| //===-- gold-plugin.cpp - Plugin to gold for Link Time Optimization ------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This is a gold plugin for LLVM. It provides an LLVM implementation of the |
| // interface described in http://gcc.gnu.org/wiki/whopr/driver . |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/ADT/StringSet.h" |
| #include "llvm/Analysis/TargetLibraryInfo.h" |
| #include "llvm/Analysis/TargetTransformInfo.h" |
| #include "llvm/Bitcode/ReaderWriter.h" |
| #include "llvm/CodeGen/Analysis.h" |
| #include "llvm/CodeGen/CommandFlags.h" |
| #include "llvm/CodeGen/ParallelCG.h" |
| #include "llvm/Config/config.h" // plugin-api.h requires HAVE_STDINT_H |
| #include "llvm/IR/AutoUpgrade.h" |
| #include "llvm/IR/Constants.h" |
| #include "llvm/IR/DiagnosticInfo.h" |
| #include "llvm/IR/DiagnosticPrinter.h" |
| #include "llvm/IR/LLVMContext.h" |
| #include "llvm/IR/LegacyPassManager.h" |
| #include "llvm/IR/Module.h" |
| #include "llvm/IR/Verifier.h" |
| #include "llvm/LTO/LTO.h" |
| #include "llvm/Linker/IRMover.h" |
| #include "llvm/MC/SubtargetFeature.h" |
| #include "llvm/Object/IRObjectFile.h" |
| #include "llvm/Object/ModuleSummaryIndexObjectFile.h" |
| #include "llvm/Support/Host.h" |
| #include "llvm/Support/ManagedStatic.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Support/Path.h" |
| #include "llvm/Support/TargetRegistry.h" |
| #include "llvm/Support/TargetSelect.h" |
| #include "llvm/Support/ThreadPool.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/Support/thread.h" |
| #include "llvm/Transforms/IPO.h" |
| #include "llvm/Transforms/IPO/FunctionImport.h" |
| #include "llvm/Transforms/IPO/PassManagerBuilder.h" |
| #include "llvm/Transforms/Utils/FunctionImportUtils.h" |
| #include "llvm/Transforms/Utils/GlobalStatus.h" |
| #include "llvm/Transforms/Utils/ValueMapper.h" |
| #include <list> |
| #include <plugin-api.h> |
| #include <system_error> |
| #include <utility> |
| #include <vector> |
| |
| // FIXME: remove this declaration when we stop maintaining Ubuntu Quantal and |
| // Precise and Debian Wheezy (binutils 2.23 is required) |
| #define LDPO_PIE 3 |
| |
| #define LDPT_GET_SYMBOLS_V3 28 |
| |
| using namespace llvm; |
| |
| static ld_plugin_status discard_message(int level, const char *format, ...) { |
| // Die loudly. Recent versions of Gold pass ld_plugin_message as the first |
| // callback in the transfer vector. This should never be called. |
| abort(); |
| } |
| |
| static ld_plugin_release_input_file release_input_file = nullptr; |
| static ld_plugin_get_input_file get_input_file = nullptr; |
| static ld_plugin_message message = discard_message; |
| |
| namespace { |
| struct claimed_file { |
| void *handle; |
| void *leader_handle; |
| std::vector<ld_plugin_symbol> syms; |
| off_t filesize; |
| std::string name; |
| }; |
| |
| /// RAII wrapper to manage opening and releasing of a ld_plugin_input_file. |
| struct PluginInputFile { |
| void *Handle; |
| std::unique_ptr<ld_plugin_input_file> File; |
| |
| PluginInputFile(void *Handle) : Handle(Handle) { |
| File = llvm::make_unique<ld_plugin_input_file>(); |
| if (get_input_file(Handle, File.get()) != LDPS_OK) |
| message(LDPL_FATAL, "Failed to get file information"); |
| } |
| ~PluginInputFile() { |
| // File would have been reset to nullptr if we moved this object |
| // to a new owner. |
| if (File) |
| if (release_input_file(Handle) != LDPS_OK) |
| message(LDPL_FATAL, "Failed to release file information"); |
| } |
| |
| ld_plugin_input_file &file() { return *File; } |
| |
| PluginInputFile(PluginInputFile &&RHS) = default; |
| PluginInputFile &operator=(PluginInputFile &&RHS) = default; |
| }; |
| |
| struct ResolutionInfo { |
| uint64_t CommonSize = 0; |
| unsigned CommonAlign = 0; |
| bool IsLinkonceOdr = true; |
| GlobalValue::UnnamedAddr UnnamedAddr = GlobalValue::UnnamedAddr::Global; |
| GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility; |
| bool CommonInternal = false; |
| bool UseCommon = false; |
| }; |
| |
| /// Class to own information used by a task or during its cleanup for a |
| /// ThinLTO backend instantiation. |
| class ThinLTOTaskInfo { |
| /// The output stream the task will codegen into. |
| std::unique_ptr<raw_fd_ostream> OS; |
| |
| /// The file name corresponding to the output stream, used during cleanup. |
| std::string Filename; |
| |
| /// Flag indicating whether the output file is a temp file that must be |
| /// added to the cleanup list during cleanup. |
| bool TempOutFile; |
| |
| public: |
| ThinLTOTaskInfo(std::unique_ptr<raw_fd_ostream> OS, std::string Filename, |
| bool TempOutFile) |
| : OS(std::move(OS)), Filename(std::move(Filename)), |
| TempOutFile(TempOutFile) {} |
| |
| /// Performs task related cleanup activities that must be done |
| /// single-threaded (i.e. call backs to gold). |
| void cleanup(); |
| }; |
| } |
| |
| static ld_plugin_add_symbols add_symbols = nullptr; |
| static ld_plugin_get_symbols get_symbols = nullptr; |
| static ld_plugin_add_input_file add_input_file = nullptr; |
| static ld_plugin_set_extra_library_path set_extra_library_path = nullptr; |
| static ld_plugin_get_view get_view = nullptr; |
| static Optional<Reloc::Model> RelocationModel; |
| static std::string output_name = ""; |
| static std::list<claimed_file> Modules; |
| static DenseMap<int, void *> FDToLeaderHandle; |
| static StringMap<ResolutionInfo> ResInfo; |
| static std::vector<std::string> Cleanup; |
| static llvm::TargetOptions TargetOpts; |
| static std::string DefaultTriple = sys::getDefaultTargetTriple(); |
| |
| namespace options { |
| enum OutputType { |
| OT_NORMAL, |
| OT_DISABLE, |
| OT_BC_ONLY, |
| OT_SAVE_TEMPS |
| }; |
| static bool generate_api_file = false; |
| static OutputType TheOutputType = OT_NORMAL; |
| static unsigned OptLevel = 2; |
| // Default parallelism of 0 used to indicate that user did not specify. |
| // Actual parallelism default value depends on implementation. |
| // Currently, code generation defaults to no parallelism, whereas |
| // ThinLTO uses the hardware_concurrency as the default. |
| static unsigned Parallelism = 0; |
| #ifdef NDEBUG |
| static bool DisableVerify = true; |
| #else |
| static bool DisableVerify = false; |
| #endif |
| static std::string obj_path; |
| static std::string extra_library_path; |
| static std::string triple; |
| static std::string mcpu; |
| // When the thinlto plugin option is specified, only read the function |
| // the information from intermediate files and write a combined |
| // global index for the ThinLTO backends. |
| static bool thinlto = false; |
| // If false, all ThinLTO backend compilations through code gen are performed |
| // using multiple threads in the gold-plugin, before handing control back to |
| // gold. If true, write individual backend index files which reflect |
| // the import decisions, and exit afterwards. The assumption is |
| // that the build system will launch the backend processes. |
| static bool thinlto_index_only = false; |
| // If true, when generating individual index files for distributed backends, |
| // also generate a "${bitcodefile}.imports" file at the same location for each |
| // bitcode file, listing the files it imports from in plain text. This is to |
| // support distributed build file staging. |
| static bool thinlto_emit_imports_files = false; |
| // Option to control where files for a distributed backend (the individual |
| // index files and optional imports files) are created. |
| // If specified, expects a string of the form "oldprefix:newprefix", and |
| // instead of generating these files in the same directory path as the |
| // corresponding bitcode file, will use a path formed by replacing the |
| // bitcode file's path prefix matching oldprefix with newprefix. |
| static std::string thinlto_prefix_replace; |
| // Additional options to pass into the code generator. |
| // Note: This array will contain all plugin options which are not claimed |
| // as plugin exclusive to pass to the code generator. |
| // For example, "generate-api-file" and "as"options are for the plugin |
| // use only and will not be passed. |
| static std::vector<const char *> extra; |
| |
| static void process_plugin_option(const char *opt_) |
| { |
| if (opt_ == nullptr) |
| return; |
| llvm::StringRef opt = opt_; |
| |
| if (opt == "generate-api-file") { |
| generate_api_file = true; |
| } else if (opt.startswith("mcpu=")) { |
| mcpu = opt.substr(strlen("mcpu=")); |
| } else if (opt.startswith("extra-library-path=")) { |
| extra_library_path = opt.substr(strlen("extra_library_path=")); |
| } else if (opt.startswith("mtriple=")) { |
| triple = opt.substr(strlen("mtriple=")); |
| } else if (opt.startswith("obj-path=")) { |
| obj_path = opt.substr(strlen("obj-path=")); |
| } else if (opt == "emit-llvm") { |
| TheOutputType = OT_BC_ONLY; |
| } else if (opt == "save-temps") { |
| TheOutputType = OT_SAVE_TEMPS; |
| } else if (opt == "disable-output") { |
| TheOutputType = OT_DISABLE; |
| } else if (opt == "thinlto") { |
| thinlto = true; |
| } else if (opt == "thinlto-index-only") { |
| thinlto_index_only = true; |
| } else if (opt == "thinlto-emit-imports-files") { |
| thinlto_emit_imports_files = true; |
| } else if (opt.startswith("thinlto-prefix-replace=")) { |
| thinlto_prefix_replace = opt.substr(strlen("thinlto-prefix-replace=")); |
| if (thinlto_prefix_replace.find(";") == std::string::npos) |
| message(LDPL_FATAL, "thinlto-prefix-replace expects 'old;new' format"); |
| } else if (opt.size() == 2 && opt[0] == 'O') { |
| if (opt[1] < '0' || opt[1] > '3') |
| message(LDPL_FATAL, "Optimization level must be between 0 and 3"); |
| OptLevel = opt[1] - '0'; |
| } else if (opt.startswith("jobs=")) { |
| if (StringRef(opt_ + 5).getAsInteger(10, Parallelism)) |
| message(LDPL_FATAL, "Invalid parallelism level: %s", opt_ + 5); |
| } else if (opt == "disable-verify") { |
| DisableVerify = true; |
| } else { |
| // Save this option to pass to the code generator. |
| // ParseCommandLineOptions() expects argv[0] to be program name. Lazily |
| // add that. |
| if (extra.empty()) |
| extra.push_back("LLVMgold"); |
| |
| extra.push_back(opt_); |
| } |
| } |
| } |
| |
| static ld_plugin_status claim_file_hook(const ld_plugin_input_file *file, |
| int *claimed); |
| static ld_plugin_status all_symbols_read_hook(void); |
| static ld_plugin_status cleanup_hook(void); |
| |
| extern "C" ld_plugin_status onload(ld_plugin_tv *tv); |
| ld_plugin_status onload(ld_plugin_tv *tv) { |
| InitializeAllTargetInfos(); |
| InitializeAllTargets(); |
| InitializeAllTargetMCs(); |
| InitializeAllAsmParsers(); |
| InitializeAllAsmPrinters(); |
| |
| // We're given a pointer to the first transfer vector. We read through them |
| // until we find one where tv_tag == LDPT_NULL. The REGISTER_* tagged values |
| // contain pointers to functions that we need to call to register our own |
| // hooks. The others are addresses of functions we can use to call into gold |
| // for services. |
| |
| bool registeredClaimFile = false; |
| bool RegisteredAllSymbolsRead = false; |
| |
| for (; tv->tv_tag != LDPT_NULL; ++tv) { |
| // Cast tv_tag to int to allow values not in "enum ld_plugin_tag", like, for |
| // example, LDPT_GET_SYMBOLS_V3 when building against an older plugin-api.h |
| // header. |
| switch (static_cast<int>(tv->tv_tag)) { |
| case LDPT_OUTPUT_NAME: |
| output_name = tv->tv_u.tv_string; |
| break; |
| case LDPT_LINKER_OUTPUT: |
| switch (tv->tv_u.tv_val) { |
| case LDPO_REL: // .o |
| case LDPO_DYN: // .so |
| case LDPO_PIE: // position independent executable |
| RelocationModel = Reloc::PIC_; |
| break; |
| case LDPO_EXEC: // .exe |
| RelocationModel = Reloc::Static; |
| break; |
| default: |
| message(LDPL_ERROR, "Unknown output file type %d", tv->tv_u.tv_val); |
| return LDPS_ERR; |
| } |
| break; |
| case LDPT_OPTION: |
| options::process_plugin_option(tv->tv_u.tv_string); |
| break; |
| case LDPT_REGISTER_CLAIM_FILE_HOOK: { |
| ld_plugin_register_claim_file callback; |
| callback = tv->tv_u.tv_register_claim_file; |
| |
| if (callback(claim_file_hook) != LDPS_OK) |
| return LDPS_ERR; |
| |
| registeredClaimFile = true; |
| } break; |
| case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK: { |
| ld_plugin_register_all_symbols_read callback; |
| callback = tv->tv_u.tv_register_all_symbols_read; |
| |
| if (callback(all_symbols_read_hook) != LDPS_OK) |
| return LDPS_ERR; |
| |
| RegisteredAllSymbolsRead = true; |
| } break; |
| case LDPT_REGISTER_CLEANUP_HOOK: { |
| ld_plugin_register_cleanup callback; |
| callback = tv->tv_u.tv_register_cleanup; |
| |
| if (callback(cleanup_hook) != LDPS_OK) |
| return LDPS_ERR; |
| } break; |
| case LDPT_GET_INPUT_FILE: |
| get_input_file = tv->tv_u.tv_get_input_file; |
| break; |
| case LDPT_RELEASE_INPUT_FILE: |
| release_input_file = tv->tv_u.tv_release_input_file; |
| break; |
| case LDPT_ADD_SYMBOLS: |
| add_symbols = tv->tv_u.tv_add_symbols; |
| break; |
| case LDPT_GET_SYMBOLS_V2: |
| // Do not override get_symbols_v3 with get_symbols_v2. |
| if (!get_symbols) |
| get_symbols = tv->tv_u.tv_get_symbols; |
| break; |
| case LDPT_GET_SYMBOLS_V3: |
| get_symbols = tv->tv_u.tv_get_symbols; |
| break; |
| case LDPT_ADD_INPUT_FILE: |
| add_input_file = tv->tv_u.tv_add_input_file; |
| break; |
| case LDPT_SET_EXTRA_LIBRARY_PATH: |
| set_extra_library_path = tv->tv_u.tv_set_extra_library_path; |
| break; |
| case LDPT_GET_VIEW: |
| get_view = tv->tv_u.tv_get_view; |
| break; |
| case LDPT_MESSAGE: |
| message = tv->tv_u.tv_message; |
| break; |
| default: |
| break; |
| } |
| } |
| |
| if (!registeredClaimFile) { |
| message(LDPL_ERROR, "register_claim_file not passed to LLVMgold."); |
| return LDPS_ERR; |
| } |
| if (!add_symbols) { |
| message(LDPL_ERROR, "add_symbols not passed to LLVMgold."); |
| return LDPS_ERR; |
| } |
| |
| if (!RegisteredAllSymbolsRead) |
| return LDPS_OK; |
| |
| if (!get_input_file) { |
| message(LDPL_ERROR, "get_input_file not passed to LLVMgold."); |
| return LDPS_ERR; |
| } |
| if (!release_input_file) { |
| message(LDPL_ERROR, "release_input_file not passed to LLVMgold."); |
| return LDPS_ERR; |
| } |
| |
| return LDPS_OK; |
| } |
| |
| static const GlobalObject *getBaseObject(const GlobalValue &GV) { |
| if (auto *GA = dyn_cast<GlobalAlias>(&GV)) |
| return GA->getBaseObject(); |
| return cast<GlobalObject>(&GV); |
| } |
| |
| static bool shouldSkip(uint32_t Symflags) { |
| if (!(Symflags & object::BasicSymbolRef::SF_Global)) |
| return true; |
| if (Symflags & object::BasicSymbolRef::SF_FormatSpecific) |
| return true; |
| return false; |
| } |
| |
| static void diagnosticHandler(const DiagnosticInfo &DI) { |
| if (const auto *BDI = dyn_cast<BitcodeDiagnosticInfo>(&DI)) { |
| std::error_code EC = BDI->getError(); |
| if (EC == BitcodeError::InvalidBitcodeSignature) |
| return; |
| } |
| |
| std::string ErrStorage; |
| { |
| raw_string_ostream OS(ErrStorage); |
| DiagnosticPrinterRawOStream DP(OS); |
| DI.print(DP); |
| } |
| ld_plugin_level Level; |
| switch (DI.getSeverity()) { |
| case DS_Error: |
| message(LDPL_FATAL, "LLVM gold plugin has failed to create LTO module: %s", |
| ErrStorage.c_str()); |
| case DS_Warning: |
| Level = LDPL_WARNING; |
| break; |
| case DS_Note: |
| case DS_Remark: |
| Level = LDPL_INFO; |
| break; |
| } |
| message(Level, "LLVM gold plugin: %s", ErrStorage.c_str()); |
| } |
| |
| static void diagnosticHandlerForContext(const DiagnosticInfo &DI, |
| void *Context) { |
| diagnosticHandler(DI); |
| } |
| |
| static GlobalValue::VisibilityTypes |
| getMinVisibility(GlobalValue::VisibilityTypes A, |
| GlobalValue::VisibilityTypes B) { |
| if (A == GlobalValue::HiddenVisibility) |
| return A; |
| if (B == GlobalValue::HiddenVisibility) |
| return B; |
| if (A == GlobalValue::ProtectedVisibility) |
| return A; |
| return B; |
| } |
| |
| /// Called by gold to see whether this file is one that our plugin can handle. |
| /// We'll try to open it and register all the symbols with add_symbol if |
| /// possible. |
| static ld_plugin_status claim_file_hook(const ld_plugin_input_file *file, |
| int *claimed) { |
| LLVMContext Context; |
| MemoryBufferRef BufferRef; |
| std::unique_ptr<MemoryBuffer> Buffer; |
| if (get_view) { |
| const void *view; |
| if (get_view(file->handle, &view) != LDPS_OK) { |
| message(LDPL_ERROR, "Failed to get a view of %s", file->name); |
| return LDPS_ERR; |
| } |
| BufferRef = |
| MemoryBufferRef(StringRef((const char *)view, file->filesize), ""); |
| } else { |
| int64_t offset = 0; |
| // Gold has found what might be IR part-way inside of a file, such as |
| // an .a archive. |
| if (file->offset) { |
| offset = file->offset; |
| } |
| ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr = |
| MemoryBuffer::getOpenFileSlice(file->fd, file->name, file->filesize, |
| offset); |
| if (std::error_code EC = BufferOrErr.getError()) { |
| message(LDPL_ERROR, EC.message().c_str()); |
| return LDPS_ERR; |
| } |
| Buffer = std::move(BufferOrErr.get()); |
| BufferRef = Buffer->getMemBufferRef(); |
| } |
| |
| Context.setDiagnosticHandler(diagnosticHandlerForContext); |
| ErrorOr<std::unique_ptr<object::IRObjectFile>> ObjOrErr = |
| object::IRObjectFile::create(BufferRef, Context); |
| std::error_code EC = ObjOrErr.getError(); |
| if (EC == object::object_error::invalid_file_type || |
| EC == object::object_error::bitcode_section_not_found) |
| return LDPS_OK; |
| |
| *claimed = 1; |
| |
| if (EC) { |
| message(LDPL_ERROR, "LLVM gold plugin has failed to create LTO module: %s", |
| EC.message().c_str()); |
| return LDPS_ERR; |
| } |
| std::unique_ptr<object::IRObjectFile> Obj = std::move(*ObjOrErr); |
| |
| Modules.resize(Modules.size() + 1); |
| claimed_file &cf = Modules.back(); |
| |
| cf.handle = file->handle; |
| // Keep track of the first handle for each file descriptor, since there are |
| // multiple in the case of an archive. This is used later in the case of |
| // ThinLTO parallel backends to ensure that each file is only opened and |
| // released once. |
| auto LeaderHandle = |
| FDToLeaderHandle.insert(std::make_pair(file->fd, file->handle)).first; |
| cf.leader_handle = LeaderHandle->second; |
| // Save the filesize since for parallel ThinLTO backends we can only |
| // invoke get_input_file once per archive (only for the leader handle). |
| cf.filesize = file->filesize; |
| // In the case of an archive library, all but the first member must have a |
| // non-zero offset, which we can append to the file name to obtain a |
| // unique name. |
| cf.name = file->name; |
| if (file->offset) |
| cf.name += ".llvm." + std::to_string(file->offset) + "." + |
| sys::path::filename(Obj->getModule().getSourceFileName()).str(); |
| |
| for (auto &Sym : Obj->symbols()) { |
| uint32_t Symflags = Sym.getFlags(); |
| if (shouldSkip(Symflags)) |
| continue; |
| |
| cf.syms.push_back(ld_plugin_symbol()); |
| ld_plugin_symbol &sym = cf.syms.back(); |
| sym.version = nullptr; |
| |
| SmallString<64> Name; |
| { |
| raw_svector_ostream OS(Name); |
| Sym.printName(OS); |
| } |
| sym.name = strdup(Name.c_str()); |
| |
| const GlobalValue *GV = Obj->getSymbolGV(Sym.getRawDataRefImpl()); |
| |
| ResolutionInfo &Res = ResInfo[sym.name]; |
| |
| sym.visibility = LDPV_DEFAULT; |
| if (GV) { |
| Res.UnnamedAddr = |
| GlobalValue::getMinUnnamedAddr(Res.UnnamedAddr, GV->getUnnamedAddr()); |
| Res.IsLinkonceOdr &= GV->hasLinkOnceLinkage(); |
| Res.Visibility = getMinVisibility(Res.Visibility, GV->getVisibility()); |
| switch (GV->getVisibility()) { |
| case GlobalValue::DefaultVisibility: |
| break; |
| case GlobalValue::HiddenVisibility: |
| sym.visibility = LDPV_HIDDEN; |
| break; |
| case GlobalValue::ProtectedVisibility: |
| sym.visibility = LDPV_PROTECTED; |
| break; |
| } |
| } |
| |
| if (Symflags & object::BasicSymbolRef::SF_Undefined) { |
| sym.def = LDPK_UNDEF; |
| if (GV && GV->hasExternalWeakLinkage()) |
| sym.def = LDPK_WEAKUNDEF; |
| } else { |
| sym.def = LDPK_DEF; |
| if (GV) { |
| assert(!GV->hasExternalWeakLinkage() && |
| !GV->hasAvailableExternallyLinkage() && "Not a declaration!"); |
| if (GV->hasCommonLinkage()) |
| sym.def = LDPK_COMMON; |
| else if (GV->isWeakForLinker()) |
| sym.def = LDPK_WEAKDEF; |
| } |
| } |
| |
| sym.size = 0; |
| sym.comdat_key = nullptr; |
| if (GV) { |
| const GlobalObject *Base = getBaseObject(*GV); |
| if (!Base) |
| message(LDPL_FATAL, "Unable to determine comdat of alias!"); |
| const Comdat *C = Base->getComdat(); |
| if (C) |
| sym.comdat_key = strdup(C->getName().str().c_str()); |
| } |
| |
| sym.resolution = LDPR_UNKNOWN; |
| } |
| |
| if (!cf.syms.empty()) { |
| if (add_symbols(cf.handle, cf.syms.size(), cf.syms.data()) != LDPS_OK) { |
| message(LDPL_ERROR, "Unable to add symbols!"); |
| return LDPS_ERR; |
| } |
| } |
| |
| return LDPS_OK; |
| } |
| |
| static void internalize(GlobalValue &GV) { |
| if (GV.isDeclarationForLinker()) |
| return; // We get here if there is a matching asm definition. |
| if (!GV.hasLocalLinkage()) |
| GV.setLinkage(GlobalValue::InternalLinkage); |
| } |
| |
| static const char *getResolutionName(ld_plugin_symbol_resolution R) { |
| switch (R) { |
| case LDPR_UNKNOWN: |
| return "UNKNOWN"; |
| case LDPR_UNDEF: |
| return "UNDEF"; |
| case LDPR_PREVAILING_DEF: |
| return "PREVAILING_DEF"; |
| case LDPR_PREVAILING_DEF_IRONLY: |
| return "PREVAILING_DEF_IRONLY"; |
| case LDPR_PREEMPTED_REG: |
| return "PREEMPTED_REG"; |
| case LDPR_PREEMPTED_IR: |
| return "PREEMPTED_IR"; |
| case LDPR_RESOLVED_IR: |
| return "RESOLVED_IR"; |
| case LDPR_RESOLVED_EXEC: |
| return "RESOLVED_EXEC"; |
| case LDPR_RESOLVED_DYN: |
| return "RESOLVED_DYN"; |
| case LDPR_PREVAILING_DEF_IRONLY_EXP: |
| return "PREVAILING_DEF_IRONLY_EXP"; |
| } |
| llvm_unreachable("Unknown resolution"); |
| } |
| |
| static void freeSymName(ld_plugin_symbol &Sym) { |
| free(Sym.name); |
| free(Sym.comdat_key); |
| Sym.name = nullptr; |
| Sym.comdat_key = nullptr; |
| } |
| |
| /// Helper to get a file's symbols and a view into it via gold callbacks. |
| static const void *getSymbolsAndView(claimed_file &F) { |
| ld_plugin_status status = get_symbols(F.handle, F.syms.size(), F.syms.data()); |
| if (status == LDPS_NO_SYMS) |
| return nullptr; |
| |
| if (status != LDPS_OK) |
| message(LDPL_FATAL, "Failed to get symbol information"); |
| |
| const void *View; |
| if (get_view(F.handle, &View) != LDPS_OK) |
| message(LDPL_FATAL, "Failed to get a view of file"); |
| |
| return View; |
| } |
| |
| static std::unique_ptr<ModuleSummaryIndex> |
| getModuleSummaryIndexForFile(claimed_file &F) { |
| const void *View = getSymbolsAndView(F); |
| if (!View) |
| return nullptr; |
| |
| MemoryBufferRef BufferRef(StringRef((const char *)View, F.filesize), F.name); |
| |
| // Don't bother trying to build an index if there is no summary information |
| // in this bitcode file. |
| if (!object::ModuleSummaryIndexObjectFile::hasGlobalValueSummaryInMemBuffer( |
| BufferRef, diagnosticHandler)) |
| return std::unique_ptr<ModuleSummaryIndex>(nullptr); |
| |
| ErrorOr<std::unique_ptr<object::ModuleSummaryIndexObjectFile>> ObjOrErr = |
| object::ModuleSummaryIndexObjectFile::create(BufferRef, |
| diagnosticHandler); |
| |
| if (std::error_code EC = ObjOrErr.getError()) |
| message(LDPL_FATAL, |
| "Could not read module summary index bitcode from file : %s", |
| EC.message().c_str()); |
| |
| object::ModuleSummaryIndexObjectFile &Obj = **ObjOrErr; |
| |
| return Obj.takeIndex(); |
| } |
| |
| static std::unique_ptr<Module> |
| getModuleForFile(LLVMContext &Context, claimed_file &F, const void *View, |
| StringRef Name, raw_fd_ostream *ApiFile, |
| StringSet<> &Internalize, std::vector<GlobalValue *> &Keep, |
| StringMap<unsigned> &Realign) { |
| MemoryBufferRef BufferRef(StringRef((const char *)View, F.filesize), Name); |
| ErrorOr<std::unique_ptr<object::IRObjectFile>> ObjOrErr = |
| object::IRObjectFile::create(BufferRef, Context); |
| |
| if (std::error_code EC = ObjOrErr.getError()) |
| message(LDPL_FATAL, "Could not read bitcode from file : %s", |
| EC.message().c_str()); |
| |
| object::IRObjectFile &Obj = **ObjOrErr; |
| |
| Module &M = Obj.getModule(); |
| |
| M.materializeMetadata(); |
| UpgradeDebugInfo(M); |
| |
| SmallPtrSet<GlobalValue *, 8> Used; |
| collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ false); |
| |
| unsigned SymNum = 0; |
| for (auto &ObjSym : Obj.symbols()) { |
| GlobalValue *GV = Obj.getSymbolGV(ObjSym.getRawDataRefImpl()); |
| if (GV && GV->hasAppendingLinkage()) |
| Keep.push_back(GV); |
| |
| if (shouldSkip(ObjSym.getFlags())) |
| continue; |
| ld_plugin_symbol &Sym = F.syms[SymNum]; |
| ++SymNum; |
| |
| ld_plugin_symbol_resolution Resolution = |
| (ld_plugin_symbol_resolution)Sym.resolution; |
| |
| if (options::generate_api_file) |
| *ApiFile << Sym.name << ' ' << getResolutionName(Resolution) << '\n'; |
| |
| if (!GV) { |
| freeSymName(Sym); |
| continue; // Asm symbol. |
| } |
| |
| ResolutionInfo &Res = ResInfo[Sym.name]; |
| if (Resolution == LDPR_PREVAILING_DEF_IRONLY_EXP && !Res.IsLinkonceOdr) |
| Resolution = LDPR_PREVAILING_DEF; |
| |
| GV->setUnnamedAddr(Res.UnnamedAddr); |
| GV->setVisibility(Res.Visibility); |
| |
| // Override gold's resolution for common symbols. We want the largest |
| // one to win. |
| if (GV->hasCommonLinkage()) { |
| if (Resolution == LDPR_PREVAILING_DEF_IRONLY) |
| Res.CommonInternal = true; |
| |
| if (Resolution == LDPR_PREVAILING_DEF_IRONLY || |
| Resolution == LDPR_PREVAILING_DEF) |
| Res.UseCommon = true; |
| |
| const DataLayout &DL = GV->getParent()->getDataLayout(); |
| uint64_t Size = DL.getTypeAllocSize(GV->getType()->getElementType()); |
| unsigned Align = GV->getAlignment(); |
| |
| if (Res.UseCommon && Size >= Res.CommonSize) { |
| // Take GV. |
| if (Res.CommonInternal) |
| Resolution = LDPR_PREVAILING_DEF_IRONLY; |
| else |
| Resolution = LDPR_PREVAILING_DEF; |
| cast<GlobalVariable>(GV)->setAlignment( |
| std::max(Res.CommonAlign, Align)); |
| } else { |
| // Do not take GV, it's smaller than what we already have in the |
| // combined module. |
| Resolution = LDPR_PREEMPTED_IR; |
| if (Align > Res.CommonAlign) |
| // Need to raise the alignment though. |
| Realign[Sym.name] = Align; |
| } |
| |
| Res.CommonSize = std::max(Res.CommonSize, Size); |
| Res.CommonAlign = std::max(Res.CommonAlign, Align); |
| } |
| |
| switch (Resolution) { |
| case LDPR_UNKNOWN: |
| llvm_unreachable("Unexpected resolution"); |
| |
| case LDPR_RESOLVED_IR: |
| case LDPR_RESOLVED_EXEC: |
| case LDPR_RESOLVED_DYN: |
| case LDPR_PREEMPTED_IR: |
| case LDPR_PREEMPTED_REG: |
| break; |
| |
| case LDPR_UNDEF: |
| if (!GV->isDeclarationForLinker()) |
| assert(GV->hasComdat()); |
| break; |
| |
| case LDPR_PREVAILING_DEF_IRONLY: { |
| Keep.push_back(GV); |
| // The IR linker has to be able to map this value to a declaration, |
| // so we can only internalize after linking. |
| if (!Used.count(GV)) |
| Internalize.insert(GV->getName()); |
| break; |
| } |
| |
| case LDPR_PREVAILING_DEF: |
| Keep.push_back(GV); |
| // There is a non IR use, so we have to force optimizations to keep this. |
| switch (GV->getLinkage()) { |
| default: |
| break; |
| case GlobalValue::LinkOnceAnyLinkage: |
| GV->setLinkage(GlobalValue::WeakAnyLinkage); |
| break; |
| case GlobalValue::LinkOnceODRLinkage: |
| GV->setLinkage(GlobalValue::WeakODRLinkage); |
| break; |
| } |
| break; |
| |
| case LDPR_PREVAILING_DEF_IRONLY_EXP: { |
| Keep.push_back(GV); |
| if (canBeOmittedFromSymbolTable(GV)) |
| Internalize.insert(GV->getName()); |
| break; |
| } |
| } |
| |
| freeSymName(Sym); |
| } |
| |
| return Obj.takeModule(); |
| } |
| |
| static void saveBCFile(StringRef Path, Module &M) { |
| std::error_code EC; |
| raw_fd_ostream OS(Path, EC, sys::fs::OpenFlags::F_None); |
| if (EC) |
| message(LDPL_FATAL, "Failed to write the output file."); |
| WriteBitcodeToFile(&M, OS, /* ShouldPreserveUseListOrder */ false); |
| } |
| |
| static void recordFile(std::string Filename, bool TempOutFile) { |
| if (add_input_file(Filename.c_str()) != LDPS_OK) |
| message(LDPL_FATAL, |
| "Unable to add .o file to the link. File left behind in: %s", |
| Filename.c_str()); |
| if (TempOutFile) |
| Cleanup.push_back(Filename.c_str()); |
| } |
| |
| void ThinLTOTaskInfo::cleanup() { |
| // Close the output file descriptor before we pass it to gold. |
| OS->close(); |
| |
| recordFile(Filename, TempOutFile); |
| } |
| |
| namespace { |
| /// Class to manage optimization and code generation for a module, possibly |
| /// in a thread (ThinLTO). |
| class CodeGen { |
| /// The module for which this will generate code. |
| std::unique_ptr<llvm::Module> M; |
| |
| /// The output stream to generate code into. |
| raw_fd_ostream *OS; |
| |
| /// The task ID when this was invoked in a thread (ThinLTO). |
| int TaskID; |
| |
| /// The module summary index for ThinLTO tasks. |
| const ModuleSummaryIndex *CombinedIndex; |
| |
| /// The target machine for generating code for this module. |
| std::unique_ptr<TargetMachine> TM; |
| |
| /// Filename to use as base when save-temps is enabled, used to get |
| /// a unique and identifiable save-temps output file for each ThinLTO backend. |
| std::string SaveTempsFilename; |
| |
| /// Map from a module name to the corresponding buffer holding a view of the |
| /// bitcode provided via the get_view gold callback. |
| StringMap<MemoryBufferRef> *ModuleMap; |
| |
| // Functions to import into this module. |
| FunctionImporter::ImportMapTy *ImportList; |
| |
| // Map of globals defined in this module to their summary. |
| std::map<GlobalValue::GUID, GlobalValueSummary *> *DefinedGlobals; |
| |
| public: |
| /// Constructor used by full LTO. |
| CodeGen(std::unique_ptr<llvm::Module> M) |
| : M(std::move(M)), OS(nullptr), TaskID(-1), CombinedIndex(nullptr), |
| ModuleMap(nullptr) { |
| initTargetMachine(); |
| } |
| /// Constructor used by ThinLTO. |
| CodeGen(std::unique_ptr<llvm::Module> M, raw_fd_ostream *OS, int TaskID, |
| const ModuleSummaryIndex *CombinedIndex, std::string Filename, |
| StringMap<MemoryBufferRef> *ModuleMap, |
| FunctionImporter::ImportMapTy *ImportList, |
| std::map<GlobalValue::GUID, GlobalValueSummary *> *DefinedGlobals) |
| : M(std::move(M)), OS(OS), TaskID(TaskID), CombinedIndex(CombinedIndex), |
| SaveTempsFilename(std::move(Filename)), ModuleMap(ModuleMap), |
| ImportList(ImportList), DefinedGlobals(DefinedGlobals) { |
| assert(options::thinlto == !!CombinedIndex && |
| "Expected module summary index iff performing ThinLTO"); |
| initTargetMachine(); |
| } |
| |
| /// Invoke LTO passes and the code generator for the module. |
| void runAll(); |
| |
| /// Invoke the actual code generation to emit Module's object to file. |
| void runCodegenPasses(); |
| |
| private: |
| const Target *TheTarget; |
| std::string TripleStr; |
| std::string FeaturesString; |
| TargetOptions Options; |
| |
| /// Create a target machine for the module. Must be unique for each |
| /// module/task. |
| void initTargetMachine(); |
| |
| std::unique_ptr<TargetMachine> createTargetMachine(); |
| |
| /// Run all LTO passes on the module. |
| void runLTOPasses(); |
| |
| /// Sets up output files necessary to perform optional multi-threaded |
| /// split code generation, and invokes the code generation implementation. |
| /// If BCFileName is not empty, saves bitcode for module partitions into |
| /// {BCFileName}0 .. {BCFileName}N. |
| void runSplitCodeGen(const SmallString<128> &BCFilename); |
| }; |
| } |
| |
| static SubtargetFeatures getFeatures(Triple &TheTriple) { |
| SubtargetFeatures Features; |
| Features.getDefaultSubtargetFeatures(TheTriple); |
| for (const std::string &A : MAttrs) |
| Features.AddFeature(A); |
| return Features; |
| } |
| |
| static CodeGenOpt::Level getCGOptLevel() { |
| switch (options::OptLevel) { |
| case 0: |
| return CodeGenOpt::None; |
| case 1: |
| return CodeGenOpt::Less; |
| case 2: |
| return CodeGenOpt::Default; |
| case 3: |
| return CodeGenOpt::Aggressive; |
| } |
| llvm_unreachable("Invalid optimization level"); |
| } |
| |
| void CodeGen::initTargetMachine() { |
| TripleStr = M->getTargetTriple(); |
| Triple TheTriple(TripleStr); |
| |
| std::string ErrMsg; |
| TheTarget = TargetRegistry::lookupTarget(TripleStr, ErrMsg); |
| if (!TheTarget) |
| message(LDPL_FATAL, "Target not found: %s", ErrMsg.c_str()); |
| |
| SubtargetFeatures Features = getFeatures(TheTriple); |
| FeaturesString = Features.getString(); |
| Options = InitTargetOptionsFromCodeGenFlags(); |
| |
| // Disable the new X86 relax relocations since gold might not support them. |
| // FIXME: Check the gold version or add a new option to enable them. |
| Options.RelaxELFRelocations = false; |
| |
| TM = createTargetMachine(); |
| } |
| |
| std::unique_ptr<TargetMachine> CodeGen::createTargetMachine() { |
| CodeGenOpt::Level CGOptLevel = getCGOptLevel(); |
| |
| return std::unique_ptr<TargetMachine>(TheTarget->createTargetMachine( |
| TripleStr, options::mcpu, FeaturesString, Options, RelocationModel, |
| CodeModel::Default, CGOptLevel)); |
| } |
| |
| void CodeGen::runLTOPasses() { |
| M->setDataLayout(TM->createDataLayout()); |
| |
| if (CombinedIndex) { |
| // Apply summary-based LinkOnce/Weak resolution decisions. |
| thinLTOResolveWeakForLinkerModule(*M, *DefinedGlobals); |
| |
| // Apply summary-based internalization decisions. Skip if there are no |
| // defined globals from the summary since not only is it unnecessary, but |
| // if this module did not have a summary section the internalizer will |
| // assert if it finds any definitions in this module that aren't in the |
| // DefinedGlobals set. |
| if (!DefinedGlobals->empty()) |
| thinLTOInternalizeModule(*M, *DefinedGlobals); |
| |
| // Create a loader that will parse the bitcode from the buffers |
| // in the ModuleMap. |
| ModuleLoader Loader(M->getContext(), *ModuleMap); |
| |
| // Perform function importing. |
| FunctionImporter Importer(*CombinedIndex, Loader); |
| Importer.importFunctions(*M, *ImportList); |
| } |
| |
| legacy::PassManager passes; |
| passes.add(createTargetTransformInfoWrapperPass(TM->getTargetIRAnalysis())); |
| |
| PassManagerBuilder PMB; |
| PMB.LibraryInfo = new TargetLibraryInfoImpl(Triple(TM->getTargetTriple())); |
| PMB.Inliner = createFunctionInliningPass(); |
| // Unconditionally verify input since it is not verified before this |
| // point and has unknown origin. |
| PMB.VerifyInput = true; |
| PMB.VerifyOutput = !options::DisableVerify; |
| PMB.LoopVectorize = true; |
| PMB.SLPVectorize = true; |
| PMB.OptLevel = options::OptLevel; |
| if (options::thinlto) |
| PMB.populateThinLTOPassManager(passes); |
| else |
| PMB.populateLTOPassManager(passes); |
| passes.run(*M); |
| } |
| |
| /// Open a file and return the new file descriptor given a base input |
| /// file name, a flag indicating whether a temp file should be generated, |
| /// and an optional task id. The new filename generated is |
| /// returned in \p NewFilename. |
| static int openOutputFile(SmallString<128> InFilename, bool TempOutFile, |
| SmallString<128> &NewFilename, int TaskID = -1) { |
| int FD; |
| if (TempOutFile) { |
| std::error_code EC = |
| sys::fs::createTemporaryFile("lto-llvm", "o", FD, NewFilename); |
| if (EC) |
| message(LDPL_FATAL, "Could not create temporary file: %s", |
| EC.message().c_str()); |
| } else { |
| NewFilename = InFilename; |
| if (TaskID >= 0) |
| NewFilename += utostr(TaskID); |
| std::error_code EC = |
| sys::fs::openFileForWrite(NewFilename, FD, sys::fs::F_None); |
| if (EC) |
| message(LDPL_FATAL, "Could not open file: %s", EC.message().c_str()); |
| } |
| return FD; |
| } |
| |
| void CodeGen::runCodegenPasses() { |
| assert(OS && "Output stream must be set before emitting to file"); |
| legacy::PassManager CodeGenPasses; |
| if (TM->addPassesToEmitFile(CodeGenPasses, *OS, |
| TargetMachine::CGFT_ObjectFile)) |
| report_fatal_error("Failed to setup codegen"); |
| CodeGenPasses.run(*M); |
| } |
| |
| void CodeGen::runSplitCodeGen(const SmallString<128> &BCFilename) { |
| SmallString<128> Filename; |
| // Note that openOutputFile will append a unique ID for each task |
| if (!options::obj_path.empty()) |
| Filename = options::obj_path; |
| else if (options::TheOutputType == options::OT_SAVE_TEMPS) |
| Filename = output_name + ".o"; |
| |
| // Note that the default parallelism is 1 instead of the |
| // hardware_concurrency, as there are behavioral differences between |
| // parallelism levels (e.g. symbol ordering will be different, and some uses |
| // of inline asm currently have issues with parallelism >1). |
| unsigned int MaxThreads = options::Parallelism ? options::Parallelism : 1; |
| |
| std::vector<SmallString<128>> Filenames(MaxThreads); |
| std::vector<SmallString<128>> BCFilenames(MaxThreads); |
| bool TempOutFile = Filename.empty(); |
| { |
| // Open a file descriptor for each backend task. This is done in a block |
| // so that the output file descriptors are closed before gold opens them. |
| std::list<llvm::raw_fd_ostream> OSs; |
| std::vector<llvm::raw_pwrite_stream *> OSPtrs(MaxThreads); |
| for (unsigned I = 0; I != MaxThreads; ++I) { |
| int FD = openOutputFile(Filename, TempOutFile, Filenames[I], |
| // Only append ID if there are multiple tasks. |
| MaxThreads > 1 ? I : -1); |
| OSs.emplace_back(FD, true); |
| OSPtrs[I] = &OSs.back(); |
| } |
| |
| std::list<llvm::raw_fd_ostream> BCOSs; |
| std::vector<llvm::raw_pwrite_stream *> BCOSPtrs; |
| if (!BCFilename.empty() && MaxThreads > 1) { |
| for (unsigned I = 0; I != MaxThreads; ++I) { |
| int FD = openOutputFile(BCFilename, false, BCFilenames[I], I); |
| BCOSs.emplace_back(FD, true); |
| BCOSPtrs.push_back(&BCOSs.back()); |
| } |
| } |
| |
| // Run backend tasks. |
| splitCodeGen(std::move(M), OSPtrs, BCOSPtrs, |
| [&]() { return createTargetMachine(); }); |
| } |
| |
| for (auto &Filename : Filenames) |
| recordFile(Filename.c_str(), TempOutFile); |
| } |
| |
| void CodeGen::runAll() { |
| runLTOPasses(); |
| |
| SmallString<128> OptFilename; |
| if (options::TheOutputType == options::OT_SAVE_TEMPS) { |
| OptFilename = output_name; |
| // If the CodeGen client provided a filename, use it. Always expect |
| // a provided filename if we are in a task (i.e. ThinLTO backend). |
| assert(!SaveTempsFilename.empty() || TaskID == -1); |
| if (!SaveTempsFilename.empty()) |
| OptFilename = SaveTempsFilename; |
| OptFilename += ".opt.bc"; |
| saveBCFile(OptFilename, *M); |
| } |
| |
| // If we are already in a thread (i.e. ThinLTO), just perform |
| // codegen passes directly. |
| if (TaskID >= 0) |
| runCodegenPasses(); |
| // Otherwise attempt split code gen. |
| else |
| runSplitCodeGen(OptFilename); |
| } |
| |
| /// Links the module in \p View from file \p F into the combined module |
| /// saved in the IRMover \p L. |
| static void linkInModule(LLVMContext &Context, IRMover &L, claimed_file &F, |
| const void *View, StringRef Name, |
| raw_fd_ostream *ApiFile, StringSet<> &Internalize, |
| bool SetName = false) { |
| std::vector<GlobalValue *> Keep; |
| StringMap<unsigned> Realign; |
| std::unique_ptr<Module> M = getModuleForFile(Context, F, View, Name, ApiFile, |
| Internalize, Keep, Realign); |
| if (!M.get()) |
| return; |
| if (!options::triple.empty()) |
| M->setTargetTriple(options::triple.c_str()); |
| else if (M->getTargetTriple().empty()) { |
| M->setTargetTriple(DefaultTriple); |
| } |
| |
| // For ThinLTO we want to propagate the source file name to ensure |
| // we can create the correct global identifiers matching those in the |
| // original module. |
| if (SetName) |
| L.getModule().setSourceFileName(M->getSourceFileName()); |
| |
| if (Error E = L.move(std::move(M), Keep, |
| [](GlobalValue &, IRMover::ValueAdder) {})) { |
| handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EIB) { |
| message(LDPL_FATAL, "Failed to link module %s: %s", Name.str().c_str(), |
| EIB.message().c_str()); |
| }); |
| } |
| |
| for (const auto &I : Realign) { |
| GlobalValue *Dst = L.getModule().getNamedValue(I.first()); |
| if (!Dst) |
| continue; |
| cast<GlobalVariable>(Dst)->setAlignment(I.second); |
| } |
| } |
| |
| /// Perform the ThinLTO backend on a single module, invoking the LTO and codegen |
| /// pipelines. |
| static void thinLTOBackendTask(claimed_file &F, const void *View, |
| StringRef Name, raw_fd_ostream *ApiFile, |
| const ModuleSummaryIndex &CombinedIndex, |
| raw_fd_ostream *OS, unsigned TaskID, |
| StringMap<MemoryBufferRef> &ModuleMap, |
| FunctionImporter::ImportMapTy &ImportList, |
| std::map<GlobalValue::GUID, GlobalValueSummary *> &DefinedGlobals) { |
| // Need to use a separate context for each task |
| LLVMContext Context; |
| Context.setDiscardValueNames(options::TheOutputType != |
| options::OT_SAVE_TEMPS); |
| Context.enableDebugTypeODRUniquing(); // Merge debug info types. |
| Context.setDiagnosticHandler(diagnosticHandlerForContext, nullptr, true); |
| |
| std::unique_ptr<llvm::Module> NewModule(new llvm::Module(Name, Context)); |
| IRMover L(*NewModule.get()); |
| |
| StringSet<> Dummy; |
| linkInModule(Context, L, F, View, Name, ApiFile, Dummy, true); |
| if (renameModuleForThinLTO(*NewModule, CombinedIndex)) |
| message(LDPL_FATAL, "Failed to rename module for ThinLTO"); |
| |
| CodeGen codeGen(std::move(NewModule), OS, TaskID, &CombinedIndex, Name, |
| &ModuleMap, &ImportList, &DefinedGlobals); |
| codeGen.runAll(); |
| } |
| |
| /// Launch each module's backend pipeline in a separate task in a thread pool. |
| static void |
| thinLTOBackends(raw_fd_ostream *ApiFile, |
| const ModuleSummaryIndex &CombinedIndex, |
| StringMap<MemoryBufferRef> &ModuleMap, |
| StringMap<FunctionImporter::ImportMapTy> &ImportLists, |
| StringMap<std::map<GlobalValue::GUID, GlobalValueSummary *>> |
| &ModuleToDefinedGVSummaries) { |
| unsigned TaskCount = 0; |
| std::vector<ThinLTOTaskInfo> Tasks; |
| Tasks.reserve(Modules.size()); |
| unsigned int MaxThreads = options::Parallelism |
| ? options::Parallelism |
| : thread::hardware_concurrency(); |
| |
| // Create ThreadPool in nested scope so that threads will be joined |
| // on destruction. |
| { |
| ThreadPool ThinLTOThreadPool(MaxThreads); |
| for (claimed_file &F : Modules) { |
| // Do all the gold callbacks in the main thread, since gold is not thread |
| // safe by default. |
| const void *View = getSymbolsAndView(F); |
| if (!View) |
| continue; |
| |
| SmallString<128> Filename; |
| if (!options::obj_path.empty()) |
| // Note that openOutputFile will append a unique ID for each task |
| Filename = options::obj_path; |
| else if (options::TheOutputType == options::OT_SAVE_TEMPS) { |
| // Use the input file name so that we get a unique and identifiable |
| // output file for each ThinLTO backend task. |
| Filename = F.name; |
| Filename += ".thinlto.o"; |
| } |
| bool TempOutFile = Filename.empty(); |
| |
| SmallString<128> NewFilename; |
| int FD = openOutputFile(Filename, TempOutFile, NewFilename, |
| // Only append the TaskID if we will use the |
| // non-unique obj_path. |
| !options::obj_path.empty() ? TaskCount : -1); |
| TaskCount++; |
| std::unique_ptr<raw_fd_ostream> OS = |
| llvm::make_unique<raw_fd_ostream>(FD, true); |
| |
| // Enqueue the task |
| ThinLTOThreadPool.async(thinLTOBackendTask, std::ref(F), View, F.name, |
| ApiFile, std::ref(CombinedIndex), OS.get(), |
| TaskCount, std::ref(ModuleMap), |
| std::ref(ImportLists[F.name]), |
| std::ref(ModuleToDefinedGVSummaries[F.name])); |
| |
| // Record the information needed by the task or during its cleanup |
| // to a ThinLTOTaskInfo instance. For information needed by the task |
| // the unique_ptr ownership is transferred to the ThinLTOTaskInfo. |
| Tasks.emplace_back(std::move(OS), NewFilename.c_str(), TempOutFile); |
| } |
| } |
| |
| for (auto &Task : Tasks) |
| Task.cleanup(); |
| } |
| |
| /// Parse the thinlto_prefix_replace option into the \p OldPrefix and |
| /// \p NewPrefix strings, if it was specified. |
| static void getThinLTOOldAndNewPrefix(std::string &OldPrefix, |
| std::string &NewPrefix) { |
| StringRef PrefixReplace = options::thinlto_prefix_replace; |
| assert(PrefixReplace.empty() || PrefixReplace.find(";") != StringRef::npos); |
| std::pair<StringRef, StringRef> Split = PrefixReplace.split(";"); |
| OldPrefix = Split.first.str(); |
| NewPrefix = Split.second.str(); |
| } |
| |
| /// Given the original \p Path to an output file, replace any path |
| /// prefix matching \p OldPrefix with \p NewPrefix. Also, create the |
| /// resulting directory if it does not yet exist. |
| static std::string getThinLTOOutputFile(const std::string &Path, |
| const std::string &OldPrefix, |
| const std::string &NewPrefix) { |
| if (OldPrefix.empty() && NewPrefix.empty()) |
| return Path; |
| SmallString<128> NewPath(Path); |
| llvm::sys::path::replace_path_prefix(NewPath, OldPrefix, NewPrefix); |
| StringRef ParentPath = llvm::sys::path::parent_path(NewPath.str()); |
| if (!ParentPath.empty()) { |
| // Make sure the new directory exists, creating it if necessary. |
| if (std::error_code EC = llvm::sys::fs::create_directories(ParentPath)) |
| llvm::errs() << "warning: could not create directory '" << ParentPath |
| << "': " << EC.message() << '\n'; |
| } |
| return NewPath.str(); |
| } |
| |
| /// Perform ThinLTO link, which creates the combined index file. |
| /// Also, either launch backend threads or (under thinlto-index-only) |
| /// emit individual index files for distributed backends and exit. |
| static ld_plugin_status thinLTOLink(raw_fd_ostream *ApiFile) { |
| // Map from a module name to the corresponding buffer holding a view of the |
| // bitcode provided via the get_view gold callback. |
| StringMap<MemoryBufferRef> ModuleMap; |
| // Map to own RAII objects that manage the file opening and releasing |
| // interfaces with gold. |
| DenseMap<void *, std::unique_ptr<PluginInputFile>> HandleToInputFile; |
| |
| // Keep track of symbols that must not be internalized because they |
| // are referenced outside of a single IR module. |
| DenseSet<GlobalValue::GUID> Preserve; |
| |
| // Keep track of the prevailing copy for each GUID, for use in resolving |
| // weak linkages. |
| DenseMap<GlobalValue::GUID, const GlobalValueSummary *> PrevailingCopy; |
| |
| ModuleSummaryIndex CombinedIndex; |
| uint64_t NextModuleId = 0; |
| for (claimed_file &F : Modules) { |
| if (!HandleToInputFile.count(F.leader_handle)) |
| HandleToInputFile.insert(std::make_pair( |
| F.leader_handle, llvm::make_unique<PluginInputFile>(F.handle))); |
| // Pass this into getModuleSummaryIndexForFile |
| const void *View = getSymbolsAndView(F); |
| if (!View) |
| continue; |
| |
| MemoryBufferRef ModuleBuffer(StringRef((const char *)View, F.filesize), |
| F.name); |
| assert(ModuleMap.find(ModuleBuffer.getBufferIdentifier()) == |
| ModuleMap.end() && |
| "Expect unique Buffer Identifier"); |
| ModuleMap[ModuleBuffer.getBufferIdentifier()] = ModuleBuffer; |
| |
| std::unique_ptr<ModuleSummaryIndex> Index = getModuleSummaryIndexForFile(F); |
| |
| // Use gold's symbol resolution information to identify symbols referenced |
| // by more than a single IR module (i.e. referenced by multiple IR modules |
| // or by a non-IR module). Cross references introduced by importing are |
| // checked separately via the export lists. Also track the prevailing copy |
| // for later symbol resolution. |
| for (auto &Sym : F.syms) { |
| ld_plugin_symbol_resolution Resolution = |
| (ld_plugin_symbol_resolution)Sym.resolution; |
| GlobalValue::GUID SymGUID = GlobalValue::getGUID(Sym.name); |
| if (Resolution != LDPR_PREVAILING_DEF_IRONLY) |
| Preserve.insert(SymGUID); |
| |
| if (Index && (Resolution == LDPR_PREVAILING_DEF || |
| Resolution == LDPR_PREVAILING_DEF_IRONLY || |
| Resolution == LDPR_PREVAILING_DEF_IRONLY_EXP)) |
| PrevailingCopy[SymGUID] = Index->getGlobalValueSummary(SymGUID); |
| } |
| |
| // Skip files without a module summary. |
| if (Index) |
| CombinedIndex.mergeFrom(std::move(Index), ++NextModuleId); |
| } |
| |
| // Collect for each module the list of function it defines (GUID -> |
| // Summary). |
| StringMap<std::map<GlobalValue::GUID, GlobalValueSummary *>> |
| ModuleToDefinedGVSummaries(NextModuleId); |
| CombinedIndex.collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries); |
| |
| StringMap<FunctionImporter::ImportMapTy> ImportLists(NextModuleId); |
| StringMap<FunctionImporter::ExportSetTy> ExportLists(NextModuleId); |
| ComputeCrossModuleImport(CombinedIndex, ModuleToDefinedGVSummaries, |
| ImportLists, ExportLists); |
| |
| auto isPrevailing = [&](GlobalValue::GUID GUID, const GlobalValueSummary *S) { |
| const auto &Prevailing = PrevailingCopy.find(GUID); |
| assert(Prevailing != PrevailingCopy.end()); |
| return Prevailing->second == S; |
| }; |
| |
| // Callback for internalization, to prevent internalization of symbols |
| // that were not candidates initially, and those that are being imported |
| // (which introduces new cross references). |
| auto isExported = [&](StringRef ModuleIdentifier, GlobalValue::GUID GUID) { |
| const auto &ExportList = ExportLists.find(ModuleIdentifier); |
| return (ExportList != ExportLists.end() && |
| ExportList->second.count(GUID)) || |
| Preserve.count(GUID); |
| }; |
| |
| thinLTOResolveWeakForLinkerInIndex( |
| CombinedIndex, isPrevailing, |
| [](StringRef ModuleIdentifier, GlobalValue::GUID GUID, |
| GlobalValue::LinkageTypes NewLinkage) {}); |
| |
| // Use global summary-based analysis to identify symbols that can be |
| // internalized (because they aren't exported or preserved as per callback). |
| // Changes are made in the index, consumed in the ThinLTO backends. |
| thinLTOInternalizeAndPromoteInIndex(CombinedIndex, isExported); |
| |
| if (options::thinlto_emit_imports_files && !options::thinlto_index_only) |
| message(LDPL_WARNING, |
| "thinlto-emit-imports-files ignored unless thinlto-index-only"); |
| |
| if (options::thinlto_index_only) { |
| // If the thinlto-prefix-replace option was specified, parse it and |
| // extract the old and new prefixes. |
| std::string OldPrefix, NewPrefix; |
| getThinLTOOldAndNewPrefix(OldPrefix, NewPrefix); |
| |
| // For each input bitcode file, generate an individual index that |
| // contains summaries only for its own global values, and for any that |
| // should be imported. |
| for (claimed_file &F : Modules) { |
| std::error_code EC; |
| |
| std::string NewModulePath = |
| getThinLTOOutputFile(F.name, OldPrefix, NewPrefix); |
| raw_fd_ostream OS((Twine(NewModulePath) + ".thinlto.bc").str(), EC, |
| sys::fs::OpenFlags::F_None); |
| if (EC) |
| message(LDPL_FATAL, "Unable to open %s.thinlto.bc for writing: %s", |
| NewModulePath.c_str(), EC.message().c_str()); |
| // Build a map of module to the GUIDs and summary objects that should |
| // be written to its index. |
| std::map<std::string, GVSummaryMapTy> ModuleToSummariesForIndex; |
| gatherImportedSummariesForModule(F.name, ModuleToDefinedGVSummaries, |
| ImportLists, ModuleToSummariesForIndex); |
| WriteIndexToFile(CombinedIndex, OS, &ModuleToSummariesForIndex); |
| |
| if (options::thinlto_emit_imports_files) { |
| if ((EC = EmitImportsFiles(F.name, |
| (Twine(NewModulePath) + ".imports").str(), |
| ImportLists))) |
| message(LDPL_FATAL, "Unable to open %s.imports", |
| NewModulePath.c_str(), EC.message().c_str()); |
| } |
| } |
| |
| cleanup_hook(); |
| exit(0); |
| } |
| |
| // Create OS in nested scope so that it will be closed on destruction. |
| { |
| std::error_code EC; |
| raw_fd_ostream OS(output_name + ".thinlto.bc", EC, |
| sys::fs::OpenFlags::F_None); |
| if (EC) |
| message(LDPL_FATAL, "Unable to open %s.thinlto.bc for writing: %s", |
| output_name.data(), EC.message().c_str()); |
| WriteIndexToFile(CombinedIndex, OS); |
| } |
| |
| thinLTOBackends(ApiFile, CombinedIndex, ModuleMap, ImportLists, |
| ModuleToDefinedGVSummaries); |
| return LDPS_OK; |
| } |
| |
| /// gold informs us that all symbols have been read. At this point, we use |
| /// get_symbols to see if any of our definitions have been overridden by a |
| /// native object file. Then, perform optimization and codegen. |
| static ld_plugin_status allSymbolsReadHook(raw_fd_ostream *ApiFile) { |
| if (Modules.empty()) |
| return LDPS_OK; |
| |
| if (unsigned NumOpts = options::extra.size()) |
| cl::ParseCommandLineOptions(NumOpts, &options::extra[0]); |
| |
| if (options::thinlto) |
| return thinLTOLink(ApiFile); |
| |
| LLVMContext Context; |
| Context.setDiscardValueNames(options::TheOutputType != |
| options::OT_SAVE_TEMPS); |
| Context.enableDebugTypeODRUniquing(); // Merge debug info types. |
| Context.setDiagnosticHandler(diagnosticHandlerForContext, nullptr, true); |
| |
| std::unique_ptr<Module> Combined(new Module("ld-temp.o", Context)); |
| IRMover L(*Combined); |
| |
| StringSet<> Internalize; |
| for (claimed_file &F : Modules) { |
| // RAII object to manage the file opening and releasing interfaces with |
| // gold. |
| PluginInputFile InputFile(F.handle); |
| const void *View = getSymbolsAndView(F); |
| if (!View) |
| continue; |
| linkInModule(Context, L, F, View, F.name, ApiFile, Internalize); |
| } |
| |
| for (const auto &Name : Internalize) { |
| GlobalValue *GV = Combined->getNamedValue(Name.first()); |
| if (GV) |
| internalize(*GV); |
| } |
| |
| if (options::TheOutputType == options::OT_DISABLE) |
| return LDPS_OK; |
| |
| if (options::TheOutputType != options::OT_NORMAL) { |
| std::string path; |
| if (options::TheOutputType == options::OT_BC_ONLY) |
| path = output_name; |
| else |
| path = output_name + ".bc"; |
| saveBCFile(path, *Combined); |
| if (options::TheOutputType == options::OT_BC_ONLY) |
| return LDPS_OK; |
| } |
| |
| CodeGen codeGen(std::move(Combined)); |
| codeGen.runAll(); |
| |
| if (!options::extra_library_path.empty() && |
| set_extra_library_path(options::extra_library_path.c_str()) != LDPS_OK) |
| message(LDPL_FATAL, "Unable to set the extra library path."); |
| |
| return LDPS_OK; |
| } |
| |
| static ld_plugin_status all_symbols_read_hook(void) { |
| ld_plugin_status Ret; |
| if (!options::generate_api_file) { |
| Ret = allSymbolsReadHook(nullptr); |
| } else { |
| std::error_code EC; |
| raw_fd_ostream ApiFile("apifile.txt", EC, sys::fs::F_None); |
| if (EC) |
| message(LDPL_FATAL, "Unable to open apifile.txt for writing: %s", |
| EC.message().c_str()); |
| Ret = allSymbolsReadHook(&ApiFile); |
| } |
| |
| llvm_shutdown(); |
| |
| if (options::TheOutputType == options::OT_BC_ONLY || |
| options::TheOutputType == options::OT_DISABLE) { |
| if (options::TheOutputType == options::OT_DISABLE) { |
| // Remove the output file here since ld.bfd creates the output file |
| // early. |
| std::error_code EC = sys::fs::remove(output_name); |
| if (EC) |
| message(LDPL_ERROR, "Failed to delete '%s': %s", output_name.c_str(), |
| EC.message().c_str()); |
| } |
| exit(0); |
| } |
| |
| return Ret; |
| } |
| |
| static ld_plugin_status cleanup_hook(void) { |
| for (std::string &Name : Cleanup) { |
| std::error_code EC = sys::fs::remove(Name); |
| if (EC) |
| message(LDPL_ERROR, "Failed to delete '%s': %s", Name.c_str(), |
| EC.message().c_str()); |
| } |
| |
| return LDPS_OK; |
| } |