/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*- * * Copyright (c) 2006-2010 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@ */ #ifndef __LTO_READER_H__ #define __LTO_READER_H__ #include #include #include #include #include #include #include #include #include #include "MachOFileAbstraction.hpp" #include "Architectures.hpp" #include "ld.hpp" #include "macho_relocatable_file.h" #include "lto_file.h" #include "llvm-c/lto.h" namespace lto { // // ld64 only tracks non-internal symbols from an llvm bitcode file. // We model this by having an InternalAtom which represent all internal functions and data. // All non-interal symbols from a bitcode file are represented by an Atom // and each Atom has a reference to the InternalAtom. The InternalAtom // also has references to each symbol external to the bitcode file. // class InternalAtom : public ld::Atom { public: InternalAtom(class File& f); // overrides of ld::Atom virtual ld::File* file() const { return &_file; } virtual bool translationUnitSource(const char** dir, const char** nm) const { return false; } virtual const char* name() const { return "import-atom"; } virtual uint64_t size() const { return 0; } virtual uint64_t objectAddress() const { return 0; } virtual void copyRawContent(uint8_t buffer[]) const { } virtual void setScope(Scope) { } virtual ld::Fixup::iterator fixupsBegin() const { return &_undefs[0]; } virtual ld::Fixup::iterator fixupsEnd() const { return &_undefs[_undefs.size()]; } // for adding references to symbols outside bitcode file void addReference(const char* nm) { _undefs.push_back(ld::Fixup(0, ld::Fixup::k1of1, ld::Fixup::kindNone, false, nm)); } private: ld::File& _file; mutable std::vector _undefs; }; // // LLVM bitcode file // class File : public ld::relocatable::File { public: File(const char* path, time_t mTime, const uint8_t* content, uint32_t contentLength, uint32_t ordinal, cpu_type_t arch); virtual ~File(); // overrides of ld::File virtual bool forEachAtom(ld::File::AtomHandler&) const; virtual bool justInTimeforEachAtom(const char* name, ld::File::AtomHandler&) const { return false; } virtual uint32_t cpuSubType() const { return _cpuSubType; } // overrides of ld::relocatable::File virtual bool objcReplacementClasses() const { return false; } virtual DebugInfoKind debugInfo() const { return _debugInfo; } virtual const char* debugInfoPath() const { return _debugInfoPath; } virtual time_t debugInfoModificationTime() const { return _debugInfoModTime; } virtual const std::vector* stabs() const { return NULL; } virtual bool canScatterAtoms() const { return true; } lto_module_t module() { return _module; } class InternalAtom& internalAtom() { return _internalAtom; } void setDebugInfo(ld::relocatable::File::DebugInfoKind k, const char* pth, time_t modTime, uint32_t subtype) { _debugInfo = k; _debugInfoPath = pth; _debugInfoModTime = modTime; _cpuSubType = subtype;} private: friend class Atom; friend class InternalAtom; friend class Parser; cpu_type_t _architecture; class InternalAtom _internalAtom; class Atom* _atomArray; uint32_t _atomArrayCount; lto_module_t _module; const char* _debugInfoPath; time_t _debugInfoModTime; ld::Section _section; ld::Fixup _fixupToInternal; ld::relocatable::File::DebugInfoKind _debugInfo; uint32_t _cpuSubType; }; // // Atom acts as a proxy Atom for the symbols that are exported by LLVM bitcode file. Initially, // Reader creates Atoms to allow linker proceed with usual symbol resolution phase. After // optimization is performed, real Atoms are created for these symobls. However these real Atoms // are not inserted into global symbol table. Atom holds real Atom and forwards appropriate // methods to real atom. // class Atom : public ld::Atom { public: Atom(File& f, const char* name, ld::Atom::Scope s, ld::Atom::Definition d, ld::Atom::Combine c, ld::Atom::Alignment a); // overrides of ld::Atom virtual ld::File* file() const { return &_file; } virtual bool translationUnitSource(const char** dir, const char** nm) const { return (_compiledAtom ? _compiledAtom->translationUnitSource(dir, nm) : false); } virtual const char* name() const { return _name; } virtual uint64_t size() const { return (_compiledAtom ? _compiledAtom->size() : 0); } virtual uint64_t objectAddress() const { return (_compiledAtom ? _compiledAtom->objectAddress() : 0); } virtual void copyRawContent(uint8_t buffer[]) const { if (_compiledAtom) _compiledAtom->copyRawContent(buffer); } virtual const uint8_t* rawContentPointer() const { return (_compiledAtom ? _compiledAtom->rawContentPointer() : NULL); } virtual unsigned long contentHash(const class ld::IndirectBindingTable& ibt) const { return (_compiledAtom ? _compiledAtom->contentHash(ibt) : 0); } virtual bool canCoalesceWith(const ld::Atom& rhs, const class ld::IndirectBindingTable& ibt) const { return (_compiledAtom ? _compiledAtom->canCoalesceWith(rhs,ibt) : false); } virtual ld::Fixup::iterator fixupsBegin() const { return (_compiledAtom ? _compiledAtom->fixupsBegin() : (ld::Fixup*)&_file._fixupToInternal); } virtual ld::Fixup::iterator fixupsEnd() const { return (_compiledAtom ? _compiledAtom->fixupsEnd() : &((ld::Fixup*)&_file._fixupToInternal)[1]); } virtual ld::Atom::UnwindInfo::iterator beginUnwind() const { return (_compiledAtom ? _compiledAtom->beginUnwind() : NULL); } virtual ld::Atom::UnwindInfo::iterator endUnwind() const { return (_compiledAtom ? _compiledAtom->endUnwind() : NULL); } virtual ld::Atom::LineInfo::iterator beginLineInfo() const { return (_compiledAtom ? _compiledAtom->beginLineInfo() : NULL); } virtual ld::Atom::LineInfo::iterator endLineInfo() const { return (_compiledAtom ? _compiledAtom->endLineInfo() : NULL); } const ld::Atom* compiledAtom() { return _compiledAtom; } void setCompiledAtom(const ld::Atom& atom); private: File& _file; const char* _name; const ld::Atom* _compiledAtom; }; class Parser { public: static bool validFile(const uint8_t* fileContent, uint64_t fileLength, cpu_type_t architecture, cpu_subtype_t subarch); static const char* fileKind(const uint8_t* fileContent, uint64_t fileLength); static File* parse(const uint8_t* fileContent, uint64_t fileLength, const char* path, time_t modTime, uint32_t ordinal, cpu_type_t architecture, cpu_subtype_t subarch, bool logAllFiles); static bool libLTOisLoaded() { return (::lto_get_version() != NULL); } static bool optimize( const std::vector& allAtoms, ld::Internal& state, uint32_t nextInputOrdinal, const OptimizeOptions& options, ld::File::AtomHandler& handler, std::vector& newAtoms, std::vector& additionalUndefines); static const char* ltoVersion() { return ::lto_get_version(); } private: static const char* tripletPrefixForArch(cpu_type_t arch); static ld::relocatable::File* parseMachOFile(const uint8_t* p, size_t len, uint32_t nextInputOrdinal, const OptimizeOptions& options); class CStringEquals { public: bool operator()(const char* left, const char* right) const { return (strcmp(left, right) == 0); } }; typedef __gnu_cxx::hash_set, CStringEquals> CStringSet; typedef __gnu_cxx::hash_map, CStringEquals> CStringToAtom; class AtomSyncer : public ld::File::AtomHandler { public: AtomSyncer(std::vector& a, std::vector&na, CStringToAtom la, CStringToAtom dla, const OptimizeOptions& options) : _options(options), _additionalUndefines(a), _newAtoms(na), _llvmAtoms(la), _deadllvmAtoms(dla) { } virtual void doAtom(const class ld::Atom&); virtual void doFile(const class ld::File&) { } const OptimizeOptions& _options; std::vector& _additionalUndefines; std::vector& _newAtoms; CStringToAtom _llvmAtoms; CStringToAtom _deadllvmAtoms; }; static std::vector _s_files; }; std::vector Parser::_s_files; bool Parser::validFile(const uint8_t* fileContent, uint64_t fileLength, cpu_type_t architecture, cpu_subtype_t subarch) { switch (architecture) { case CPU_TYPE_I386: return ::lto_module_is_object_file_in_memory_for_target(fileContent, fileLength, "i386-"); case CPU_TYPE_X86_64: return ::lto_module_is_object_file_in_memory_for_target(fileContent, fileLength, "x86_64-"); case CPU_TYPE_ARM: switch ( subarch ) { case CPU_SUBTYPE_ARM_V6: return ::lto_module_is_object_file_in_memory_for_target(fileContent, fileLength, "armv6-"); case CPU_SUBTYPE_ARM_V7: return ::lto_module_is_object_file_in_memory_for_target(fileContent, fileLength, "thumbv7-"); } break; case CPU_TYPE_POWERPC: return ::lto_module_is_object_file_in_memory_for_target(fileContent, fileLength, "powerpc-"); } return false; } const char* Parser::fileKind(const uint8_t* p, uint64_t fileLength) { if ( (p[0] == 0xDE) && (p[1] == 0xC0) && (p[2] == 0x17) && (p[3] == 0x0B) ) { uint32_t arch = LittleEndian::get32(*((uint32_t*)(&p[16]))); switch (arch) { case CPU_TYPE_POWERPC: return "ppc"; case CPU_TYPE_I386: return "i386"; case CPU_TYPE_X86_64: return "x86_64"; case CPU_TYPE_ARM: if ( ::lto_module_is_object_file_in_memory_for_target(p, fileLength, "armv6-") ) return "armv6"; if ( ::lto_module_is_object_file_in_memory_for_target(p, fileLength, "thumbv7-") ) return "armv7"; return "arm"; } return "unknown bitcode architecture"; } return NULL; } File* Parser::parse(const uint8_t* fileContent, uint64_t fileLength, const char* path, time_t modTime, uint32_t ordinal, cpu_type_t architecture, cpu_subtype_t subarch, bool logAllFiles) { File* f = new File(path, modTime, fileContent, fileLength, ordinal, architecture); _s_files.push_back(f); if ( logAllFiles ) printf("%s\n", path); return f; } ld::relocatable::File* Parser::parseMachOFile(const uint8_t* p, size_t len, uint32_t nextInputOrdinal, const OptimizeOptions& options) { mach_o::relocatable::ParserOptions objOpts; objOpts.architecture = options.arch; objOpts.objSubtypeMustMatch = false; objOpts.logAllFiles = false; objOpts.convertUnwindInfo = true; objOpts.subType = 0; // mach-o parsing is done in-memory, but need path for debug notes const char* path = "/tmp/lto.o"; time_t modTime = 0; if ( options.tmpObjectFilePath != NULL ) { path = options.tmpObjectFilePath; struct stat statBuffer; if ( stat(options.tmpObjectFilePath, &statBuffer) == 0 ) modTime = statBuffer.st_mtime; } ld::relocatable::File* result = mach_o::relocatable::parse(p, len, path, modTime, nextInputOrdinal, objOpts); if ( result != NULL ) return result; throw "LLVM LTO, file is not of required architecture"; } File::File(const char* pth, time_t mTime, const uint8_t* content, uint32_t contentLength, uint32_t ord, cpu_type_t arch) : ld::relocatable::File(pth,mTime,ord), _architecture(arch), _internalAtom(*this), _atomArray(NULL), _atomArrayCount(0), _module(NULL), _debugInfoPath(pth), _section("__TEXT_", "__tmp_lto", ld::Section::typeTempLTO), _fixupToInternal(0, ld::Fixup::k1of1, ld::Fixup::kindNone, &_internalAtom), _debugInfo(ld::relocatable::File::kDebugInfoNone), _cpuSubType(0) { const bool log = false; // create llvm module _module = ::lto_module_create_from_memory(content, contentLength); if ( _module == NULL ) throwf("could not parse object file %s: %s", pth, lto_get_error_message()); if ( log ) fprintf(stderr, "bitcode file: %s\n", pth); // create atom for each global symbol in module uint32_t count = ::lto_module_get_num_symbols(_module); _atomArray = (Atom*)malloc(sizeof(Atom)*count); for (uint32_t i=0; i < count; ++i) { const char* name = ::lto_module_get_symbol_name(_module, i); lto_symbol_attributes attr = lto_module_get_symbol_attribute(_module, i); // LTO doesn't like dtrace symbols // ignore dtrace static probes for now // later when codegen is done and a mach-o file is produces the probes will be processed if ( (strncmp(name, "___dtrace_probe$", 16) == 0) || (strncmp(name, "___dtrace_isenabled$", 20) == 0) ) continue; ld::Atom::Definition def; ld::Atom::Combine combine = ld::Atom::combineNever; switch ( attr & LTO_SYMBOL_DEFINITION_MASK ) { case LTO_SYMBOL_DEFINITION_REGULAR: def = ld::Atom::definitionRegular; break; case LTO_SYMBOL_DEFINITION_TENTATIVE: def = ld::Atom::definitionTentative; break; case LTO_SYMBOL_DEFINITION_WEAK: def = ld::Atom::definitionRegular; combine = ld::Atom::combineByName; break; case LTO_SYMBOL_DEFINITION_UNDEFINED: case LTO_SYMBOL_DEFINITION_WEAKUNDEF: def = ld::Atom::definitionProxy; break; default: throwf("unknown definition kind for symbol %s in bitcode file %s", name, pth); } // make LLVM atoms for definitions and a reference for undefines if ( def != ld::Atom::definitionProxy ) { ld::Atom::Scope scope; switch ( attr & LTO_SYMBOL_SCOPE_MASK) { case LTO_SYMBOL_SCOPE_INTERNAL: scope = ld::Atom::scopeTranslationUnit; break; case LTO_SYMBOL_SCOPE_HIDDEN: scope = ld::Atom::scopeLinkageUnit; break; case LTO_SYMBOL_SCOPE_DEFAULT: scope = ld::Atom::scopeGlobal; break; default: throwf("unknown scope for symbol %s in bitcode file %s", name, pth); } // only make atoms for non-internal symbols if ( scope == ld::Atom::scopeTranslationUnit ) continue; uint8_t alignment = (attr & LTO_SYMBOL_ALIGNMENT_MASK); // make Atom using placement new operator new (&_atomArray[_atomArrayCount++]) Atom(*this, name, scope, def, combine, alignment); if ( scope == ld::Atom::scopeLinkageUnit ) _internalAtom.addReference(name); if ( log ) fprintf(stderr, "\t0x%08X %s\n", attr, name); } else { // add to list of external references _internalAtom.addReference(name); if ( log ) fprintf(stderr, "\t%s (undefined)\n", name); } } } File::~File() { if ( _module != NULL ) ::lto_module_dispose(_module); } bool File::forEachAtom(ld::File::AtomHandler& handler) const { handler.doAtom(_internalAtom); for(uint32_t i=0; i < _atomArrayCount; ++i) { handler.doAtom(_atomArray[i]); } return true; } InternalAtom::InternalAtom(File& f) : ld::Atom(f._section, ld::Atom::definitionRegular, ld::Atom::combineNever, ld::Atom::scopeTranslationUnit, ld::Atom::typeLTOtemporary, ld::Atom::symbolTableNotIn, true, false, false, ld::Atom::Alignment(0)), _file(f) { } Atom::Atom(File& f, const char* nm, ld::Atom::Scope s, ld::Atom::Definition d, ld::Atom::Combine c, ld::Atom::Alignment a) : ld::Atom(f._section, d, c, s, ld::Atom::typeLTOtemporary, ld::Atom::symbolTableIn, false, false, false, a), _file(f), _name(nm), _compiledAtom(NULL) { } void Atom::setCompiledAtom(const ld::Atom& atom) { // set delegate so virtual methods go to it _compiledAtom = &atom; //fprintf(stderr, "setting lto atom %p to delegate to mach-o atom %p (%s)\n", this, &atom, atom.name()); // update fields in ld::Atom to match newly constructed mach-o atom (const_cast(this))->setAttributesFromAtom(atom); } bool Parser::optimize( const std::vector& allAtoms, ld::Internal& state, uint32_t nextInputOrdinal, const OptimizeOptions& options, ld::File::AtomHandler& handler, std::vector& newAtoms, std::vector& additionalUndefines) { const bool logMustPreserve = false; const bool logExtraOptions = false; const bool logBitcodeFiles = false; const bool logAtomsBeforeSync = false; // exit quickly if nothing to do if ( _s_files.size() == 0 ) return false; // print out LTO version string if -v was used if ( options.verbose ) fprintf(stderr, "%s\n", lto_get_version()); // create optimizer and add each Reader lto_code_gen_t generator = ::lto_codegen_create(); for (std::vector::iterator it=_s_files.begin(); it != _s_files.end(); ++it) { if ( logBitcodeFiles ) fprintf(stderr, "lto_codegen_add_module(%s)\n", (*it)->path()); if ( ::lto_codegen_add_module(generator, (*it)->module()) ) throwf("lto: could not merge in %s because %s", (*it)->path(), ::lto_get_error_message()); } // add any -mllvm command line options for (std::vector::const_iterator it=options.llvmOptions->begin(); it != options.llvmOptions->end(); ++it) { if ( logExtraOptions ) fprintf(stderr, "passing option to llvm: %s\n", *it); ::lto_codegen_debug_options(generator, *it); } // The atom graph uses directed edges (references). Collect all references where // originating atom is not part of any LTO Reader. This allows optimizer to optimize an // external (i.e. not originated from same .o file) reference if all originating atoms are also // defined in llvm bitcode file. CStringSet nonLLVMRefs; CStringToAtom llvmAtoms; bool hasNonllvmAtoms = false; for (std::vector::const_iterator it = allAtoms.begin(); it != allAtoms.end(); ++it) { const ld::Atom* atom = *it; // only look at references that come from an atom that is not an llvm atom if ( atom->contentType() != ld::Atom::typeLTOtemporary ) { if ( (atom->section().type() != ld::Section::typeMachHeader) && (atom->definition() != ld::Atom::definitionProxy) ) { hasNonllvmAtoms = true; } const ld::Atom* target; for (ld::Fixup::iterator fit=atom->fixupsBegin(); fit != atom->fixupsEnd(); ++fit) { switch ( fit->binding ) { case ld::Fixup::bindingDirectlyBound: // that reference an llvm atom if ( fit->u.target->contentType() == ld::Atom::typeLTOtemporary ) nonLLVMRefs.insert(fit->u.target->name()); break; case ld::Fixup::bindingsIndirectlyBound: target = state.indirectBindingTable[fit->u.bindingIndex]; if ( target == NULL ) throwf("'%s' in %s contains undefined reference", atom->name(), atom->file()->path()); assert(target != NULL); if ( target->contentType() == ld::Atom::typeLTOtemporary ) nonLLVMRefs.insert(target->name()); default: break; } } } else { llvmAtoms[atom->name()] = (Atom*)atom; } } // if entry point is in a llvm bitcode file, it must be preserved by LTO if ( state.entryPoint!= NULL ) { if ( state.entryPoint->contentType() == ld::Atom::typeLTOtemporary ) nonLLVMRefs.insert(state.entryPoint->name()); } // deadAtoms are the atoms that the linker coalesced. For instance weak or tentative definitions // overriden by another atom. If any of these deadAtoms are llvm atoms and they were replaced // with a mach-o atom, we need to tell the lto engine to preserve (not optimize away) its dead // atom so that the linker can replace it with the mach-o one later. CStringToAtom deadllvmAtoms; for (std::vector::const_iterator it = allAtoms.begin(); it != allAtoms.end(); ++it) { const ld::Atom* atom = *it; if ( atom->coalescedAway() && (atom->contentType() == ld::Atom::typeLTOtemporary) ) { const char* name = atom->name(); if ( logMustPreserve ) fprintf(stderr, "lto_codegen_add_must_preserve_symbol(%s) because linker coalesce away and replace with a mach-o atom\n", name); ::lto_codegen_add_must_preserve_symbol(generator, name); deadllvmAtoms[name] = (Atom*)atom; } } for (std::vector::iterator it=_s_files.begin(); it != _s_files.end(); ++it) { File* file = *it; for(uint32_t i=0; i < file->_atomArrayCount; ++i) { Atom* llvmAtom = &file->_atomArray[i]; if ( llvmAtom->coalescedAway() ) { const char* name = llvmAtom->name(); if ( deadllvmAtoms.find(name) == deadllvmAtoms.end() ) { if ( logMustPreserve ) fprintf(stderr, "lto_codegen_add_must_preserve_symbol(%s) because linker coalesce away and replace with a mach-o atom\n", name); ::lto_codegen_add_must_preserve_symbol(generator, name); deadllvmAtoms[name] = (Atom*)llvmAtom; } } else if ( options.linkerDeadStripping && !llvmAtom->live() ) { const char* name = llvmAtom->name(); deadllvmAtoms[name] = (Atom*)llvmAtom; } } } // tell code generator about symbols that must be preserved for (CStringToAtom::iterator it = llvmAtoms.begin(); it != llvmAtoms.end(); ++it) { const char* name = it->first; Atom* atom = it->second; // Include llvm Symbol in export list if it meets one of following two conditions // 1 - atom scope is global (and not linkage unit). // 2 - included in nonLLVMRefs set. // If a symbol is not listed in exportList then LTO is free to optimize it away. if ( (atom->scope() == ld::Atom::scopeGlobal) ) { if ( logMustPreserve ) fprintf(stderr, "lto_codegen_add_must_preserve_symbol(%s) because global symbol\n", name); ::lto_codegen_add_must_preserve_symbol(generator, name); } else if ( nonLLVMRefs.find(name) != nonLLVMRefs.end() ) { if ( logMustPreserve ) fprintf(stderr, "lto_codegen_add_must_preserve_symbol(%s) because referenced by a mach-o atom\n", name); ::lto_codegen_add_must_preserve_symbol(generator, name); } } // special case running ld -r on all bitcode files to produce another bitcode file (instead of mach-o) if ( options.relocatable && !hasNonllvmAtoms ) { if ( ! ::lto_codegen_write_merged_modules(generator, options.outputFilePath) ) { // HACK, no good way to tell linker we are all done, so just quit exit(0); } warning("could not produce merged bitcode file"); } // set code-gen model lto_codegen_model model = LTO_CODEGEN_PIC_MODEL_DYNAMIC; if ( options.mainExecutable ) { if ( options.staticExecutable ) { // darwin x86_64 "static" code model is really dynamic code model if ( options.arch == CPU_TYPE_X86_64 ) model = LTO_CODEGEN_PIC_MODEL_DYNAMIC; else model = LTO_CODEGEN_PIC_MODEL_STATIC; } else { if ( options.pie ) model = LTO_CODEGEN_PIC_MODEL_DYNAMIC; else model = LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC; } } else { if ( options.allowTextRelocs ) model = LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC; else model = LTO_CODEGEN_PIC_MODEL_DYNAMIC; } if ( ::lto_codegen_set_pic_model(generator, model) ) throwf("could not create set codegen model: %s", lto_get_error_message()); // if requested, save off merged bitcode file if ( options.saveTemps ) { char tempBitcodePath[MAXPATHLEN]; strcpy(tempBitcodePath, options.outputFilePath); strcat(tempBitcodePath, ".lto.bc"); ::lto_codegen_write_merged_modules(generator, tempBitcodePath); } #if LTO_API_VERSION >= 3 // find assembler next to linker char path[PATH_MAX]; uint32_t bufSize = PATH_MAX; if ( _NSGetExecutablePath(path, &bufSize) != -1 ) { char* lastSlash = strrchr(path, '/'); if ( lastSlash != NULL ) { strcpy(lastSlash+1, "as"); struct stat statInfo; if ( stat(path, &statInfo) == 0 ) ::lto_codegen_set_assembler_path(generator, path); } } #endif // run code generator size_t machOFileLen; const uint8_t* machOFile = (uint8_t*)::lto_codegen_compile(generator, &machOFileLen); if ( machOFile == NULL ) throwf("could not do LTO codegen: %s", ::lto_get_error_message()); // if requested, save off temp mach-o file if ( options.saveTemps ) { char tempMachoPath[MAXPATHLEN]; strcpy(tempMachoPath, options.outputFilePath); strcat(tempMachoPath, ".lto.o"); int fd = ::open(tempMachoPath, O_CREAT | O_WRONLY | O_TRUNC, 0666); if ( fd != -1) { ::write(fd, machOFile, machOFileLen); ::close(fd); } // save off merged bitcode file char tempOptBitcodePath[MAXPATHLEN]; strcpy(tempOptBitcodePath, options.outputFilePath); strcat(tempOptBitcodePath, ".lto.opt.bc"); ::lto_codegen_write_merged_modules(generator, tempOptBitcodePath); } // if needed, save temp mach-o file to specific location if ( options.tmpObjectFilePath != NULL ) { int fd = ::open(options.tmpObjectFilePath, O_CREAT | O_WRONLY | O_TRUNC, 0666); if ( fd != -1) { ::write(fd, machOFile, machOFileLen); ::close(fd); } else { warning("could not write LTO temp file '%s', errno=%d", options.tmpObjectFilePath, errno); } } // parse generated mach-o file into a MachOReader ld::relocatable::File* machoFile = parseMachOFile(machOFile, machOFileLen, nextInputOrdinal, options); // sync generated mach-o atoms with existing atoms ld knows about if ( logAtomsBeforeSync ) { fprintf(stderr, "llvmAtoms:\n"); for (CStringToAtom::iterator it = llvmAtoms.begin(); it != llvmAtoms.end(); ++it) { const char* name = it->first; //Atom* atom = it->second; fprintf(stderr, "\t%s\n", name); } fprintf(stderr, "deadllvmAtoms:\n"); for (CStringToAtom::iterator it = deadllvmAtoms.begin(); it != deadllvmAtoms.end(); ++it) { const char* name = it->first; //Atom* atom = it->second; fprintf(stderr, "\t%s\n", name); } } AtomSyncer syncer(additionalUndefines, newAtoms, llvmAtoms, deadllvmAtoms, options); machoFile->forEachAtom(syncer); // Remove InternalAtoms from ld for (std::vector::iterator it=_s_files.begin(); it != _s_files.end(); ++it) { (*it)->internalAtom().setCoalescedAway(); } // Remove Atoms from ld if code generator optimized them away for (CStringToAtom::iterator li = llvmAtoms.begin(), le = llvmAtoms.end(); li != le; ++li) { // check if setRealAtom() called on this Atom if ( li->second->compiledAtom() == NULL ) { //fprintf(stderr, "llvm optimized away %p %s\n", li->second, li->second->name()); li->second->setCoalescedAway(); } } // notify about file level attributes handler.doFile(*machoFile); // if final mach-o file has debug info, update original bitcode files to match for (std::vector::iterator it=_s_files.begin(); it != _s_files.end(); ++it) { (*it)->setDebugInfo(machoFile->debugInfo(), machoFile->path(), machoFile->modificationTime(), machoFile->cpuSubType()); } return true; } void Parser::AtomSyncer::doAtom(const ld::Atom& machoAtom) { // update proxy atoms to point to real atoms and find new atoms const char* name = machoAtom.name(); if ( machoAtom.scope() >= ld::Atom::scopeLinkageUnit ) { CStringToAtom::iterator pos = _llvmAtoms.find(name); if ( pos != _llvmAtoms.end() ) { // turn Atom into a proxy for this mach-o atom pos->second->setCompiledAtom(machoAtom); } else { // an atom of this name was not in the allAtoms list the linker gave us if ( _deadllvmAtoms.find(name) != _deadllvmAtoms.end() ) { // this corresponding to an atom that the linker coalesced away or marked not-live if ( _options.linkerDeadStripping ) { // llvm seems to want this atom and -dead_strip is enabled, so it will be deleted if not needed, so add back Atom* llvmAtom = _deadllvmAtoms[name]; llvmAtom->setCompiledAtom(machoAtom); _newAtoms.push_back(&machoAtom); } else { // Don't pass it back as a new atom } } else { // this is something new that lto conjured up, tell ld its new _newAtoms.push_back(&machoAtom); } } } else { // ld only knew about non-static atoms, so this one must be new _newAtoms.push_back(&machoAtom); } // adjust fixups to go through proxy atoms //fprintf(stderr, "adjusting fixups in atom: %s\n", machoAtom.name()); for (ld::Fixup::iterator fit=machoAtom.fixupsBegin(); fit != machoAtom.fixupsEnd(); ++fit) { switch ( fit->binding ) { case ld::Fixup::bindingNone: break; case ld::Fixup::bindingByNameUnbound: // don't know if this target has been seen by linker before or if it is new // be conservative and tell linker it is new _additionalUndefines.push_back(fit->u.name); //fprintf(stderr, " by name ref to: %s\n", fit->u.name); break; case ld::Fixup::bindingDirectlyBound: // If mach-o atom is referencing another mach-o atom then // reference is not going through Atom proxy. Fix it here to ensure that all // llvm symbol references always go through Atom proxy. if ( fit->u.target->scope() != ld::Atom::scopeTranslationUnit ) { const char* targetName = fit->u.target->name(); CStringToAtom::iterator pos = _llvmAtoms.find(targetName); if ( pos != _llvmAtoms.end() ) { fit->u.target = pos->second; } else { if ( _deadllvmAtoms.find(targetName) != _deadllvmAtoms.end() ) { // target was coalesed away and replace by mach-o atom from a non llvm .o file fit->binding = ld::Fixup::bindingByNameUnbound; fit->u.name = targetName; } } } //fprintf(stderr, " direct ref to: %s (scope=%d)\n", fit->u.target->name(), fit->u.target->scope()); break; case ld::Fixup::bindingByContentBound: //fprintf(stderr, " direct by content to: %s\n", fit->u.target->name()); break; case ld::Fixup::bindingsIndirectlyBound: assert(0 && "indirect binding found in initial mach-o file?"); //fprintf(stderr, " indirect by content to: %u\n", fit->u.bindingIndex); break; } } } // // Used by archive reader to see if member is an llvm bitcode file // bool isObjectFile(const uint8_t* fileContent, uint64_t fileLength, cpu_type_t architecture, cpu_subtype_t subarch) { return Parser::validFile(fileContent, fileLength, architecture, subarch); } // // main function used by linker to instantiate ld::Files // ld::relocatable::File* parse(const uint8_t* fileContent, uint64_t fileLength, const char* path, time_t modTime, uint32_t ordinal, cpu_type_t architecture, cpu_subtype_t subarch, bool logAllFiles) { if ( Parser::validFile(fileContent, fileLength, architecture, subarch) ) return Parser::parse(fileContent, fileLength, path, modTime, ordinal, architecture, subarch, logAllFiles); else return NULL; } // // used by "ld -v" to report version of libLTO.dylib being used // const char* version() { return ::lto_get_version(); } // // used by ld for error reporting // bool libLTOisLoaded() { return (::lto_get_version() != NULL); } // // used by ld for error reporting // const char* archName(const uint8_t* fileContent, uint64_t fileLength) { return Parser::fileKind(fileContent, fileLength); } // // used by ld for doing link time optimization // bool optimize( const std::vector& allAtoms, ld::Internal& state, uint32_t nextInputOrdinal, const OptimizeOptions& options, ld::File::AtomHandler& handler, std::vector& newAtoms, std::vector& additionalUndefines) { return Parser::optimize(allAtoms, state, nextInputOrdinal, options, handler, newAtoms, additionalUndefines); } }; // namespace lto #endif