X-Git-Url: https://git.saurik.com/apple/ld64.git/blobdiff_plain/b1f7435d66a93f03b77932b3a9ad8a83ce5e1ebc..HEAD:/src/ld/Resolver.cpp?ds=sidebyside diff --git a/src/ld/Resolver.cpp b/src/ld/Resolver.cpp index 588def7..17e00cb 100644 --- a/src/ld/Resolver.cpp +++ b/src/ld/Resolver.cpp @@ -47,19 +47,21 @@ #include #include #include -#include -#include #include #include #include "Options.h" - #include "ld.hpp" +#include "Bitcode.hpp" #include "InputFiles.h" #include "SymbolTable.h" #include "Resolver.h" #include "parsers/lto_file.h" +#include "configure.h" + +#define VAL(x) #x +#define STRINGIFY(x) VAL(x) namespace ld { namespace tool { @@ -131,6 +133,11 @@ 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; @@ -172,7 +179,7 @@ private: SectionBoundaryAtom* SectionBoundaryAtom::makeSectionBoundaryAtom(const char* name, bool start, const char* segSectName) { - + const char* segSectDividor = strrchr(segSectName, '$'); if ( segSectDividor == NULL ) throwf("malformed section$ symbol name: %s", name); @@ -182,8 +189,12 @@ SectionBoundaryAtom* SectionBoundaryAtom::makeSectionBoundaryAtom(const char* na throwf("malformed section$ symbol name: %s", name); char segName[18]; strlcpy(segName, segSectName, segNameLen+1); - - const ld::Section* section = new ld::Section(strdup(segName), sectionName, ld::Section::typeUnclassified); + + ld::Section::Type sectType = ld::Section::typeUnclassified; + if (!strcmp(segName, "__TEXT") && !strcmp(sectionName, "__thread_starts")) + sectType = ld::Section::typeThreadStarts; + + const ld::Section* section = new ld::Section(strdup(segName), sectionName, sectType); return new SectionBoundaryAtom(name, *section, (start ? ld::Atom::typeSectionStart : typeSectionEnd)); } @@ -272,20 +283,27 @@ SegmentBoundaryAtom* SegmentBoundaryAtom::makeOldSegmentBoundaryAtom(const char* void Resolver::initializeState() { - // set initial objc constraint based on command line options - if ( _options.objcGc() ) - _internal.objcObjectConstraint = ld::File::objcConstraintRetainReleaseOrGC; - else if ( _options.objcGcOnly() ) - _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"); + } + } +#ifdef LD64_VERSION_NUM + uint32_t packedNum = Options::parseVersionNumber32(STRINGIFY(LD64_VERSION_NUM)); + uint64_t combined = (uint64_t)TOOL_LD << 32 | packedNum; + _internal.toolsVersions.insert(combined); +#endif } void Resolver::buildAtomList() { // each input files contributes initial atoms _atoms.reserve(1024); - _inputFiles.forEachInitialAtom(*this); + _inputFiles.forEachInitialAtom(*this, _internal); _completedInitialObjectFiles = true; @@ -293,36 +311,143 @@ void Resolver::buildAtomList() } +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) { + if (_internal.linkerOptionLibraries.count(&lo1[2]) == 0) { + _internal.unprocessedLinkerOptionLibraries.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) { + if (_internal.linkerOptionFrameworks.count(lo2b) == 0) { + _internal.unprocessedLinkerOptionFrameworks.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); + } +} + + 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 && !_options.ignoreAutoLink() ) { + for (relocatable::File::LinkerOptionsList::const_iterator it=lo->begin(); it != lo->end(); ++it) { + this->doLinkerOption(*it, file.path()); + } + // process any additional linker-options introduced by this new archive member being loaded + if ( _completedInitialObjectFiles ) { + _inputFiles.addLinkerOptionLibraries(_internal, *this); + _inputFiles.createIndirectDylibs(); + } + } // update which form of ObjC is being used - switch ( file.objCConstraint() ) { - case ld::File::objcConstraintNone: - break; - case ld::File::objcConstraintRetainRelease: - if ( _internal.objcObjectConstraint == ld::File::objcConstraintGC ) - throwf("%s built with incompatible Garbage Collection settings to link with previous .o files", file.path()); - if ( _options.objcGcOnly() ) - 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; - break; - case ld::File::objcConstraintRetainReleaseOrGC: - if ( _internal.objcObjectConstraint == ld::File::objcConstraintNone ) - _internal.objcObjectConstraint = ld::File::objcConstraintRetainReleaseOrGC; - 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; - break; + if ( objFile->hasObjC() ) + _internal.hasObjC = true; + + // Resolve bitcode section in the object file + if ( _options.bundleBitcode() ) { + if ( objFile->getBitcode() == NULL ) { + // Handle the special case for compiler_rt objects. Add the file to the list to be process. + if ( objFile->sourceKind() == ld::relocatable::File::kSourceCompilerArchive ) { + _internal.filesFromCompilerRT.push_back(objFile); + } else if (objFile->sourceKind() != ld::relocatable::File::kSourceLTO ) { + // No bitcode section, figure out if the object file comes from LTO/compiler static library + _options.platforms().forEach(^(ld::Platform platform, uint32_t version, bool &stop) { + switch ( platform ) { + case ld::kPlatform_macOS: + case ld::kPlatform_bridgeOS: + case ld::kPlatform_iOSMac: + case ld::kPlatform_unknown: + warning("all bitcode will be dropped because '%s' was built without bitcode. " + "You must rebuild it with bitcode enabled (Xcode setting ENABLE_BITCODE), obtain an updated library from the vendor, or disable bitcode for this target. ", file.path()); + _internal.filesWithBitcode.clear(); + _internal.dropAllBitcode = true; + break; + case ld::kPlatform_iOS: + case ld::kPlatform_iOSSimulator: + throwf("'%s' does not contain bitcode. " + "You must rebuild it with bitcode enabled (Xcode setting ENABLE_BITCODE), obtain an updated library from the vendor, or disable bitcode for this target.", file.path()); + break; + case ld::kPlatform_watchOS: + case ld::kPlatform_watchOSSimulator: + case ld::kPlatform_tvOS: + case ld::kPlatform_tvOSSimulator: + throwf("'%s' does not contain bitcode. " + "You must rebuild it with bitcode enabled (Xcode setting ENABLE_BITCODE) or obtain an updated library from the vendor", file.path()); + break; + } + }); + } + } else { + // contains bitcode, check if it is just a marker + if ( objFile->getBitcode()->isMarker() ) { + // if -bitcode_verify_bundle is used, check if all the object files participate in the linking have full bitcode embedded. + // error on any marker encountered. + if ( _options.verifyBitcode() ) + throwf("bitcode bundle could not be generated because '%s' was built without full bitcode. " + "All object files and libraries for bitcode must be generated from Xcode Archive or Install build", + objFile->path()); + // update the internal state that marker is encountered. + _internal.embedMarkerOnly = true; + _internal.filesWithBitcode.clear(); + _internal.dropAllBitcode = true; + } else if ( !_internal.dropAllBitcode ) + _internal.filesWithBitcode.push_back(objFile); + } } - + + // verify all files use same version of Swift language + if ( file.swiftVersion() != 0 ) { + _internal.someObjectFileHasSwift = true; + if ( _internal.swiftVersion == 0 ) { + _internal.swiftVersion = file.swiftVersion(); + } + else if ( file.swiftVersion() != _internal.swiftVersion ) { + char fileVersion[64]; + char otherVersion[64]; + Options::userReadableSwiftVersion(file.swiftVersion(), fileVersion); + Options::userReadableSwiftVersion(_internal.swiftVersion, otherVersion); + if ( file.swiftVersion() > _internal.swiftVersion ) { + if ( _options.warnOnSwiftABIVersionMismatches() ) { + warning("%s compiled with newer version of Swift language (%s) than previous files (%s)", + file.path(), fileVersion, otherVersion); + } else { + throwf("%s compiled with newer version of Swift language (%s) than previous files (%s)", + file.path(), fileVersion, otherVersion); + } + } + else { + if ( _options.warnOnSwiftABIVersionMismatches() ) { + warning("%s compiled with older 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; @@ -330,7 +455,29 @@ void Resolver::doFile(const ld::File& file) // remember if any .o file did not have MH_SUBSECTIONS_VIA_SYMBOLS bit set if ( ! objFile->canScatterAtoms() ) _internal.allObjectFilesScatterable = false; - + + // remember if building for profiling (so we don't warn about initializers) + if ( objFile->hasllvmProfiling() ) + _havellvmProfiling = true; + +#if MULTI + // update minOSVersion off all .o files + uint32_t objMinOS = objFile->minOSVersion(); + if ( !objMinOS ) + _internal.objectFileFoundWithNoVersion = true; + if ( (_options.outputKind() == Options::kObjectFile) && (objMinOS > _internal.minOSVersion) ) + _internal.minOSVersion = objMinOS; +#endif + + auto objPlatforms = objFile->platforms(); + if ( (!objPlatforms.empty()) && (_options.outputKind() == Options::kObjectFile) && (_internal.derivedPlatforms.empty()) ) + _internal.derivedPlatforms = objPlatforms; + // update set of known tools used + for (const std::pair& entry : objFile->toolVersions()) { + uint64_t combined = (uint64_t)entry.first << 32 | entry.second; + _internal.toolsVersions.insert(combined); + } + // update cpu-sub-type cpu_subtype_t nextObjectSubType = file.cpuSubType(); switch ( _options.architecture() ) { @@ -353,46 +500,172 @@ void Resolver::doFile(const ld::File& file) } break; + case CPU_TYPE_ARM64: + if ( _options.subArchitecture() != nextObjectSubType ) { + if ( _options.allowSubArchitectureMismatches() ) { + warning("object file %s was built for different arm64 sub-type (%d) than link command line (%d)", + file.path(), nextObjectSubType, _options.subArchitecture()); + } + else { + throwf("object file %s was built for different arm64 sub-type (%d) than link command line (%d)", + file.path(), nextObjectSubType, _options.subArchitecture()); + } + } + break; + case CPU_TYPE_I386: _internal.cpuSubType = CPU_SUBTYPE_I386_ALL; 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; } } if ( dylibFile != NULL ) { - // update which form of ObjC dylibs are being linked - switch ( dylibFile->objCConstraint() ) { - case ld::File::objcConstraintNone: - break; - case ld::File::objcConstraintRetainRelease: - if ( _internal.objcDylibConstraint == ld::File::objcConstraintGC ) - throwf("%s built with incompatible Garbage Collection settings to link with previous dylibs", file.path()); - if ( _options.objcGcOnly() ) - 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()); - _internal.objcDylibConstraint = ld::File::objcConstraintRetainRelease; - break; - case ld::File::objcConstraintRetainReleaseOrGC: - if ( _internal.objcDylibConstraint == ld::File::objcConstraintNone ) - _internal.objcDylibConstraint = ld::File::objcConstraintRetainReleaseOrGC; - 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; - break; + // Check dylib for bitcode, if the library install path is relative path or @rpath, it has to contain bitcode + if ( _options.bundleBitcode() ) { + bool isSystemFramework = ( dylibFile->installPath() != NULL ) && ( dylibFile->installPath()[0] == '/' ); + if ( dylibFile->getBitcode() == NULL && !isSystemFramework ) { + // Check if the dylib is from toolchain by checking the path + char tcLibPath[PATH_MAX]; + char ldPath[PATH_MAX]; + char tempPath[PATH_MAX]; + uint32_t bufSize = PATH_MAX; + // toolchain library path should pointed to *.xctoolchain/usr/lib + if ( _NSGetExecutablePath(ldPath, &bufSize) != -1 ) { + if ( realpath(ldPath, tempPath) != NULL ) { + char* lastSlash = strrchr(tempPath, '/'); + if ( lastSlash != NULL ) + strcpy(lastSlash, "/../lib"); + } + } + // Compare toolchain library path to the dylib path + if ( realpath(tempPath, tcLibPath) == NULL || + realpath(dylibFile->path(), tempPath) == NULL || + strncmp(tcLibPath, tempPath, strlen(tcLibPath)) != 0 ) { + _options.platforms().forEach(^(ld::Platform platform, uint32_t version, bool &stop) { + switch ( platform ) { + case ld::kPlatform_macOS: + case ld::kPlatform_bridgeOS: + case ld::kPlatform_iOSMac: + case ld::kPlatform_unknown: + warning("all bitcode will be dropped because '%s' was built without bitcode. " + "You must rebuild it with bitcode enabled (Xcode setting ENABLE_BITCODE), obtain an updated library from the vendor, or disable bitcode for this target.", file.path()); + _internal.filesWithBitcode.clear(); + _internal.dropAllBitcode = true; + break; + case ld::kPlatform_iOS: + case ld::kPlatform_iOSSimulator: + throwf("'%s' does not contain bitcode. " + "You must rebuild it with bitcode enabled (Xcode setting ENABLE_BITCODE), obtain an updated library from the vendor, or disable bitcode for this target.", file.path()); + break; + case ld::kPlatform_watchOS: + case ld::kPlatform_watchOSSimulator: + case ld::kPlatform_tvOS: + case ld::kPlatform_tvOSSimulator: + throwf("'%s' does not contain bitcode. " + "You must rebuild it with bitcode enabled (Xcode setting ENABLE_BITCODE) or obtain an updated library from the vendor", file.path()); + break; + } + }); + } + } + // Error on bitcode marker in non-system frameworks if -bitcode_verify is used + if ( _options.verifyBitcode() && !isSystemFramework && + dylibFile->getBitcode() != NULL && dylibFile->getBitcode()->isMarker() ) + throwf("bitcode bundle could not be generated because '%s' was built without full bitcode. " + "All frameworks and dylibs for bitcode must be generated from Xcode Archive or Install build", + dylibFile->path()); + } + + // Don't allow swift frameworks to link other swift frameworks. + if ( !_internal.firstSwiftDylibFile && _options.outputKind() == Options::kDynamicLibrary + && file.swiftVersion() != 0 && getenv("LD_DISALLOW_SWIFT_LINKING_SWIFT")) { + // Check that we aren't a whitelisted path. + bool inWhiteList = false; + const char *whitelistedPaths[] = { "/System/Library/PrivateFrameworks/Swift" }; + for (auto whitelistedPath : whitelistedPaths) { + if (!strncmp(whitelistedPath, dylibFile->installPath(), strlen(whitelistedPath))) { + inWhiteList = true; + break; + } + } + if (!inWhiteList) { + _internal.firstSwiftDylibFile = dylibFile; + } + } + + // verify dylibs 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]; + Options::userReadableSwiftVersion(file.swiftVersion(), fileVersion); + Options::userReadableSwiftVersion(_internal.swiftVersion, otherVersion); + if ( file.swiftVersion() > _internal.swiftVersion ) { + if ( _options.warnOnSwiftABIVersionMismatches() ) { + warning("%s compiled with newer version of Swift language (%s) than previous files (%s)", + file.path(), fileVersion, otherVersion); + } else { + throwf("%s compiled with newer version of Swift language (%s) than previous files (%s)", + file.path(), fileVersion, otherVersion); + } + } + else { + if ( _options.warnOnSwiftABIVersionMismatches() ) { + warning("%s compiled with older 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); + } + } + } } - } + if ( _options.checkDylibsAreAppExtensionSafe() && !dylibFile->appExtensionSafe() ) { + warning("linking against a dylib which is 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.platforms().contains(ld::kPlatform_iOS) && !_options.platforms().minOS(iOS_8_0) ) { + // only warn about linking against embedded dylib if it is built for iOS 8 or later + if ( dylibFile->platforms().minOS(ld::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, @loader_path, etc.", depInstallName, dylibFile->path()); + } else 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()); + } + } + } } 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); @@ -418,14 +691,14 @@ 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", _options.demangleSymbol(name), atom.file()->path()); + warning("target OS does not support re-exporting symbol %s from %s\n", _options.demangleSymbol(name), atom.safeFilePath()); else 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", _options.demangleSymbol(name), atom.file()->path()); + warning("cannot export hidden symbol %s from %s", _options.demangleSymbol(name), atom.safeFilePath()); else warning("cannot export hidden symbol %s", _options.demangleSymbol(name)); } @@ -437,7 +710,7 @@ 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", _options.demangleSymbol(name), atom.file()->path()); + throwf("requested re-export symbol %s is not from a dylib, but from %s\n", _options.demangleSymbol(name), atom.safeFilePath()); } } break; @@ -448,7 +721,7 @@ 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", _options.demangleSymbol(name), atom.file()->path()); + throwf("requested re-export symbol %s is not from a dylib, but from %s\n", _options.demangleSymbol(name), atom.safeFilePath()); } break; } @@ -456,21 +729,28 @@ 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); // tell symbol table about non-static atoms if ( atom.scope() != ld::Atom::scopeTranslationUnit ) { - _symbolTable.add(atom, _options.deadCodeStrip() && _completedInitialObjectFiles); + _symbolTable.add(atom, _options.deadCodeStrip() && (_completedInitialObjectFiles || _options.allowDeadDuplicates())); // add symbol aliases defined on the command line if ( _options.haveCmdLineAliases() ) { 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); - this->doAtom(*alias); + if ( strcmp(it->realName, it->alias) == 0 ) { + warning("ignoring alias of itself '%s'", it->realName); + } + else { + const AliasAtom* alias = new AliasAtom(atom, it->alias); + _aliasesFromCmdLine.push_back(alias); + this->doAtom(*alias); + } } } } @@ -482,11 +762,30 @@ void Resolver::doAtom(const ld::Atom& atom) // remember if any atoms are proxies that require LTO if ( atom.contentType() == ld::Atom::typeLTOtemporary ) _haveLLVMObjs = true; - + + // remember if any atoms are aliases + if ( atom.section().type() == ld::Section::typeTempAlias ) + _haveAliases = true; + + // error or warn about initializers + if ( (atom.section().type() == ld::Section::typeInitializerPointers) && !_havellvmProfiling ) { + switch ( _options.initializersTreatment() ) { + case Options::kError: + throwf("static initializer found in '%s'",atom.safeFilePath()); + case Options::kWarning: + warning("static initializer found in '%s'. Use -no_inits to make this an error. Use -no_warn_inits to suppress warning",atom.safeFilePath()); + break; + default: + break; + } + } + if ( _options.deadCodeStrip() ) { // add to set of dead-strip-roots, all symbols that the compiler marks as don't strip if ( atom.dontDeadStrip() ) _deadStripRoots.insert(&atom); + else if ( atom.dontDeadStripIfReferencesLive() ) + _dontDeadStripIfReferencesLive.push_back(&atom); if ( atom.scope() == ld::Atom::scopeGlobal ) { // -exported_symbols_list that has wildcards and -dead_strip @@ -506,6 +805,8 @@ 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: @@ -523,6 +824,8 @@ 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 ) ) { @@ -634,14 +937,34 @@ 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)); } } @@ -657,6 +980,10 @@ void Resolver::resolveUndefines() } } + // After resolving all the undefs within the linkageUnit, record all the remaining undefs and all the proxies. + if (_options.bundleBitcode() && _options.hideSymbols()) + _symbolTable.mustPreserveForBitcode(_internal.allUndefProxies); + } @@ -665,12 +992,12 @@ void Resolver::markLive(const ld::Atom& atom, WhyLiveBackChain* previous) //fprintf(stderr, "markLive(%p) %s\n", &atom, atom.name()); // if -why_live cares about this symbol, then dump chain if ( (previous->referer != NULL) && _options.printWhyLive(atom.name()) ) { - fprintf(stderr, "%s from %s\n", atom.name(), atom.file()->path()); + fprintf(stderr, "%s from %s\n", atom.name(), atom.safeFilePath()); int depth = 1; for(WhyLiveBackChain* p = previous; p != NULL; p = p->previous, ++depth) { for(int i=depth; i > 0; --i) fprintf(stderr, " "); - fprintf(stderr, "%s from %s\n", p->referer->name(), p->referer->file()->path()); + fprintf(stderr, "%s from %s\n", p->referer->name(), p->referer->safeFilePath()); } } @@ -693,10 +1020,14 @@ 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: case ld::Fixup::kindStoreTargetAddressLittleEndian64: +#if SUPPORT_ARCH_arm64e + case ld::Fixup::kindStoreTargetAddressLittleEndianAuth64: +#endif case ld::Fixup::kindStoreTargetAddressBigEndian32: case ld::Fixup::kindStoreTargetAddressBigEndian64: case ld::Fixup::kindStoreTargetAddressX86PCRel32: @@ -709,6 +1040,14 @@ 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: + case ld::Fixup::kindStoreTargetAddressARM64TLVPLoadPage21: + case ld::Fixup::kindStoreTargetAddressARM64TLVPLoadNowLeaPage21: +#endif if ( fit->binding == ld::Fixup::bindingByContentBound ) { // normally this was done in convertReferencesToIndirect() // but a archive loaded .o file may have a forward reference @@ -840,6 +1179,38 @@ void Resolver::deadStripOptimize(bool force) this->markLive(**it, &rootChain); } + // special case atoms that need to be live if they reference something live + if ( ! _dontDeadStripIfReferencesLive.empty() ) { + for (std::vector::iterator it=_dontDeadStripIfReferencesLive.begin(); it != _dontDeadStripIfReferencesLive.end(); ++it) { + const Atom* liveIfRefLiveAtom = *it; + //fprintf(stderr, "live-if-live atom: %s\n", liveIfRefLiveAtom->name()); + if ( liveIfRefLiveAtom->live() ) + continue; + bool hasLiveRef = false; + for (ld::Fixup::iterator fit=liveIfRefLiveAtom->fixupsBegin(); fit != liveIfRefLiveAtom->fixupsEnd(); ++fit) { + const Atom* target = NULL; + switch ( fit->binding ) { + case ld::Fixup::bindingDirectlyBound: + target = fit->u.target; + break; + case ld::Fixup::bindingsIndirectlyBound: + target = _internal.indirectBindingTable[fit->u.bindingIndex]; + break; + default: + break; + } + if ( (target != NULL) && target->live() ) + hasLiveRef = true; + } + if ( hasLiveRef ) { + WhyLiveBackChain rootChain; + rootChain.previous = NULL; + rootChain.referer = liveIfRefLiveAtom; + this->markLive(*liveIfRefLiveAtom, &rootChain); + } + } + } + // now remove all non-live atoms from _atoms const bool log = false; if ( log ) { @@ -851,10 +1222,13 @@ void Resolver::deadStripOptimize(bool force) } if ( _haveLLVMObjs && !force ) { + std::copy_if(_atoms.begin(), _atoms.end(), std::back_inserter(_internal.deadAtoms), NotLiveLTO() ); // 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 { + std::copy_if(_atoms.begin(), _atoms.end(), std::back_inserter(_internal.deadAtoms), NotLive() ); _atoms.erase(std::remove_if(_atoms.begin(), _atoms.end(), NotLive()), _atoms.end()); } @@ -1021,11 +1395,11 @@ bool Resolver::printReferencedBy(const char* name, SymbolTable::IndirectBindingS ++foundReferenceCount; } else if ( atom->contentType() == ld::Atom::typeCFI ) { - fprintf(stderr, " Dwarf Exception Unwind Info (__eh_frame) in %s\n", pathLeafName(atom->file()->path())); + fprintf(stderr, " Dwarf Exception Unwind Info (__eh_frame) in %s\n", pathLeafName(atom->safeFilePath())); ++foundReferenceCount; } else { - fprintf(stderr, " %s in %s\n", _options.demangleSymbol(atom->name()), pathLeafName(atom->file()->path())); + fprintf(stderr, " %s in %s\n", _options.demangleSymbol(atom->name()), pathLeafName(atom->safeFilePath())); ++foundReferenceCount; break; // if undefined used twice in a function, only show first } @@ -1085,6 +1459,10 @@ void Resolver::checkUndefines(bool force) int unresolvableExportsCount = 0; if ( unresolvableCount != 0 ) { if ( doPrint ) { + for (const auto& lib : _internal.missingLinkerOptionLibraries) + warning("Could not find auto-linked library '%s'", lib); + for (const auto& frm : _internal.missingLinkerOptionFrameworks) + warning("Could not find auto-linked framework '%s'", frm); if ( _options.printArchPrefix() ) fprintf(stderr, "Undefined symbols for architecture %s:\n", _options.architectureName()); else @@ -1109,6 +1487,10 @@ 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) { @@ -1237,6 +1619,7 @@ void Resolver::fillInHelpersInInternalState() } _internal.classicBindingHelper = NULL; + // FIXME: What about fMakeThreadedStartsSection? if ( needsStubHelper && !_options.makeCompressedDyldInfo() ) { // "dyld_stub_binding_helper" comes from .o file, so should already exist in symbol table if ( _symbolTable.hasName("dyld_stub_binding_helper") ) { @@ -1257,6 +1640,7 @@ void Resolver::fillInHelpersInInternalState() } _internal.compressedFastBinderProxy = NULL; + // FIXME: What about fMakeThreadedStartsSection? if ( needsStubHelper && _options.makeCompressedDyldInfo() ) { // "dyld_stub_binder" comes from libSystem.dylib so will need to manually resolve if ( !_symbolTable.hasName("dyld_stub_binder") ) { @@ -1286,7 +1670,12 @@ 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)); + + // Don't allow swift frameworks to link other swift frameworks. + if ( _internal.someObjectFileHasSwift && _internal.firstSwiftDylibFile != nullptr ) + throwf("linking swift frameworks against other swift frameworks (%s) is not permitted", + _internal.firstSwiftDylibFile->path()); } void Resolver::fillInEntryPoint() @@ -1294,7 +1683,38 @@ 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() { @@ -1317,39 +1737,74 @@ void Resolver::linkTimeOptimize() 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.ltoCachePath = _options.ltoCachePath(); + optOpt.ltoPruneIntervalOverwrite = _options.ltoPruneIntervalOverwrite(); + optOpt.ltoPruneInterval = _options.ltoPruneInterval(); + optOpt.ltoPruneAfter = _options.ltoPruneAfter(); + optOpt.ltoMaxCacheSize = _options.ltoMaxCacheSize(); optOpt.preserveAllGlobals = _options.allGlobalsAreDeadStripRoots() || _options.hasExportRestrictList(); optOpt.verbose = _options.verbose(); optOpt.saveTemps = _options.saveTempFiles(); + optOpt.ltoCodegenOnly = _options.ltoCodegenOnly(); optOpt.pie = _options.positionIndependentExecutable(); optOpt.mainExecutable = _options.linkingMainExecutable();; optOpt.staticExecutable = (_options.outputKind() == Options::kStaticExecutable); + optOpt.preload = (_options.outputKind() == Options::kPreload); 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.armUsesZeroCostExceptions = _options.armUsesZeroCostExceptions(); + optOpt.simulator = _options.targetIOSSimulator(); + optOpt.ignoreMismatchPlatform = ((_options.outputKind() == Options::kPreload) || (_options.outputKind() == Options::kStaticExecutable)); +#if SUPPORT_ARCH_arm64e + optOpt.supportsAuthenticatedPointers = _options.supportsAuthenticatedPointers(); +#endif + optOpt.bitcodeBundle = (_options.bundleBitcode() && (_options.bitcodeKind() != Options::kBitcodeMarker)); + optOpt.maxDefaultCommonAlignment = _options.maxDefaultCommonAlign(); optOpt.arch = _options.architecture(); + optOpt.mcpu = _options.mcpuLTO(); + optOpt.platforms = _options.platforms(); optOpt.llvmOptions = &_options.llvmOptions(); + optOpt.initialUndefines = &_options.initialUndefines(); std::vector newAtoms; std::vector 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(); - // run through all atoms again and make sure newly codegened atoms have refernces bound + // 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) for(std::vector::iterator uit = additionalUndefines.begin(); uit != additionalUndefines.end(); ++uit) { const char *targetName = *uit; @@ -1361,13 +1816,32 @@ void Resolver::linkTimeOptimize() // if -dead_strip on command line if ( _options.deadCodeStrip() ) { - // clear liveness bit + // run through all atoms again and make live_section LTO atoms are preserved from dead_stripping if needed + _dontDeadStripIfReferencesLive.clear(); for (std::vector::const_iterator it=_atoms.begin(); it != _atoms.end(); ++it) { + const ld::Atom* atom = *it; + if ( atom->dontDeadStripIfReferencesLive() ) { + _dontDeadStripIfReferencesLive.push_back(atom); + } + + // clear liveness bit (const_cast(*it))->setLive((*it)->dontDeadStrip()); } // and re-compute dead code 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) @@ -1375,10 +1849,28 @@ void Resolver::linkTimeOptimize() } else { // last chance to check for undefines + this->resolveUndefines(); this->checkUndefines(true); // check new code does not override some dylib this->checkDylibSymbolCollisions(); + + // remove undefs from LTO objects that gets optimized away + std::unordered_set mustPreserve; + if ( _internal.classicBindingHelper != NULL ) + mustPreserve.insert(_internal.classicBindingHelper); + if ( _internal.compressedFastBinderProxy != NULL ) + mustPreserve.insert(_internal.compressedFastBinderProxy); + if ( _internal.lazyBindingHelper != NULL ) + mustPreserve.insert(_internal.lazyBindingHelper); + if ( const ld::Atom* entry = this->entryPoint(true) ) + mustPreserve.insert(entry); + for (Options::UndefinesIterator uit=_options.initialUndefinesBegin(); uit != _options.initialUndefinesEnd(); ++uit) { + SymbolTable::IndirectBindingSlot slot = _symbolTable.findSlotForName(*uit); + if ( _internal.indirectBindingTable[slot] != NULL ) + mustPreserve.insert(_internal.indirectBindingTable[slot]); + } + _symbolTable.removeDeadUndefs(_atoms, mustPreserve); } } @@ -1415,6 +1907,20 @@ void Resolver::tweakWeakness() } } +void Resolver::buildArchivesList() +{ + // Determine which archives were linked and update the internal state. + _inputFiles.archives(_internal); +} + +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() { @@ -1426,12 +1932,14 @@ void Resolver::resolve() this->deadStripOptimize(); this->checkUndefines(); this->checkDylibSymbolCollisions(); + this->syncAliases(); this->removeCoalescedAwayAtoms(); this->fillInEntryPoint(); this->linkTimeOptimize(); this->fillInInternalState(); this->tweakWeakness(); _symbolTable.checkDuplicateSymbols(); + this->buildArchivesList(); }