| //===-- 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/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/Linker.h" |
| #include "llvm/MC/SubtargetFeature.h" |
| #include "llvm/Object/IRObjectFile.h" |
| #include "llvm/Support/raw_ostream.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/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; |
| |
| namespace { |
| struct claimed_file { |
| void *handle; |
| std::vector<ld_plugin_symbol> syms; |
| }; |
| } |
| |
| 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_get_input_file get_input_file = nullptr; |
| static ld_plugin_release_input_file release_input_file = 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 ld_plugin_message message = discard_message; |
| static Reloc::Model RelocationModel = Reloc::Default; |
| static std::string output_name = ""; |
| static std::list<claimed_file> Modules; |
| 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 std::string obj_path; |
| static std::string extra_library_path; |
| static std::string triple; |
| static std::string mcpu; |
| // 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.size() == 2 && opt[0] == 'O') { |
| if (opt[1] < '0' || opt[1] > '3') |
| report_fatal_error("Optimization level must be between 0 and 3"); |
| OptLevel = opt[1] - '0'; |
| } 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, void *Context) { |
| 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()); |
| } |
| |
| /// 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(diagnosticHandler); |
| 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; |
| |
| 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()); |
| |
| sym.visibility = LDPV_DEFAULT; |
| if (GV) { |
| 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()); |
| else if (Base->hasWeakLinkage() || Base->hasLinkOnceLinkage()) |
| sym.comdat_key = strdup(sym.name); |
| } |
| |
| sym.resolution = LDPR_UNKNOWN; |
| } |
| |
| if (!cf.syms.empty()) { |
| if (add_symbols(cf.handle, cf.syms.size(), &cf.syms[0]) != LDPS_OK) { |
| message(LDPL_ERROR, "Unable to add symbols!"); |
| return LDPS_ERR; |
| } |
| } |
| |
| return LDPS_OK; |
| } |
| |
| static void keepGlobalValue(GlobalValue &GV, |
| std::vector<GlobalAlias *> &KeptAliases) { |
| assert(!GV.hasLocalLinkage()); |
| |
| if (auto *GA = dyn_cast<GlobalAlias>(&GV)) |
| KeptAliases.push_back(GA); |
| |
| switch (GV.getLinkage()) { |
| default: |
| break; |
| case GlobalValue::LinkOnceAnyLinkage: |
| GV.setLinkage(GlobalValue::WeakAnyLinkage); |
| break; |
| case GlobalValue::LinkOnceODRLinkage: |
| GV.setLinkage(GlobalValue::WeakODRLinkage); |
| break; |
| } |
| |
| assert(!GV.isDiscardableIfUnused()); |
| } |
| |
| 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 void drop(GlobalValue &GV) { |
| if (auto *F = dyn_cast<Function>(&GV)) { |
| F->deleteBody(); |
| F->setComdat(nullptr); // Should deleteBody do this? |
| return; |
| } |
| |
| if (auto *Var = dyn_cast<GlobalVariable>(&GV)) { |
| Var->setInitializer(nullptr); |
| Var->setLinkage( |
| GlobalValue::ExternalLinkage); // Should setInitializer do this? |
| Var->setComdat(nullptr); // and this? |
| return; |
| } |
| |
| auto &Alias = cast<GlobalAlias>(GV); |
| Module &M = *Alias.getParent(); |
| PointerType &Ty = *cast<PointerType>(Alias.getType()); |
| GlobalValue::LinkageTypes L = Alias.getLinkage(); |
| auto *Var = |
| new GlobalVariable(M, Ty.getElementType(), /*isConstant*/ false, L, |
| /*Initializer*/ nullptr); |
| Var->takeName(&Alias); |
| Alias.replaceAllUsesWith(Var); |
| Alias.eraseFromParent(); |
| } |
| |
| 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"); |
| } |
| |
| namespace { |
| class LocalValueMaterializer : public ValueMaterializer { |
| DenseSet<GlobalValue *> &Dropped; |
| DenseMap<GlobalObject *, GlobalObject *> LocalVersions; |
| |
| public: |
| LocalValueMaterializer(DenseSet<GlobalValue *> &Dropped) : Dropped(Dropped) {} |
| Value *materializeValueFor(Value *V) override; |
| }; |
| } |
| |
| Value *LocalValueMaterializer::materializeValueFor(Value *V) { |
| auto *GO = dyn_cast<GlobalObject>(V); |
| if (!GO) |
| return nullptr; |
| |
| auto I = LocalVersions.find(GO); |
| if (I != LocalVersions.end()) |
| return I->second; |
| |
| if (!Dropped.count(GO)) |
| return nullptr; |
| |
| Module &M = *GO->getParent(); |
| GlobalValue::LinkageTypes L = GO->getLinkage(); |
| GlobalObject *Declaration; |
| if (auto *F = dyn_cast<Function>(GO)) { |
| Declaration = Function::Create(F->getFunctionType(), L, "", &M); |
| } else { |
| auto *Var = cast<GlobalVariable>(GO); |
| Declaration = new GlobalVariable(M, Var->getType()->getElementType(), |
| Var->isConstant(), L, |
| /*Initializer*/ nullptr); |
| } |
| Declaration->takeName(GO); |
| Declaration->copyAttributesFrom(GO); |
| |
| GO->setLinkage(GlobalValue::InternalLinkage); |
| GO->setName(Declaration->getName()); |
| Dropped.erase(GO); |
| GO->replaceAllUsesWith(Declaration); |
| |
| LocalVersions[Declaration] = GO; |
| |
| return GO; |
| } |
| |
| static Constant *mapConstantToLocalCopy(Constant *C, ValueToValueMapTy &VM, |
| LocalValueMaterializer *Materializer) { |
| return MapValue(C, VM, RF_IgnoreMissingEntries, nullptr, Materializer); |
| } |
| |
| 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<Module> |
| getModuleForFile(LLVMContext &Context, claimed_file &F, |
| ld_plugin_input_file &Info, raw_fd_ostream *ApiFile, |
| StringSet<> &Internalize, StringSet<> &Maybe) { |
| |
| 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); |
| 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); |
| |
| DenseSet<GlobalValue *> Drop; |
| std::vector<GlobalAlias *> KeptAliases; |
| |
| unsigned SymNum = 0; |
| for (auto &ObjSym : Obj.symbols()) { |
| 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'; |
| |
| GlobalValue *GV = Obj.getSymbolGV(ObjSym.getRawDataRefImpl()); |
| if (!GV) { |
| freeSymName(Sym); |
| continue; // Asm symbol. |
| } |
| |
| if (Resolution != LDPR_PREVAILING_DEF_IRONLY && GV->hasCommonLinkage()) { |
| // Common linkage is special. There is no single symbol that wins the |
| // resolution. Instead we have to collect the maximum alignment and size. |
| // The IR linker does that for us if we just pass it every common GV. |
| // We still have to keep track of LDPR_PREVAILING_DEF_IRONLY so we |
| // internalize once the IR linker has done its job. |
| freeSymName(Sym); |
| continue; |
| } |
| |
| switch (Resolution) { |
| case LDPR_UNKNOWN: |
| llvm_unreachable("Unexpected resolution"); |
| |
| case LDPR_RESOLVED_IR: |
| case LDPR_RESOLVED_EXEC: |
| case LDPR_RESOLVED_DYN: |
| assert(GV->isDeclarationForLinker()); |
| break; |
| |
| case LDPR_UNDEF: |
| if (!GV->isDeclarationForLinker()) { |
| assert(GV->hasComdat()); |
| Drop.insert(GV); |
| } |
| break; |
| |
| case LDPR_PREVAILING_DEF_IRONLY: { |
| keepGlobalValue(*GV, KeptAliases); |
| if (!Used.count(GV)) { |
| // Since we use the regular lib/Linker, we cannot just internalize GV |
| // now or it will not be copied to the merged module. Instead we force |
| // it to be copied and then internalize it. |
| Internalize.insert(GV->getName()); |
| } |
| break; |
| } |
| |
| case LDPR_PREVAILING_DEF: |
| keepGlobalValue(*GV, KeptAliases); |
| break; |
| |
| case LDPR_PREEMPTED_IR: |
| // Gold might have selected a linkonce_odr and preempted a weak_odr. |
| // In that case we have to make sure we don't end up internalizing it. |
| if (!GV->isDiscardableIfUnused()) |
| Maybe.erase(GV->getName()); |
| |
| // fall-through |
| case LDPR_PREEMPTED_REG: |
| Drop.insert(GV); |
| 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. |
| if (GV->hasLinkOnceODRLinkage()) |
| Maybe.insert(GV->getName()); |
| keepGlobalValue(*GV, KeptAliases); |
| break; |
| } |
| } |
| |
| freeSymName(Sym); |
| } |
| |
| ValueToValueMapTy VM; |
| LocalValueMaterializer Materializer(Drop); |
| for (GlobalAlias *GA : KeptAliases) { |
| // Gold told us to keep GA. It is possible that a GV usied in the aliasee |
| // expression is being dropped. If that is the case, that GV must be copied. |
| Constant *Aliasee = GA->getAliasee(); |
| Constant *Replacement = mapConstantToLocalCopy(Aliasee, VM, &Materializer); |
| GA->setAliasee(Replacement); |
| } |
| |
| for (auto *GV : Drop) |
| drop(*GV); |
| |
| return Obj.takeModule(); |
| } |
| |
| static void runLTOPasses(Module &M, TargetMachine &TM) { |
| if (const DataLayout *DL = TM.getDataLayout()) |
| M.setDataLayout(*DL); |
| |
| legacy::PassManager passes; |
| passes.add(createTargetTransformInfoWrapperPass(TM.getTargetIRAnalysis())); |
| |
| PassManagerBuilder PMB; |
| PMB.LibraryInfo = new TargetLibraryInfoImpl(Triple(TM.getTargetTriple())); |
| PMB.Inliner = createFunctionInliningPass(); |
| PMB.VerifyInput = true; |
| PMB.VerifyOutput = true; |
| 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 */ true); |
| } |
| |
| static void codegen(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); |
| |
| legacy::PassManager CodeGenPasses; |
| |
| SmallString<128> Filename; |
| if (!options::obj_path.empty()) |
| Filename = options::obj_path; |
| else if (options::TheOutputType == options::OT_SAVE_TEMPS) |
| Filename = output_name + ".o"; |
| |
| int FD; |
| bool TempOutFile = Filename.empty(); |
| if (TempOutFile) { |
| std::error_code EC = |
| sys::fs::createTemporaryFile("lto-llvm", "o", FD, Filename); |
| if (EC) |
| message(LDPL_FATAL, "Could not create temporary file: %s", |
| EC.message().c_str()); |
| } else { |
| std::error_code EC = |
| sys::fs::openFileForWrite(Filename.c_str(), FD, sys::fs::F_None); |
| if (EC) |
| message(LDPL_FATAL, "Could not open file: %s", EC.message().c_str()); |
| } |
| |
| { |
| raw_fd_ostream OS(FD, true); |
| |
| if (TM->addPassesToEmitFile(CodeGenPasses, OS, |
| TargetMachine::CGFT_ObjectFile)) |
| message(LDPL_FATAL, "Failed to setup codegen"); |
| CodeGenPasses.run(M); |
| } |
| |
| 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; |
| |
| LLVMContext Context; |
| Context.setDiagnosticHandler(diagnosticHandler, nullptr, true); |
| |
| std::unique_ptr<Module> Combined(new Module("ld-temp.o", Context)); |
| Linker L(Combined.get()); |
| |
| std::string DefaultTriple = sys::getDefaultTargetTriple(); |
| |
| StringSet<> Internalize; |
| StringSet<> Maybe; |
| for (claimed_file &F : Modules) { |
| ld_plugin_input_file File; |
| if (get_input_file(F.handle, &File) != LDPS_OK) |
| message(LDPL_FATAL, "Failed to get file information"); |
| std::unique_ptr<Module> M = |
| getModuleForFile(Context, F, File, ApiFile, Internalize, Maybe); |
| if (!options::triple.empty()) |
| M->setTargetTriple(options::triple.c_str()); |
| else if (M->getTargetTriple().empty()) { |
| M->setTargetTriple(DefaultTriple); |
| } |
| |
| if (L.linkInModule(M.get())) |
| message(LDPL_FATAL, "Failed to link module"); |
| if (release_input_file(F.handle) != LDPS_OK) |
| message(LDPL_FATAL, "Failed to release file information"); |
| } |
| |
| 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, *L.getModule()); |
| if (options::TheOutputType == options::OT_BC_ONLY) |
| return LDPS_OK; |
| } |
| |
| codegen(*L.getModule()); |
| |
| 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; |
| } |