| //===-- 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/Config/config.h" // plugin-api.h requires HAVE_STDINT_H |
| #include "llvm/ADT/DenseSet.h" |
| #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/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/Linker/IRMover.h" |
| #include "llvm/MC/SubtargetFeature.h" |
| #include "llvm/Object/FunctionIndexObjectFile.h" |
| #include "llvm/Object/IRObjectFile.h" |
| #include "llvm/Support/Host.h" |
| #include "llvm/Support/ManagedStatic.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Support/TargetRegistry.h" |
| #include "llvm/Support/TargetSelect.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/Transforms/IPO.h" |
| #include "llvm/Transforms/IPO/PassManagerBuilder.h" |
| #include "llvm/Transforms/Utils/GlobalStatus.h" |
| #include "llvm/Transforms/Utils/ModuleUtils.h" |
| #include "llvm/Transforms/Utils/ValueMapper.h" |
| #include <list> |
| #include <plugin-api.h> |
| #include <system_error> |
| #include <vector> |
| |
| #ifndef LDPO_PIE |
| // FIXME: remove this declaration when we stop maintaining Ubuntu Quantal and |
| // Precise and Debian Wheezy (binutils 2.23 is required) |
| # define LDPO_PIE 3 |
| #endif |
| |
| 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; |
| std::vector<ld_plugin_symbol> syms; |
| }; |
| |
| /// RAII wrapper to manage opening and releasing of a ld_plugin_input_file. |
| struct PluginInputFile { |
| void *Handle; |
| ld_plugin_input_file File; |
| |
| PluginInputFile(void *Handle) : Handle(Handle) { |
| if (get_input_file(Handle, &File) != LDPS_OK) |
| message(LDPL_FATAL, "Failed to get file information"); |
| } |
| ~PluginInputFile() { |
| if (release_input_file(Handle) != LDPS_OK) |
| message(LDPL_FATAL, "Failed to release file information"); |
| } |
| ld_plugin_input_file &file() { return File; } |
| }; |
| |
| struct ResolutionInfo { |
| bool IsLinkonceOdr = true; |
| bool UnnamedAddr = true; |
| GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility; |
| bool CommonInternal = false; |
| bool UseCommon = false; |
| unsigned CommonSize = 0; |
| unsigned CommonAlign = 0; |
| claimed_file *CommonFile = nullptr; |
| }; |
| } |
| |
| 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 Reloc::Model RelocationModel = Reloc::Default; |
| static std::string output_name = ""; |
| static std::list<claimed_file> Modules; |
| static StringMap<ResolutionInfo> ResInfo; |
| static std::vector<std::string> Cleanup; |
| static llvm::TargetOptions TargetOpts; |
| |
| 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; |
| static unsigned Parallelism = 1; |
| #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; |
| // 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.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) { |
| switch (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: |
| 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, "relesase_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()); |
| llvm_unreachable("Fatal doesn't return."); |
| 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; |
| |
| // If we are doing ThinLTO compilation, don't need to process the symbols. |
| // Later we simply build a combined index file after all files are claimed. |
| if (options::thinlto) |
| return LDPS_OK; |
| |
| 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 &= GV->hasUnnamedAddr(); |
| Res.IsLinkonceOdr &= GV->hasLinkOnceLinkage(); |
| if (GV->hasCommonLinkage()) { |
| Res.CommonAlign = std::max(Res.CommonAlign, GV->getAlignment()); |
| const DataLayout &DL = GV->getParent()->getDataLayout(); |
| uint64_t Size = DL.getTypeAllocSize(GV->getType()->getElementType()); |
| if (Size >= Res.CommonSize) { |
| Res.CommonSize = Size; |
| Res.CommonFile = &cf; |
| } |
| } |
| Res.Visibility = getMinVisibility(Res.Visibility, GV->getVisibility()); |
| switch (GV->getVisibility()) { |
| case GlobalValue::DefaultVisibility: |
| sym.visibility = LDPV_DEFAULT; |
| 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; |
| } |
| |
| static std::unique_ptr<FunctionInfoIndex> |
| getFunctionIndexForFile(claimed_file &F, ld_plugin_input_file &Info) { |
| |
| if (get_symbols(F.handle, F.syms.size(), &F.syms[0]) != 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"); |
| |
| MemoryBufferRef BufferRef(StringRef((const char *)View, Info.filesize), |
| Info.name); |
| |
| // Don't bother trying to build an index if there is no summary information |
| // in this bitcode file. |
| if (!object::FunctionIndexObjectFile::hasFunctionSummaryInMemBuffer( |
| BufferRef, diagnosticHandler)) |
| return std::unique_ptr<FunctionInfoIndex>(nullptr); |
| |
| ErrorOr<std::unique_ptr<object::FunctionIndexObjectFile>> ObjOrErr = |
| object::FunctionIndexObjectFile::create(BufferRef, diagnosticHandler); |
| |
| if (std::error_code EC = ObjOrErr.getError()) |
| message(LDPL_FATAL, "Could not read function index bitcode from file : %s", |
| EC.message().c_str()); |
| |
| object::FunctionIndexObjectFile &Obj = **ObjOrErr; |
| |
| return Obj.takeIndex(); |
| } |
| |
| static std::unique_ptr<Module> |
| getModuleForFile(LLVMContext &Context, claimed_file &F, |
| ld_plugin_input_file &Info, raw_fd_ostream *ApiFile, |
| StringSet<> &Internalize, StringSet<> &Maybe, |
| std::vector<GlobalValue *> &Keep) { |
| |
| if (get_symbols(F.handle, F.syms.size(), F.syms.data()) != 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"); |
| |
| MemoryBufferRef BufferRef(StringRef((const char *)View, Info.filesize), |
| Info.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()) { |
| cast<GlobalVariable>(GV)->setAlignment(Res.CommonAlign); |
| if (Resolution == LDPR_PREVAILING_DEF_IRONLY) |
| Res.CommonInternal = true; |
| |
| if (Resolution == LDPR_PREVAILING_DEF_IRONLY || |
| Resolution == LDPR_PREVAILING_DEF) |
| Res.UseCommon = true; |
| |
| if (Res.CommonFile == &F && Res.UseCommon) { |
| if (Res.CommonInternal) |
| Resolution = LDPR_PREVAILING_DEF_IRONLY; |
| else |
| Resolution = LDPR_PREVAILING_DEF; |
| } else { |
| Resolution = LDPR_PREEMPTED_IR; |
| } |
| } |
| |
| 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: { |
| // We can only check for address uses after we merge the modules. The |
| // reason is that this GV might have a copy in another module |
| // and in that module the address might be significant, but that |
| // copy will be LDPR_PREEMPTED_IR. |
| Maybe.insert(GV->getName()); |
| Keep.push_back(GV); |
| break; |
| } |
| } |
| |
| freeSymName(Sym); |
| } |
| |
| return Obj.takeModule(); |
| } |
| |
| static void runLTOPasses(Module &M, TargetMachine &TM) { |
| M.setDataLayout(TM.createDataLayout()); |
| |
| 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; |
| PMB.populateLTOPassManager(passes); |
| passes.run(M); |
| } |
| |
| 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 codegen(std::unique_ptr<Module> M) { |
| const std::string &TripleStr = M->getTargetTriple(); |
| Triple TheTriple(TripleStr); |
| |
| std::string ErrMsg; |
| const Target *TheTarget = TargetRegistry::lookupTarget(TripleStr, ErrMsg); |
| if (!TheTarget) |
| message(LDPL_FATAL, "Target not found: %s", ErrMsg.c_str()); |
| |
| if (unsigned NumOpts = options::extra.size()) |
| cl::ParseCommandLineOptions(NumOpts, &options::extra[0]); |
| |
| SubtargetFeatures Features; |
| Features.getDefaultSubtargetFeatures(TheTriple); |
| for (const std::string &A : MAttrs) |
| Features.AddFeature(A); |
| |
| TargetOptions Options = InitTargetOptionsFromCodeGenFlags(); |
| CodeGenOpt::Level CGOptLevel; |
| switch (options::OptLevel) { |
| case 0: |
| CGOptLevel = CodeGenOpt::None; |
| break; |
| case 1: |
| CGOptLevel = CodeGenOpt::Less; |
| break; |
| case 2: |
| CGOptLevel = CodeGenOpt::Default; |
| break; |
| case 3: |
| CGOptLevel = CodeGenOpt::Aggressive; |
| break; |
| } |
| std::unique_ptr<TargetMachine> TM(TheTarget->createTargetMachine( |
| TripleStr, options::mcpu, Features.getString(), Options, RelocationModel, |
| CodeModel::Default, CGOptLevel)); |
| |
| runLTOPasses(*M, *TM); |
| |
| if (options::TheOutputType == options::OT_SAVE_TEMPS) |
| saveBCFile(output_name + ".opt.bc", *M); |
| |
| SmallString<128> Filename; |
| if (!options::obj_path.empty()) |
| Filename = options::obj_path; |
| else if (options::TheOutputType == options::OT_SAVE_TEMPS) |
| Filename = output_name + ".o"; |
| |
| std::vector<SmallString<128>> Filenames(options::Parallelism); |
| bool TempOutFile = Filename.empty(); |
| { |
| // Open a file descriptor for each backend thread. 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(options::Parallelism); |
| for (unsigned I = 0; I != options::Parallelism; ++I) { |
| int FD; |
| if (TempOutFile) { |
| std::error_code EC = |
| sys::fs::createTemporaryFile("lto-llvm", "o", FD, Filenames[I]); |
| if (EC) |
| message(LDPL_FATAL, "Could not create temporary file: %s", |
| EC.message().c_str()); |
| } else { |
| Filenames[I] = Filename; |
| if (options::Parallelism != 1) |
| Filenames[I] += utostr(I); |
| std::error_code EC = |
| sys::fs::openFileForWrite(Filenames[I], FD, sys::fs::F_None); |
| if (EC) |
| message(LDPL_FATAL, "Could not open file: %s", EC.message().c_str()); |
| } |
| OSs.emplace_back(FD, true); |
| OSPtrs[I] = &OSs.back(); |
| } |
| |
| // Run backend threads. |
| splitCodeGen(std::move(M), OSPtrs, options::mcpu, Features.getString(), |
| Options, RelocationModel, CodeModel::Default, CGOptLevel); |
| } |
| |
| for (auto &Filename : Filenames) { |
| 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()); |
| } |
| } |
| |
| /// 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 we are doing ThinLTO compilation, simply build the combined |
| // function index/summary and emit it. We don't need to parse the modules |
| // and link them in this case. |
| if (options::thinlto) { |
| FunctionInfoIndex CombinedIndex; |
| uint64_t NextModuleId = 0; |
| for (claimed_file &F : Modules) { |
| PluginInputFile InputFile(F.handle); |
| |
| std::unique_ptr<FunctionInfoIndex> Index = |
| getFunctionIndexForFile(F, InputFile.file()); |
| |
| // Skip files without a function summary. |
| if (Index) |
| CombinedIndex.mergeFrom(std::move(Index), ++NextModuleId); |
| } |
| |
| 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()); |
| WriteFunctionSummaryToFile(CombinedIndex, OS); |
| OS.close(); |
| |
| cleanup_hook(); |
| exit(0); |
| } |
| |
| LLVMContext Context; |
| Context.setDiagnosticHandler(diagnosticHandlerForContext, nullptr, true); |
| |
| std::unique_ptr<Module> Combined(new Module("ld-temp.o", Context)); |
| IRMover L(*Combined); |
| |
| std::string DefaultTriple = sys::getDefaultTargetTriple(); |
| |
| StringSet<> Internalize; |
| StringSet<> Maybe; |
| for (claimed_file &F : Modules) { |
| PluginInputFile InputFile(F.handle); |
| std::vector<GlobalValue *> Keep; |
| std::unique_ptr<Module> M = getModuleForFile( |
| Context, F, InputFile.file(), ApiFile, Internalize, Maybe, Keep); |
| if (!options::triple.empty()) |
| M->setTargetTriple(options::triple.c_str()); |
| else if (M->getTargetTriple().empty()) |
| M->setTargetTriple(DefaultTriple); |
| |
| if (L.move(*M, Keep, [](GlobalValue &, IRMover::ValueAdder) {})) |
| message(LDPL_FATAL, "Failed to link module"); |
| } |
| |
| for (const auto &Name : Internalize) { |
| GlobalValue *GV = Combined->getNamedValue(Name.first()); |
| if (GV) |
| internalize(*GV); |
| } |
| |
| for (const auto &Name : Maybe) { |
| GlobalValue *GV = Combined->getNamedValue(Name.first()); |
| if (!GV) |
| continue; |
| GV->setLinkage(GlobalValue::LinkOnceODRLinkage); |
| if (canBeOmittedFromSymbolTable(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(std::move(Combined)); |
| |
| 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. |
| sys::fs::remove(output_name); |
| 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; |
| } |