn); @@ -478,7 +611,8 @@ void Resolver::doAtom(const ld::Atom& atom) const std::vector& aliases = _options.cmdLineAliases(); for (std::vector::const_iterator it=aliases.begin(); it != aliases.end(); ++it) { if ( strcmp(it->realName, atom.name()) == 0 ) { - const ld::Atom* alias = new AliasAtom(atom, it->alias); + const AliasAtom* alias = new AliasAtom(atom, it->alias); + _aliasesFromCmdLine.push_back(alias); this->doAtom(*alias); } } @@ -492,9 +626,9 @@ void Resolver::doAtom(const ld::Atom& atom) if ( atom.contentType() == ld::Atom::typeLTOtemporary ) _haveLLVMObjs = true; - // if we've already partitioned into final sections, and lto needs a symbol very late, add it - if ( _addToFinalSection ) - _internal.addAtom(atom); + // remember if any atoms are aliases + if ( atom.section().type() == ld::Section::typeTempAlias ) + _haveAliases = true; if ( _options.deadCodeStrip() ) { // add to set of dead-strip-roots, all symbols that the compiler marks as don't strip @@ -519,6 +653,8 @@ bool Resolver::isDtraceProbe(ld::Fixup::Kind kind) case ld::Fixup::kindStoreX86DtraceIsEnableSiteClear: case ld::Fixup::kindStoreARMDtraceCallSiteNop: case ld::Fixup::kindStoreARMDtraceIsEnableSiteClear: + case ld::Fixup::kindStoreARM64DtraceCallSiteNop: + case ld::Fixup::kindStoreARM64DtraceIsEnableSiteClear: case ld::Fixup::kindStoreThumbDtraceCallSiteNop: case ld::Fixup::kindStoreThumbDtraceIsEnableSiteClear: case ld::Fixup::kindDtraceExtra: @@ -536,6 +672,8 @@ void Resolver::convertReferencesToIndirect(const ld::Atom& atom) const ld::Atom* dummy; ld::Fixup::iterator end = atom.fixupsEnd(); for (ld::Fixup::iterator fit=atom.fixupsBegin(); fit != end; ++fit) { + if ( fit->kind == ld::Fixup::kindLinkerOptimizationHint ) + _internal.someObjectHasOptimizationHints = true; switch ( fit->binding ) { case ld::Fixup::bindingByNameUnbound: if ( isDtraceProbe(fit->kind) && (_options.outputKind() != Options::kObjectFile ) ) { @@ -647,14 +785,34 @@ void Resolver::resolveUndefines() } } } - + + // Use linker options to resolve any remaining undefined symbols + if ( !_internal.linkerOptionLibraries.empty() || !_internal.linkerOptionFrameworks.empty() ) { + std::vector undefineNames; + _symbolTable.undefines(undefineNames); + if ( undefineNames.size() != 0 ) { + for (std::vector::iterator it = undefineNames.begin(); it != undefineNames.end(); ++it) { + const char* undef = *it; + if ( ! _symbolTable.hasName(undef) ) { + _inputFiles.searchLibraries(undef, true, true, false, *this); + } + } + } + } + // create proxies as needed for undefined symbols if ( (_options.undefinedTreatment() != Options::kUndefinedError) || (_options.outputKind() == Options::kObjectFile) ) { std::vector undefineNames; _symbolTable.undefines(undefineNames); for(std::vector::iterator it = undefineNames.begin(); it != undefineNames.end(); ++it) { - // make proxy - this->doAtom(*new UndefinedProxyAtom(*it)); + const char* undefName = *it; + // "ld -r -exported_symbol _foo" has wrong error message if _foo is undefined + bool makeProxy = true; + if ( (_options.outputKind() == Options::kObjectFile) && _options.hasExportMaskList() && _options.shouldExport(undefName) ) + makeProxy = false; + + if ( makeProxy ) + this->doAtom(*new UndefinedProxyAtom(undefName)); } } @@ -706,6 +864,7 @@ void Resolver::markLive(const ld::Atom& atom, WhyLiveBackChain* previous) case ld::Fixup::kindNoneGroupSubordinate: case ld::Fixup::kindNoneGroupSubordinateFDE: case ld::Fixup::kindNoneGroupSubordinateLSDA: + case ld::Fixup::kindNoneGroupSubordinatePersonality: case ld::Fixup::kindSetTargetAddress: case ld::Fixup::kindSubtractTargetAddress: case ld::Fixup::kindStoreTargetAddressLittleEndian32: @@ -722,6 +881,12 @@ void Resolver::markLive(const ld::Atom& atom, WhyLiveBackChain* previous) case ld::Fixup::kindStoreTargetAddressX86Abs32TLVLoadNowLEA: case ld::Fixup::kindStoreTargetAddressARMBranch24: case ld::Fixup::kindStoreTargetAddressThumbBranch22: +#if SUPPORT_ARCH_arm64 + case ld::Fixup::kindStoreTargetAddressARM64Branch26: + case ld::Fixup::kindStoreTargetAddressARM64Page21: + case ld::Fixup::kindStoreTargetAddressARM64GOTLoadPage21: + case ld::Fixup::kindStoreTargetAddressARM64GOTLeaPage21: +#endif if ( fit->binding == ld::Fixup::bindingByContentBound ) { // normally this was done in convertReferencesToIndirect() // but a archive loaded .o file may have a forward reference @@ -801,7 +966,7 @@ public: } }; -void Resolver::deadStripOptimize() +void Resolver::deadStripOptimize(bool force) { // only do this optimization with -dead_strip if ( ! _options.deadCodeStrip() ) @@ -856,22 +1021,71 @@ void Resolver::deadStripOptimize() // now remove all non-live atoms from _atoms const bool log = false; if ( log ) { - fprintf(stderr, "deadStripOptimize() all atoms with liveness:\n"); + fprintf(stderr, "deadStripOptimize() all %ld atoms with liveness:\n", _atoms.size()); for (std::vector::const_iterator it=_atoms.begin(); it != _atoms.end(); ++it) { - fprintf(stderr, " live=%d name=%s\n", (*it)->live(), (*it)->name()); + const ld::File* file = (*it)->file(); + fprintf(stderr, " live=%d atom=%p name=%s from=%s\n", (*it)->live(), *it, (*it)->name(), (file ? file->path() : "")); } } - if ( _haveLLVMObjs ) { + if ( _haveLLVMObjs && !force ) { // don't remove combinable atoms, they may come back in lto output _atoms.erase(std::remove_if(_atoms.begin(), _atoms.end(), NotLiveLTO()), _atoms.end()); + _symbolTable.removeDeadAtoms(); } else { _atoms.erase(std::remove_if(_atoms.begin(), _atoms.end(), NotLive()), _atoms.end()); } + + if ( log ) { + fprintf(stderr, "deadStripOptimize() %ld remaining atoms\n", _atoms.size()); + for (std::vector::const_iterator it=_atoms.begin(); it != _atoms.end(); ++it) { + fprintf(stderr, " live=%d atom=%p name=%s\n", (*it)->live(), *it, (*it)->name()); + } + } } +// This is called when LTO is used but -dead_strip is not used. +// Some undefines were eliminated by LTO, but others were not. +void Resolver::remainingUndefines(std::vector& undefs) +{ + StringSet undefSet; + // search all atoms for references that are unbound + for (std::vector::const_iterator it=_atoms.begin(); it != _atoms.end(); ++it) { + const ld::Atom* atom = *it; + for (ld::Fixup::iterator fit=atom->fixupsBegin(); fit != atom->fixupsEnd(); ++fit) { + switch ( (ld::Fixup::TargetBinding)fit->binding ) { + case ld::Fixup::bindingByNameUnbound: + assert(0 && "should not be by-name this late"); + undefSet.insert(fit->u.name); + break; + case ld::Fixup::bindingsIndirectlyBound: + if ( _internal.indirectBindingTable[fit->u.bindingIndex] == NULL ) { + undefSet.insert(_symbolTable.indirectName(fit->u.bindingIndex)); + } + break; + case ld::Fixup::bindingByContentBound: + case ld::Fixup::bindingNone: + case ld::Fixup::bindingDirectlyBound: + break; + } + } + } + // look for any initial undefines that are still undefined + for (Options::UndefinesIterator uit=_options.initialUndefinesBegin(); uit != _options.initialUndefinesEnd(); ++uit) { + if ( ! _symbolTable.hasName(*uit) ) { + undefSet.insert(*uit); + } + } + + // copy set to vector + for (StringSet::const_iterator it=undefSet.begin(); it != undefSet.end(); ++it) { + fprintf(stderr, "undef: %s\n", *it); + undefs.push_back(*it); + } +} + void Resolver::liveUndefines(std::vector& undefs) { StringSet undefSet; @@ -990,7 +1204,7 @@ bool Resolver::printReferencedBy(const char* name, SymbolTable::IndirectBindingS ++foundReferenceCount; } else { - fprintf(stderr, " %s in %s\n", SymbolTable::demangle(atom->name()), pathLeafName(atom->file()->path())); + fprintf(stderr, " %s in %s\n", _options.demangleSymbol(atom->name()), pathLeafName(atom->file()->path())); ++foundReferenceCount; break; // if undefined used twice in a function, only show first } @@ -1029,9 +1243,10 @@ void Resolver::checkUndefines(bool force) break; } std::vector unresolvableUndefines; - // LTO many have eliminated need for some undefines - if ( _options.deadCodeStrip() || _haveLLVMObjs ) + if ( _options.deadCodeStrip() ) this->liveUndefines(unresolvableUndefines); + else if( _haveLLVMObjs ) + this->remainingUndefines(unresolvableUndefines); // LTO may have eliminated need for some undefines else _symbolTable.undefines(unresolvableUndefines); @@ -1056,7 +1271,7 @@ void Resolver::checkUndefines(bool force) for (int i=0; i < unresolvableCount; ++i) { const char* name = unresolvableUndefines[i]; unsigned int slot = _symbolTable.findSlotForName(name); - fprintf(stderr, " \"%s\", referenced from:\n", SymbolTable::demangle(name)); + fprintf(stderr, " \"%s\", referenced from:\n", _options.demangleSymbol(name)); // scan all atoms for references bool foundAtomReference = printReferencedBy(name, slot); // scan command line options @@ -1073,6 +1288,10 @@ void Resolver::checkUndefines(bool force) else if ( _options.hasReExportList() && _options.shouldReExport(name) ) { fprintf(stderr, " -reexported_symbols_list command line option\n"); } + else if ( (_options.outputKind() == Options::kDynamicExecutable) + && (_options.entryName() != NULL) && (strcmp(name, _options.entryName()) == 0) ) { + fprintf(stderr, " implicit entry/start for main executable\n"); + } else { bool isInitialUndefine = false; for (Options::UndefinesIterator uit=_options.initialUndefinesBegin(); uit != _options.initialUndefinesEnd(); ++uit) { @@ -1174,8 +1393,6 @@ const ld::Atom* Resolver::entryPoint(bool searchArchives) else if ( _internal.indirectBindingTable[slot]->definition() == ld::Atom::definitionProxy ) { if ( makingDylib ) throwf("-init function (%s) found in linked dylib, must be in dylib being linked", symbolName); - else - throwf("entry point (%s) found in linked dylib, must be in executable being linked", symbolName); } return _internal.indirectBindingTable[slot]; } @@ -1252,17 +1469,60 @@ void Resolver::fillInInternalState() // make sure there is a __text section so that codesigning works if ( (_options.outputKind() == Options::kDynamicLibrary) || (_options.outputKind() == Options::kDynamicBundle) ) - _internal.getFinalSection(ld::Section("__TEXT", "__text", ld::Section::typeCode)); + _internal.getFinalSection(*new ld::Section("__TEXT", "__text", ld::Section::typeCode)); +} - // add entry point +void Resolver::fillInEntryPoint() +{ _internal.entryPoint = this->entryPoint(true); } - +void Resolver::syncAliases() +{ + if ( !_haveAliases || (_options.outputKind() == Options::kObjectFile) ) + return; + + // Set attributes of alias to match its found target + for (std::vector::iterator it = _atoms.begin(); it != _atoms.end(); ++it) { + const ld::Atom* atom = *it; + if ( atom->section().type() == ld::Section::typeTempAlias ) { + assert(atom->fixupsBegin() != atom->fixupsEnd()); + for (ld::Fixup::iterator fit = atom->fixupsBegin(); fit != atom->fixupsEnd(); ++fit) { + const ld::Atom* target; + ld::Atom::Scope scope; + assert(fit->kind == ld::Fixup::kindNoneFollowOn); + switch ( fit->binding ) { + case ld::Fixup::bindingByNameUnbound: + break; + case ld::Fixup::bindingsIndirectlyBound: + target = _internal.indirectBindingTable[fit->u.bindingIndex]; + assert(target != NULL); + scope = atom->scope(); + (const_cast(atom))->setAttributesFromAtom(*target); + // alias has same attributes as target, except for scope + (const_cast(atom))->setScope(scope); + break; + default: + assert(0 && "internal error: unexpected alias binding"); + } + } + } + } +} void Resolver::removeCoalescedAwayAtoms() { + const bool log = false; + if ( log ) { + fprintf(stderr, "removeCoalescedAwayAtoms() starts with %lu atoms\n", _atoms.size()); + } _atoms.erase(std::remove_if(_atoms.begin(), _atoms.end(), AtomCoalescedAway()), _atoms.end()); + if ( log ) { + fprintf(stderr, "removeCoalescedAwayAtoms() after removing coalesced atoms, %lu remain\n", _atoms.size()); + for (std::vector::const_iterator it=_atoms.begin(); it != _atoms.end(); ++it) { + fprintf(stderr, " atom=%p %s\n", *it, (*it)->name()); + } + } } void Resolver::linkTimeOptimize() @@ -1270,12 +1530,15 @@ void Resolver::linkTimeOptimize() // only do work here if some llvm obj files where loaded if ( ! _haveLLVMObjs ) return; - + + // LTO: Symbol multiply defined error should specify exactly where the symbol is found + _symbolTable.checkDuplicateSymbols(); + // run LLVM lto code-gen lto::OptimizeOptions optOpt; optOpt.outputFilePath = _options.outputFilePath(); optOpt.tmpObjectFilePath = _options.tempLtoObjectPath(); - optOpt.allGlobalsAReDeadStripRoots = _options.allGlobalsAreDeadStripRoots(); + optOpt.preserveAllGlobals = _options.allGlobalsAreDeadStripRoots() || _options.hasExportRestrictList(); optOpt.verbose = _options.verbose(); optOpt.saveTemps = _options.saveTempFiles(); optOpt.pie = _options.positionIndependentExecutable(); @@ -1284,51 +1547,43 @@ void Resolver::linkTimeOptimize() optOpt.relocatable = (_options.outputKind() == Options::kObjectFile); optOpt.allowTextRelocs = _options.allowTextRelocs(); optOpt.linkerDeadStripping = _options.deadCodeStrip(); + optOpt.needsUnwindInfoSection = _options.needsUnwindInfoSection(); + optOpt.keepDwarfUnwind = _options.keepDwarfUnwind(); + optOpt.verboseOptimizationHints = _options.verboseOptimizationHints(); optOpt.arch = _options.architecture(); + optOpt.mcpu = _options.mcpuLTO(); optOpt.llvmOptions = &_options.llvmOptions(); + optOpt.initialUndefines = &_options.initialUndefines(); std::vector newAtoms; std::vector additionalUndefines; - if ( ! lto::optimize(_atoms, _internal, _inputFiles.nextInputOrdinal(), optOpt, *this, newAtoms, additionalUndefines) ) + if ( ! lto::optimize(_atoms, _internal, optOpt, *this, newAtoms, additionalUndefines) ) return; // if nothing done - + _ltoCodeGenFinished = true; // add all newly created atoms to _atoms and update symbol table for(std::vector::iterator it = newAtoms.begin(); it != newAtoms.end(); ++it) this->doAtom(**it); - + // some atoms might have been optimized way (marked coalesced), remove them this->removeCoalescedAwayAtoms(); - - // add new atoms into their final section - for (std::vector::iterator it = newAtoms.begin(); it != newAtoms.end(); ++it) { - _internal.addAtom(**it); - } - // remove temp lto section and move all of its atoms to their final section - ld::Internal::FinalSection* tempLTOsection = NULL; - for (std::vector::iterator sit=_internal.sections.begin(); sit != _internal.sections.end(); ++sit) { - ld::Internal::FinalSection* sect = *sit; - if ( sect->type() == ld::Section::typeTempLTO ) { - tempLTOsection = sect; - // remove temp lto section from final image - _internal.sections.erase(sit); - break; - } - } - // lto atoms now have proper section info, so add to final section - if ( tempLTOsection != NULL ) { - for (std::vector::iterator ait=tempLTOsection->atoms.begin(); ait != tempLTOsection->atoms.end(); ++ait) { - const ld::Atom* atom = *ait; - if ( ! atom->coalescedAway() ) { - this->convertReferencesToIndirect(*atom); - _internal.addAtom(*atom); - } - } + // run through all atoms again and make sure newly codegened atoms have references bound + for (std::vector::const_iterator it=_atoms.begin(); it != _atoms.end(); ++it) + this->convertReferencesToIndirect(**it); + + // adjust section of any new + for (std::vector::const_iterator it=_aliasesFromCmdLine.begin(); it != _aliasesFromCmdLine.end(); ++it) { + const AliasAtom* aliasAtom = *it; + // update fields in AliasAtom to match newly constructed mach-o atom + aliasAtom->setFinalAliasOf(); } + // add any auto-link libraries requested by LTO output to dylibs to search + _inputFiles.addLinkerOptionLibraries(_internal, *this); + _inputFiles.createIndirectDylibs(); + // resolve new undefines (e.g calls to _malloc and _memcpy that llvm compiler conjures up) - _addToFinalSection = true; for(std::vector::iterator uit = additionalUndefines.begin(); uit != additionalUndefines.end(); ++uit) { const char *targetName = *uit; // these symbols may or may not already be in linker's symbol table @@ -1336,7 +1591,6 @@ void Resolver::linkTimeOptimize() _inputFiles.searchLibraries(targetName, true, true, false, *this); } } - _addToFinalSection = false; // if -dead_strip on command line if ( _options.deadCodeStrip() ) { @@ -1345,23 +1599,28 @@ void Resolver::linkTimeOptimize() (const_cast(*it))->setLive((*it)->dontDeadStrip()); } // and re-compute dead code - this->deadStripOptimize(); - - // remove newly dead atoms from each section - for (std::vector::iterator sit=_internal.sections.begin(); sit != _internal.sections.end(); ++sit) { - ld::Internal::FinalSection* sect = *sit; - sect->atoms.erase(std::remove_if(sect->atoms.begin(), sect->atoms.end(), NotLive()), sect->atoms.end()); + this->deadStripOptimize(true); + } + + // if -exported_symbols_list on command line, re-force scope + if ( _options.hasExportMaskList() ) { + for (std::vector::const_iterator it=_atoms.begin(); it != _atoms.end(); ++it) { + const ld::Atom* atom = *it; + if ( atom->scope() == ld::Atom::scopeGlobal ) { + if ( !_options.shouldExport(atom->name()) ) { + (const_cast(atom))->setScope(ld::Atom::scopeLinkageUnit); + } + } } } if ( _options.outputKind() == Options::kObjectFile ) { // if -r mode, add proxies for new undefines (e.g. ___stack_chk_fail) - _addToFinalSection = true; this->resolveUndefines(); - _addToFinalSection = false; } else { // last chance to check for undefines + this->resolveUndefines(); this->checkUndefines(true); // check new code does not override some dylib @@ -1370,6 +1629,47 @@ void Resolver::linkTimeOptimize() } +void Resolver::tweakWeakness() +{ + // Add command line options to control symbol weak-def bit on exported symbols + if ( _options.hasWeakBitTweaks() ) { + for (std::vector::iterator sit = _internal.sections.begin(); sit != _internal.sections.end(); ++sit) { + ld::Internal::FinalSection* sect = *sit; + for (std::vector::iterator ait = sect->atoms.begin(); ait != sect->atoms.end(); ++ait) { + const ld::Atom* atom = *ait; + if ( atom->definition() != ld::Atom::definitionRegular ) + continue; + const char* name = atom->name(); + if ( atom->scope() == ld::Atom::scopeGlobal ) { + if ( atom->combine() == ld::Atom::combineNever ) { + if ( _options.forceWeak(name) ) + (const_cast(atom))->setCombine(ld::Atom::combineByName); + } + else if ( atom->combine() == ld::Atom::combineByName ) { + if ( _options.forceNotWeak(name) ) + (const_cast(atom))->setCombine(ld::Atom::combineNever); + } + } + else { + if ( _options.forceWeakNonWildCard(name) ) + warning("cannot force to be weak, non-external symbol %s", name); + else if ( _options.forceNotWeakNonWildcard(name) ) + warning("cannot force to be not-weak, non-external symbol %s", name); + } + } + } + } +} + +void Resolver::dumpAtoms() +{ + fprintf(stderr, "Resolver all atoms:\n"); + for (std::vector::const_iterator it=_atoms.begin(); it != _atoms.end(); ++it) { + const ld::Atom* atom = *it; + fprintf(stderr, " %p name=%s, def=%d\n", atom, atom->name(), atom->definition()); + } +} + void Resolver::resolve() { this->initializeState(); @@ -1380,9 +1680,13 @@ void Resolver::resolve() this->deadStripOptimize(); this->checkUndefines(); this->checkDylibSymbolCollisions(); + this->syncAliases(); this->removeCoalescedAwayAtoms(); - this->fillInInternalState(); + this->fillInEntryPoint(); this->linkTimeOptimize(); + this->fillInInternalState(); + this->tweakWeakness(); + _symbolTable.checkDuplicateSymbols(); }