| //===-LTO.cpp - LLVM Link Time Optimizer ----------------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements functions and classes used to support LTO. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/LTO/LTO.h" |
| #include "llvm/ADT/Statistic.h" |
| #include "llvm/Analysis/TargetLibraryInfo.h" |
| #include "llvm/Analysis/TargetTransformInfo.h" |
| #include "llvm/Bitcode/BitcodeReader.h" |
| #include "llvm/Bitcode/BitcodeWriter.h" |
| #include "llvm/CodeGen/Analysis.h" |
| #include "llvm/Config/llvm-config.h" |
| #include "llvm/IR/AutoUpgrade.h" |
| #include "llvm/IR/DiagnosticPrinter.h" |
| #include "llvm/IR/LegacyPassManager.h" |
| #include "llvm/IR/Mangler.h" |
| #include "llvm/IR/Metadata.h" |
| #include "llvm/LTO/LTOBackend.h" |
| #include "llvm/Linker/IRMover.h" |
| #include "llvm/Object/IRObjectFile.h" |
| #include "llvm/Support/Error.h" |
| #include "llvm/Support/ManagedStatic.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Support/Path.h" |
| #include "llvm/Support/SHA1.h" |
| #include "llvm/Support/SourceMgr.h" |
| #include "llvm/Support/TargetRegistry.h" |
| #include "llvm/Support/ThreadPool.h" |
| #include "llvm/Support/Threading.h" |
| #include "llvm/Support/VCSRevision.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/Target/TargetMachine.h" |
| #include "llvm/Target/TargetOptions.h" |
| #include "llvm/Transforms/IPO.h" |
| #include "llvm/Transforms/IPO/PassManagerBuilder.h" |
| #include "llvm/Transforms/Utils/SplitModule.h" |
| |
| #include <set> |
| |
| using namespace llvm; |
| using namespace lto; |
| using namespace object; |
| |
| #define DEBUG_TYPE "lto" |
| |
| static cl::opt<bool> |
| DumpThinCGSCCs("dump-thin-cg-sccs", cl::init(false), cl::Hidden, |
| cl::desc("Dump the SCCs in the ThinLTO index's callgraph")); |
| |
| // The values are (type identifier, summary) pairs. |
| typedef DenseMap< |
| GlobalValue::GUID, |
| TinyPtrVector<const std::pair<const std::string, TypeIdSummary> *>> |
| TypeIdSummariesByGuidTy; |
| |
| // Returns a unique hash for the Module considering the current list of |
| // export/import and other global analysis results. |
| // The hash is produced in \p Key. |
| static void computeCacheKey( |
| SmallString<40> &Key, const Config &Conf, const ModuleSummaryIndex &Index, |
| StringRef ModuleID, const FunctionImporter::ImportMapTy &ImportList, |
| const FunctionImporter::ExportSetTy &ExportList, |
| const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR, |
| const GVSummaryMapTy &DefinedGlobals, |
| const TypeIdSummariesByGuidTy &TypeIdSummariesByGuid, |
| const std::set<GlobalValue::GUID> &CfiFunctionDefs, |
| const std::set<GlobalValue::GUID> &CfiFunctionDecls) { |
| // Compute the unique hash for this entry. |
| // This is based on the current compiler version, the module itself, the |
| // export list, the hash for every single module in the import list, the |
| // list of ResolvedODR for the module, and the list of preserved symbols. |
| SHA1 Hasher; |
| |
| // Start with the compiler revision |
| Hasher.update(LLVM_VERSION_STRING); |
| #ifdef LLVM_REVISION |
| Hasher.update(LLVM_REVISION); |
| #endif |
| |
| // Include the parts of the LTO configuration that affect code generation. |
| auto AddString = [&](StringRef Str) { |
| Hasher.update(Str); |
| Hasher.update(ArrayRef<uint8_t>{0}); |
| }; |
| auto AddUnsigned = [&](unsigned I) { |
| uint8_t Data[4]; |
| Data[0] = I; |
| Data[1] = I >> 8; |
| Data[2] = I >> 16; |
| Data[3] = I >> 24; |
| Hasher.update(ArrayRef<uint8_t>{Data, 4}); |
| }; |
| auto AddUint64 = [&](uint64_t I) { |
| uint8_t Data[8]; |
| Data[0] = I; |
| Data[1] = I >> 8; |
| Data[2] = I >> 16; |
| Data[3] = I >> 24; |
| Data[4] = I >> 32; |
| Data[5] = I >> 40; |
| Data[6] = I >> 48; |
| Data[7] = I >> 56; |
| Hasher.update(ArrayRef<uint8_t>{Data, 8}); |
| }; |
| AddString(Conf.CPU); |
| // FIXME: Hash more of Options. For now all clients initialize Options from |
| // command-line flags (which is unsupported in production), but may set |
| // RelaxELFRelocations. The clang driver can also pass FunctionSections, |
| // DataSections and DebuggerTuning via command line flags. |
| AddUnsigned(Conf.Options.RelaxELFRelocations); |
| AddUnsigned(Conf.Options.FunctionSections); |
| AddUnsigned(Conf.Options.DataSections); |
| AddUnsigned((unsigned)Conf.Options.DebuggerTuning); |
| for (auto &A : Conf.MAttrs) |
| AddString(A); |
| if (Conf.RelocModel) |
| AddUnsigned(*Conf.RelocModel); |
| else |
| AddUnsigned(-1); |
| if (Conf.CodeModel) |
| AddUnsigned(*Conf.CodeModel); |
| else |
| AddUnsigned(-1); |
| AddUnsigned(Conf.CGOptLevel); |
| AddUnsigned(Conf.CGFileType); |
| AddUnsigned(Conf.OptLevel); |
| AddUnsigned(Conf.UseNewPM); |
| AddString(Conf.OptPipeline); |
| AddString(Conf.AAPipeline); |
| AddString(Conf.OverrideTriple); |
| AddString(Conf.DefaultTriple); |
| AddString(Conf.DwoDir); |
| |
| // Include the hash for the current module |
| auto ModHash = Index.getModuleHash(ModuleID); |
| Hasher.update(ArrayRef<uint8_t>((uint8_t *)&ModHash[0], sizeof(ModHash))); |
| for (auto F : ExportList) |
| // The export list can impact the internalization, be conservative here |
| Hasher.update(ArrayRef<uint8_t>((uint8_t *)&F, sizeof(F))); |
| |
| // Include the hash for every module we import functions from. The set of |
| // imported symbols for each module may affect code generation and is |
| // sensitive to link order, so include that as well. |
| for (auto &Entry : ImportList) { |
| auto ModHash = Index.getModuleHash(Entry.first()); |
| Hasher.update(ArrayRef<uint8_t>((uint8_t *)&ModHash[0], sizeof(ModHash))); |
| |
| AddUint64(Entry.second.size()); |
| for (auto &Fn : Entry.second) |
| AddUint64(Fn); |
| } |
| |
| // Include the hash for the resolved ODR. |
| for (auto &Entry : ResolvedODR) { |
| Hasher.update(ArrayRef<uint8_t>((const uint8_t *)&Entry.first, |
| sizeof(GlobalValue::GUID))); |
| Hasher.update(ArrayRef<uint8_t>((const uint8_t *)&Entry.second, |
| sizeof(GlobalValue::LinkageTypes))); |
| } |
| |
| // Members of CfiFunctionDefs and CfiFunctionDecls that are referenced or |
| // defined in this module. |
| std::set<GlobalValue::GUID> UsedCfiDefs; |
| std::set<GlobalValue::GUID> UsedCfiDecls; |
| |
| // Typeids used in this module. |
| std::set<GlobalValue::GUID> UsedTypeIds; |
| |
| auto AddUsedCfiGlobal = [&](GlobalValue::GUID ValueGUID) { |
| if (CfiFunctionDefs.count(ValueGUID)) |
| UsedCfiDefs.insert(ValueGUID); |
| if (CfiFunctionDecls.count(ValueGUID)) |
| UsedCfiDecls.insert(ValueGUID); |
| }; |
| |
| auto AddUsedThings = [&](GlobalValueSummary *GS) { |
| if (!GS) return; |
| AddUnsigned(GS->isLive()); |
| for (const ValueInfo &VI : GS->refs()) { |
| AddUnsigned(VI.isDSOLocal()); |
| AddUsedCfiGlobal(VI.getGUID()); |
| } |
| if (auto *FS = dyn_cast<FunctionSummary>(GS)) { |
| for (auto &TT : FS->type_tests()) |
| UsedTypeIds.insert(TT); |
| for (auto &TT : FS->type_test_assume_vcalls()) |
| UsedTypeIds.insert(TT.GUID); |
| for (auto &TT : FS->type_checked_load_vcalls()) |
| UsedTypeIds.insert(TT.GUID); |
| for (auto &TT : FS->type_test_assume_const_vcalls()) |
| UsedTypeIds.insert(TT.VFunc.GUID); |
| for (auto &TT : FS->type_checked_load_const_vcalls()) |
| UsedTypeIds.insert(TT.VFunc.GUID); |
| for (auto &ET : FS->calls()) { |
| AddUnsigned(ET.first.isDSOLocal()); |
| AddUsedCfiGlobal(ET.first.getGUID()); |
| } |
| } |
| }; |
| |
| // Include the hash for the linkage type to reflect internalization and weak |
| // resolution, and collect any used type identifier resolutions. |
| for (auto &GS : DefinedGlobals) { |
| GlobalValue::LinkageTypes Linkage = GS.second->linkage(); |
| Hasher.update( |
| ArrayRef<uint8_t>((const uint8_t *)&Linkage, sizeof(Linkage))); |
| AddUsedCfiGlobal(GS.first); |
| AddUsedThings(GS.second); |
| } |
| |
| // Imported functions may introduce new uses of type identifier resolutions, |
| // so we need to collect their used resolutions as well. |
| for (auto &ImpM : ImportList) |
| for (auto &ImpF : ImpM.second) |
| AddUsedThings(Index.findSummaryInModule(ImpF, ImpM.first())); |
| |
| auto AddTypeIdSummary = [&](StringRef TId, const TypeIdSummary &S) { |
| AddString(TId); |
| |
| AddUnsigned(S.TTRes.TheKind); |
| AddUnsigned(S.TTRes.SizeM1BitWidth); |
| |
| AddUint64(S.TTRes.AlignLog2); |
| AddUint64(S.TTRes.SizeM1); |
| AddUint64(S.TTRes.BitMask); |
| AddUint64(S.TTRes.InlineBits); |
| |
| AddUint64(S.WPDRes.size()); |
| for (auto &WPD : S.WPDRes) { |
| AddUnsigned(WPD.first); |
| AddUnsigned(WPD.second.TheKind); |
| AddString(WPD.second.SingleImplName); |
| |
| AddUint64(WPD.second.ResByArg.size()); |
| for (auto &ByArg : WPD.second.ResByArg) { |
| AddUint64(ByArg.first.size()); |
| for (uint64_t Arg : ByArg.first) |
| AddUint64(Arg); |
| AddUnsigned(ByArg.second.TheKind); |
| AddUint64(ByArg.second.Info); |
| AddUnsigned(ByArg.second.Byte); |
| AddUnsigned(ByArg.second.Bit); |
| } |
| } |
| }; |
| |
| // Include the hash for all type identifiers used by this module. |
| for (GlobalValue::GUID TId : UsedTypeIds) { |
| auto SummariesI = TypeIdSummariesByGuid.find(TId); |
| if (SummariesI != TypeIdSummariesByGuid.end()) |
| for (auto *Summary : SummariesI->second) |
| AddTypeIdSummary(Summary->first, Summary->second); |
| } |
| |
| AddUnsigned(UsedCfiDefs.size()); |
| for (auto &V : UsedCfiDefs) |
| AddUint64(V); |
| |
| AddUnsigned(UsedCfiDecls.size()); |
| for (auto &V : UsedCfiDecls) |
| AddUint64(V); |
| |
| if (!Conf.SampleProfile.empty()) { |
| auto FileOrErr = MemoryBuffer::getFile(Conf.SampleProfile); |
| if (FileOrErr) |
| Hasher.update(FileOrErr.get()->getBuffer()); |
| } |
| |
| Key = toHex(Hasher.result()); |
| } |
| |
| static void thinLTOResolveWeakForLinkerGUID( |
| GlobalValueSummaryList &GVSummaryList, GlobalValue::GUID GUID, |
| DenseSet<GlobalValueSummary *> &GlobalInvolvedWithAlias, |
| function_ref<bool(GlobalValue::GUID, const GlobalValueSummary *)> |
| isPrevailing, |
| function_ref<void(StringRef, GlobalValue::GUID, GlobalValue::LinkageTypes)> |
| recordNewLinkage) { |
| for (auto &S : GVSummaryList) { |
| GlobalValue::LinkageTypes OriginalLinkage = S->linkage(); |
| if (!GlobalValue::isWeakForLinker(OriginalLinkage)) |
| continue; |
| // We need to emit only one of these. The prevailing module will keep it, |
| // but turned into a weak, while the others will drop it when possible. |
| // This is both a compile-time optimization and a correctness |
| // transformation. This is necessary for correctness when we have exported |
| // a reference - we need to convert the linkonce to weak to |
| // ensure a copy is kept to satisfy the exported reference. |
| // FIXME: We may want to split the compile time and correctness |
| // aspects into separate routines. |
| if (isPrevailing(GUID, S.get())) { |
| if (GlobalValue::isLinkOnceLinkage(OriginalLinkage)) |
| S->setLinkage(GlobalValue::getWeakLinkage( |
| GlobalValue::isLinkOnceODRLinkage(OriginalLinkage))); |
| } |
| // Alias and aliasee can't be turned into available_externally. |
| else if (!isa<AliasSummary>(S.get()) && |
| !GlobalInvolvedWithAlias.count(S.get())) |
| S->setLinkage(GlobalValue::AvailableExternallyLinkage); |
| if (S->linkage() != OriginalLinkage) |
| recordNewLinkage(S->modulePath(), GUID, S->linkage()); |
| } |
| } |
| |
| // Resolve Weak and LinkOnce values in the \p Index. |
| // |
| // We'd like to drop these functions if they are no longer referenced in the |
| // current module. However there is a chance that another module is still |
| // referencing them because of the import. We make sure we always emit at least |
| // one copy. |
| void llvm::thinLTOResolveWeakForLinkerInIndex( |
| ModuleSummaryIndex &Index, |
| function_ref<bool(GlobalValue::GUID, const GlobalValueSummary *)> |
| isPrevailing, |
| function_ref<void(StringRef, GlobalValue::GUID, GlobalValue::LinkageTypes)> |
| recordNewLinkage) { |
| // We won't optimize the globals that are referenced by an alias for now |
| // Ideally we should turn the alias into a global and duplicate the definition |
| // when needed. |
| DenseSet<GlobalValueSummary *> GlobalInvolvedWithAlias; |
| for (auto &I : Index) |
| for (auto &S : I.second.SummaryList) |
| if (auto AS = dyn_cast<AliasSummary>(S.get())) |
| GlobalInvolvedWithAlias.insert(&AS->getAliasee()); |
| |
| for (auto &I : Index) |
| thinLTOResolveWeakForLinkerGUID(I.second.SummaryList, I.first, |
| GlobalInvolvedWithAlias, isPrevailing, |
| recordNewLinkage); |
| } |
| |
| static void thinLTOInternalizeAndPromoteGUID( |
| GlobalValueSummaryList &GVSummaryList, GlobalValue::GUID GUID, |
| function_ref<bool(StringRef, GlobalValue::GUID)> isExported) { |
| for (auto &S : GVSummaryList) { |
| if (isExported(S->modulePath(), GUID)) { |
| if (GlobalValue::isLocalLinkage(S->linkage())) |
| S->setLinkage(GlobalValue::ExternalLinkage); |
| } else if (!GlobalValue::isLocalLinkage(S->linkage())) |
| S->setLinkage(GlobalValue::InternalLinkage); |
| } |
| } |
| |
| // Update the linkages in the given \p Index to mark exported values |
| // as external and non-exported values as internal. |
| void llvm::thinLTOInternalizeAndPromoteInIndex( |
| ModuleSummaryIndex &Index, |
| function_ref<bool(StringRef, GlobalValue::GUID)> isExported) { |
| for (auto &I : Index) |
| thinLTOInternalizeAndPromoteGUID(I.second.SummaryList, I.first, isExported); |
| } |
| |
| // Requires a destructor for std::vector<InputModule>. |
| InputFile::~InputFile() = default; |
| |
| Expected<std::unique_ptr<InputFile>> InputFile::create(MemoryBufferRef Object) { |
| std::unique_ptr<InputFile> File(new InputFile); |
| |
| Expected<IRSymtabFile> FOrErr = readIRSymtab(Object); |
| if (!FOrErr) |
| return FOrErr.takeError(); |
| |
| File->TargetTriple = FOrErr->TheReader.getTargetTriple(); |
| File->SourceFileName = FOrErr->TheReader.getSourceFileName(); |
| File->COFFLinkerOpts = FOrErr->TheReader.getCOFFLinkerOpts(); |
| File->ComdatTable = FOrErr->TheReader.getComdatTable(); |
| |
| for (unsigned I = 0; I != FOrErr->Mods.size(); ++I) { |
| size_t Begin = File->Symbols.size(); |
| for (const irsymtab::Reader::SymbolRef &Sym : |
| FOrErr->TheReader.module_symbols(I)) |
| // Skip symbols that are irrelevant to LTO. Note that this condition needs |
| // to match the one in Skip() in LTO::addRegularLTO(). |
| if (Sym.isGlobal() && !Sym.isFormatSpecific()) |
| File->Symbols.push_back(Sym); |
| File->ModuleSymIndices.push_back({Begin, File->Symbols.size()}); |
| } |
| |
| File->Mods = FOrErr->Mods; |
| File->Strtab = std::move(FOrErr->Strtab); |
| return std::move(File); |
| } |
| |
| StringRef InputFile::getName() const { |
| return Mods[0].getModuleIdentifier(); |
| } |
| |
| LTO::RegularLTOState::RegularLTOState(unsigned ParallelCodeGenParallelismLevel, |
| Config &Conf) |
| : ParallelCodeGenParallelismLevel(ParallelCodeGenParallelismLevel), |
| Ctx(Conf), CombinedModule(llvm::make_unique<Module>("ld-temp.o", Ctx)), |
| Mover(llvm::make_unique<IRMover>(*CombinedModule)) {} |
| |
| LTO::ThinLTOState::ThinLTOState(ThinBackend Backend) |
| : Backend(Backend), CombinedIndex(/*HaveGVs*/ false) { |
| if (!Backend) |
| this->Backend = |
| createInProcessThinBackend(llvm::heavyweight_hardware_concurrency()); |
| } |
| |
| LTO::LTO(Config Conf, ThinBackend Backend, |
| unsigned ParallelCodeGenParallelismLevel) |
| : Conf(std::move(Conf)), |
| RegularLTO(ParallelCodeGenParallelismLevel, this->Conf), |
| ThinLTO(std::move(Backend)) {} |
| |
| // Requires a destructor for MapVector<BitcodeModule>. |
| LTO::~LTO() = default; |
| |
| // Add the symbols in the given module to the GlobalResolutions map, and resolve |
| // their partitions. |
| void LTO::addModuleToGlobalRes(ArrayRef<InputFile::Symbol> Syms, |
| ArrayRef<SymbolResolution> Res, |
| unsigned Partition, bool InSummary) { |
| auto *ResI = Res.begin(); |
| auto *ResE = Res.end(); |
| (void)ResE; |
| for (const InputFile::Symbol &Sym : Syms) { |
| assert(ResI != ResE); |
| SymbolResolution Res = *ResI++; |
| |
| StringRef Name = Sym.getName(); |
| Triple TT(RegularLTO.CombinedModule->getTargetTriple()); |
| // Strip the __imp_ prefix from COFF dllimport symbols (similar to the |
| // way they are handled by lld), otherwise we can end up with two |
| // global resolutions (one with and one for a copy of the symbol without). |
| if (TT.isOSBinFormatCOFF() && Name.startswith("__imp_")) |
| Name = Name.substr(strlen("__imp_")); |
| auto &GlobalRes = GlobalResolutions[Name]; |
| GlobalRes.UnnamedAddr &= Sym.isUnnamedAddr(); |
| if (Res.Prevailing) { |
| assert(!GlobalRes.Prevailing && |
| "Multiple prevailing defs are not allowed"); |
| GlobalRes.Prevailing = true; |
| GlobalRes.IRName = Sym.getIRName(); |
| } else if (!GlobalRes.Prevailing && GlobalRes.IRName.empty()) { |
| // Sometimes it can be two copies of symbol in a module and prevailing |
| // symbol can have no IR name. That might happen if symbol is defined in |
| // module level inline asm block. In case we have multiple modules with |
| // the same symbol we want to use IR name of the prevailing symbol. |
| // Otherwise, if we haven't seen a prevailing symbol, set the name so that |
| // we can later use it to check if there is any prevailing copy in IR. |
| GlobalRes.IRName = Sym.getIRName(); |
| } |
| |
| // Set the partition to external if we know it is re-defined by the linker |
| // with -defsym or -wrap options, used elsewhere, e.g. it is visible to a |
| // regular object, is referenced from llvm.compiler_used, or was already |
| // recorded as being referenced from a different partition. |
| if (Res.LinkerRedefined || Res.VisibleToRegularObj || Sym.isUsed() || |
| (GlobalRes.Partition != GlobalResolution::Unknown && |
| GlobalRes.Partition != Partition)) { |
| GlobalRes.Partition = GlobalResolution::External; |
| } else |
| // First recorded reference, save the current partition. |
| GlobalRes.Partition = Partition; |
| |
| // Flag as visible outside of summary if visible from a regular object or |
| // from a module that does not have a summary. |
| GlobalRes.VisibleOutsideSummary |= |
| (Res.VisibleToRegularObj || Sym.isUsed() || !InSummary); |
| } |
| } |
| |
| static void writeToResolutionFile(raw_ostream &OS, InputFile *Input, |
| ArrayRef<SymbolResolution> Res) { |
| StringRef Path = Input->getName(); |
| OS << Path << '\n'; |
| auto ResI = Res.begin(); |
| for (const InputFile::Symbol &Sym : Input->symbols()) { |
| assert(ResI != Res.end()); |
| SymbolResolution Res = *ResI++; |
| |
| OS << "-r=" << Path << ',' << Sym.getName() << ','; |
| if (Res.Prevailing) |
| OS << 'p'; |
| if (Res.FinalDefinitionInLinkageUnit) |
| OS << 'l'; |
| if (Res.VisibleToRegularObj) |
| OS << 'x'; |
| if (Res.LinkerRedefined) |
| OS << 'r'; |
| OS << '\n'; |
| } |
| OS.flush(); |
| assert(ResI == Res.end()); |
| } |
| |
| Error LTO::add(std::unique_ptr<InputFile> Input, |
| ArrayRef<SymbolResolution> Res) { |
| assert(!CalledGetMaxTasks); |
| |
| if (Conf.ResolutionFile) |
| writeToResolutionFile(*Conf.ResolutionFile, Input.get(), Res); |
| |
| if (RegularLTO.CombinedModule->getTargetTriple().empty()) |
| RegularLTO.CombinedModule->setTargetTriple(Input->getTargetTriple()); |
| |
| const SymbolResolution *ResI = Res.begin(); |
| for (unsigned I = 0; I != Input->Mods.size(); ++I) |
| if (Error Err = addModule(*Input, I, ResI, Res.end())) |
| return Err; |
| |
| assert(ResI == Res.end()); |
| return Error::success(); |
| } |
| |
| Error LTO::addModule(InputFile &Input, unsigned ModI, |
| const SymbolResolution *&ResI, |
| const SymbolResolution *ResE) { |
| Expected<BitcodeLTOInfo> LTOInfo = Input.Mods[ModI].getLTOInfo(); |
| if (!LTOInfo) |
| return LTOInfo.takeError(); |
| |
| BitcodeModule BM = Input.Mods[ModI]; |
| auto ModSyms = Input.module_symbols(ModI); |
| addModuleToGlobalRes(ModSyms, {ResI, ResE}, |
| LTOInfo->IsThinLTO ? ThinLTO.ModuleMap.size() + 1 : 0, |
| LTOInfo->HasSummary); |
| |
| if (LTOInfo->IsThinLTO) |
| return addThinLTO(BM, ModSyms, ResI, ResE); |
| |
| Expected<RegularLTOState::AddedModule> ModOrErr = |
| addRegularLTO(BM, ModSyms, ResI, ResE); |
| if (!ModOrErr) |
| return ModOrErr.takeError(); |
| |
| if (!LTOInfo->HasSummary) |
| return linkRegularLTO(std::move(*ModOrErr), /*LivenessFromIndex=*/false); |
| |
| // Regular LTO module summaries are added to a dummy module that represents |
| // the combined regular LTO module. |
| if (Error Err = BM.readSummary(ThinLTO.CombinedIndex, "", -1ull)) |
| return Err; |
| RegularLTO.ModsWithSummaries.push_back(std::move(*ModOrErr)); |
| return Error::success(); |
| } |
| |
| // Checks whether the given global value is in a non-prevailing comdat |
| // (comdat containing values the linker indicated were not prevailing, |
| // which we then dropped to available_externally), and if so, removes |
| // it from the comdat. This is called for all global values to ensure the |
| // comdat is empty rather than leaving an incomplete comdat. It is needed for |
| // regular LTO modules, in case we are in a mixed-LTO mode (both regular |
| // and thin LTO modules) compilation. Since the regular LTO module will be |
| // linked first in the final native link, we want to make sure the linker |
| // doesn't select any of these incomplete comdats that would be left |
| // in the regular LTO module without this cleanup. |
| static void |
| handleNonPrevailingComdat(GlobalValue &GV, |
| std::set<const Comdat *> &NonPrevailingComdats) { |
| Comdat *C = GV.getComdat(); |
| if (!C) |
| return; |
| |
| if (!NonPrevailingComdats.count(C)) |
| return; |
| |
| // Additionally need to drop externally visible global values from the comdat |
| // to available_externally, so that there aren't multiply defined linker |
| // errors. |
| if (!GV.hasLocalLinkage()) |
| GV.setLinkage(GlobalValue::AvailableExternallyLinkage); |
| |
| if (auto GO = dyn_cast<GlobalObject>(&GV)) |
| GO->setComdat(nullptr); |
| } |
| |
| // Add a regular LTO object to the link. |
| // The resulting module needs to be linked into the combined LTO module with |
| // linkRegularLTO. |
| Expected<LTO::RegularLTOState::AddedModule> |
| LTO::addRegularLTO(BitcodeModule BM, ArrayRef<InputFile::Symbol> Syms, |
| const SymbolResolution *&ResI, |
| const SymbolResolution *ResE) { |
| RegularLTOState::AddedModule Mod; |
| Expected<std::unique_ptr<Module>> MOrErr = |
| BM.getLazyModule(RegularLTO.Ctx, /*ShouldLazyLoadMetadata*/ true, |
| /*IsImporting*/ false); |
| if (!MOrErr) |
| return MOrErr.takeError(); |
| Module &M = **MOrErr; |
| Mod.M = std::move(*MOrErr); |
| |
| if (Error Err = M.materializeMetadata()) |
| return std::move(Err); |
| UpgradeDebugInfo(M); |
| |
| ModuleSymbolTable SymTab; |
| SymTab.addModule(&M); |
| |
| for (GlobalVariable &GV : M.globals()) |
| if (GV.hasAppendingLinkage()) |
| Mod.Keep.push_back(&GV); |
| |
| DenseSet<GlobalObject *> AliasedGlobals; |
| for (auto &GA : M.aliases()) |
| if (GlobalObject *GO = GA.getBaseObject()) |
| AliasedGlobals.insert(GO); |
| |
| // In this function we need IR GlobalValues matching the symbols in Syms |
| // (which is not backed by a module), so we need to enumerate them in the same |
| // order. The symbol enumeration order of a ModuleSymbolTable intentionally |
| // matches the order of an irsymtab, but when we read the irsymtab in |
| // InputFile::create we omit some symbols that are irrelevant to LTO. The |
| // Skip() function skips the same symbols from the module as InputFile does |
| // from the symbol table. |
| auto MsymI = SymTab.symbols().begin(), MsymE = SymTab.symbols().end(); |
| auto Skip = [&]() { |
| while (MsymI != MsymE) { |
| auto Flags = SymTab.getSymbolFlags(*MsymI); |
| if ((Flags & object::BasicSymbolRef::SF_Global) && |
| !(Flags & object::BasicSymbolRef::SF_FormatSpecific)) |
| return; |
| ++MsymI; |
| } |
| }; |
| Skip(); |
| |
| std::set<const Comdat *> NonPrevailingComdats; |
| for (const InputFile::Symbol &Sym : Syms) { |
| assert(ResI != ResE); |
| SymbolResolution Res = *ResI++; |
| |
| assert(MsymI != MsymE); |
| ModuleSymbolTable::Symbol Msym = *MsymI++; |
| Skip(); |
| |
| if (GlobalValue *GV = Msym.dyn_cast<GlobalValue *>()) { |
| if (Res.Prevailing) { |
| if (Sym.isUndefined()) |
| continue; |
| Mod.Keep.push_back(GV); |
| // For symbols re-defined with linker -wrap and -defsym options, |
| // set the linkage to weak to inhibit IPO. The linkage will be |
| // restored by the linker. |
| if (Res.LinkerRedefined) |
| GV->setLinkage(GlobalValue::WeakAnyLinkage); |
| |
| GlobalValue::LinkageTypes OriginalLinkage = GV->getLinkage(); |
| if (GlobalValue::isLinkOnceLinkage(OriginalLinkage)) |
| GV->setLinkage(GlobalValue::getWeakLinkage( |
| GlobalValue::isLinkOnceODRLinkage(OriginalLinkage))); |
| } else if (isa<GlobalObject>(GV) && |
| (GV->hasLinkOnceODRLinkage() || GV->hasWeakODRLinkage() || |
| GV->hasAvailableExternallyLinkage()) && |
| !AliasedGlobals.count(cast<GlobalObject>(GV))) { |
| // Any of the above three types of linkage indicates that the |
| // chosen prevailing symbol will have the same semantics as this copy of |
| // the symbol, so we may be able to link it with available_externally |
| // linkage. We will decide later whether to do that when we link this |
| // module (in linkRegularLTO), based on whether it is undefined. |
| Mod.Keep.push_back(GV); |
| GV->setLinkage(GlobalValue::AvailableExternallyLinkage); |
| if (GV->hasComdat()) |
| NonPrevailingComdats.insert(GV->getComdat()); |
| cast<GlobalObject>(GV)->setComdat(nullptr); |
| } |
| |
| // Set the 'local' flag based on the linker resolution for this symbol. |
| if (Res.FinalDefinitionInLinkageUnit) |
| GV->setDSOLocal(true); |
| } |
| // Common resolution: collect the maximum size/alignment over all commons. |
| // We also record if we see an instance of a common as prevailing, so that |
| // if none is prevailing we can ignore it later. |
| if (Sym.isCommon()) { |
| // FIXME: We should figure out what to do about commons defined by asm. |
| // For now they aren't reported correctly by ModuleSymbolTable. |
| auto &CommonRes = RegularLTO.Commons[Sym.getIRName()]; |
| CommonRes.Size = std::max(CommonRes.Size, Sym.getCommonSize()); |
| CommonRes.Align = std::max(CommonRes.Align, Sym.getCommonAlignment()); |
| CommonRes.Prevailing |= Res.Prevailing; |
| } |
| |
| } |
| if (!M.getComdatSymbolTable().empty()) |
| for (GlobalValue &GV : M.global_values()) |
| handleNonPrevailingComdat(GV, NonPrevailingComdats); |
| assert(MsymI == MsymE); |
| return std::move(Mod); |
| } |
| |
| Error LTO::linkRegularLTO(RegularLTOState::AddedModule Mod, |
| bool LivenessFromIndex) { |
| std::vector<GlobalValue *> Keep; |
| for (GlobalValue *GV : Mod.Keep) { |
| if (LivenessFromIndex && !ThinLTO.CombinedIndex.isGUIDLive(GV->getGUID())) |
| continue; |
| |
| if (!GV->hasAvailableExternallyLinkage()) { |
| Keep.push_back(GV); |
| continue; |
| } |
| |
| // Only link available_externally definitions if we don't already have a |
| // definition. |
| GlobalValue *CombinedGV = |
| RegularLTO.CombinedModule->getNamedValue(GV->getName()); |
| if (CombinedGV && !CombinedGV->isDeclaration()) |
| continue; |
| |
| Keep.push_back(GV); |
| } |
| |
| return RegularLTO.Mover->move(std::move(Mod.M), Keep, |
| [](GlobalValue &, IRMover::ValueAdder) {}, |
| /* IsPerformingImport */ false); |
| } |
| |
| // Add a ThinLTO module to the link. |
| Error LTO::addThinLTO(BitcodeModule BM, ArrayRef<InputFile::Symbol> Syms, |
| const SymbolResolution *&ResI, |
| const SymbolResolution *ResE) { |
| if (Error Err = |
| BM.readSummary(ThinLTO.CombinedIndex, BM.getModuleIdentifier(), |
| ThinLTO.ModuleMap.size())) |
| return Err; |
| |
| for (const InputFile::Symbol &Sym : Syms) { |
| assert(ResI != ResE); |
| SymbolResolution Res = *ResI++; |
| |
| if (!Sym.getIRName().empty()) { |
| auto GUID = GlobalValue::getGUID(GlobalValue::getGlobalIdentifier( |
| Sym.getIRName(), GlobalValue::ExternalLinkage, "")); |
| if (Res.Prevailing) { |
| ThinLTO.PrevailingModuleForGUID[GUID] = BM.getModuleIdentifier(); |
| |
| // For linker redefined symbols (via --wrap or --defsym) we want to |
| // switch the linkage to `weak` to prevent IPOs from happening. |
| // Find the summary in the module for this very GV and record the new |
| // linkage so that we can switch it when we import the GV. |
| if (Res.LinkerRedefined) |
| if (auto S = ThinLTO.CombinedIndex.findSummaryInModule( |
| GUID, BM.getModuleIdentifier())) |
| S->setLinkage(GlobalValue::WeakAnyLinkage); |
| } |
| |
| // If the linker resolved the symbol to a local definition then mark it |
| // as local in the summary for the module we are adding. |
| if (Res.FinalDefinitionInLinkageUnit) { |
| if (auto S = ThinLTO.CombinedIndex.findSummaryInModule( |
| GUID, BM.getModuleIdentifier())) { |
| S->setDSOLocal(true); |
| } |
| } |
| } |
| } |
| |
| if (!ThinLTO.ModuleMap.insert({BM.getModuleIdentifier(), BM}).second) |
| return make_error<StringError>( |
| "Expected at most one ThinLTO module per bitcode file", |
| inconvertibleErrorCode()); |
| |
| return Error::success(); |
| } |
| |
| unsigned LTO::getMaxTasks() const { |
| CalledGetMaxTasks = true; |
| return RegularLTO.ParallelCodeGenParallelismLevel + ThinLTO.ModuleMap.size(); |
| } |
| |
| Error LTO::run(AddStreamFn AddStream, NativeObjectCache Cache) { |
| // Compute "dead" symbols, we don't want to import/export these! |
| DenseSet<GlobalValue::GUID> GUIDPreservedSymbols; |
| DenseMap<GlobalValue::GUID, PrevailingType> GUIDPrevailingResolutions; |
| for (auto &Res : GlobalResolutions) { |
| // Normally resolution have IR name of symbol. We can do nothing here |
| // otherwise. See comments in GlobalResolution struct for more details. |
| if (Res.second.IRName.empty()) |
| continue; |
| |
| GlobalValue::GUID GUID = GlobalValue::getGUID( |
| GlobalValue::dropLLVMManglingEscape(Res.second.IRName)); |
| |
| if (Res.second.VisibleOutsideSummary && Res.second.Prevailing) |
| GUIDPreservedSymbols.insert(GlobalValue::getGUID( |
| GlobalValue::dropLLVMManglingEscape(Res.second.IRName))); |
| |
| GUIDPrevailingResolutions[GUID] = |
| Res.second.Prevailing ? PrevailingType::Yes : PrevailingType::No; |
| } |
| |
| auto isPrevailing = [&](GlobalValue::GUID G) { |
| auto It = GUIDPrevailingResolutions.find(G); |
| if (It == GUIDPrevailingResolutions.end()) |
| return PrevailingType::Unknown; |
| return It->second; |
| }; |
| computeDeadSymbols(ThinLTO.CombinedIndex, GUIDPreservedSymbols, isPrevailing); |
| |
| // Setup output file to emit statistics. |
| std::unique_ptr<ToolOutputFile> StatsFile = nullptr; |
| if (!Conf.StatsFile.empty()) { |
| EnableStatistics(false); |
| std::error_code EC; |
| StatsFile = |
| llvm::make_unique<ToolOutputFile>(Conf.StatsFile, EC, sys::fs::F_None); |
| if (EC) |
| return errorCodeToError(EC); |
| StatsFile->keep(); |
| } |
| |
| Error Result = runRegularLTO(AddStream); |
| if (!Result) |
| Result = runThinLTO(AddStream, Cache); |
| |
| if (StatsFile) |
| PrintStatisticsJSON(StatsFile->os()); |
| |
| return Result; |
| } |
| |
| Error LTO::runRegularLTO(AddStreamFn AddStream) { |
| for (auto &M : RegularLTO.ModsWithSummaries) |
| if (Error Err = linkRegularLTO(std::move(M), |
| /*LivenessFromIndex=*/true)) |
| return Err; |
| |
| // Make sure commons have the right size/alignment: we kept the largest from |
| // all the prevailing when adding the inputs, and we apply it here. |
| const DataLayout &DL = RegularLTO.CombinedModule->getDataLayout(); |
| for (auto &I : RegularLTO.Commons) { |
| if (!I.second.Prevailing) |
| // Don't do anything if no instance of this common was prevailing. |
| continue; |
| GlobalVariable *OldGV = RegularLTO.CombinedModule->getNamedGlobal(I.first); |
| if (OldGV && DL.getTypeAllocSize(OldGV->getValueType()) == I.second.Size) { |
| // Don't create a new global if the type is already correct, just make |
| // sure the alignment is correct. |
| OldGV->setAlignment(I.second.Align); |
| continue; |
| } |
| ArrayType *Ty = |
| ArrayType::get(Type::getInt8Ty(RegularLTO.Ctx), I.second.Size); |
| auto *GV = new GlobalVariable(*RegularLTO.CombinedModule, Ty, false, |
| GlobalValue::CommonLinkage, |
| ConstantAggregateZero::get(Ty), ""); |
| GV->setAlignment(I.second.Align); |
| if (OldGV) { |
| OldGV->replaceAllUsesWith(ConstantExpr::getBitCast(GV, OldGV->getType())); |
| GV->takeName(OldGV); |
| OldGV->eraseFromParent(); |
| } else { |
| GV->setName(I.first); |
| } |
| } |
| |
| if (Conf.PreOptModuleHook && |
| !Conf.PreOptModuleHook(0, *RegularLTO.CombinedModule)) |
| return Error::success(); |
| |
| if (!Conf.CodeGenOnly) { |
| for (const auto &R : GlobalResolutions) { |
| if (!R.second.isPrevailingIRSymbol()) |
| continue; |
| if (R.second.Partition != 0 && |
| R.second.Partition != GlobalResolution::External) |
| continue; |
| |
| GlobalValue *GV = |
| RegularLTO.CombinedModule->getNamedValue(R.second.IRName); |
| // Ignore symbols defined in other partitions. |
| // Also skip declarations, which are not allowed to have internal linkage. |
| if (!GV || GV->hasLocalLinkage() || GV->isDeclaration()) |
| continue; |
| GV->setUnnamedAddr(R.second.UnnamedAddr ? GlobalValue::UnnamedAddr::Global |
| : GlobalValue::UnnamedAddr::None); |
| if (R.second.Partition == 0) |
| GV->setLinkage(GlobalValue::InternalLinkage); |
| } |
| |
| if (Conf.PostInternalizeModuleHook && |
| !Conf.PostInternalizeModuleHook(0, *RegularLTO.CombinedModule)) |
| return Error::success(); |
| } |
| return backend(Conf, AddStream, RegularLTO.ParallelCodeGenParallelismLevel, |
| std::move(RegularLTO.CombinedModule), ThinLTO.CombinedIndex); |
| } |
| |
| /// This class defines the interface to the ThinLTO backend. |
| class lto::ThinBackendProc { |
| protected: |
| Config &Conf; |
| ModuleSummaryIndex &CombinedIndex; |
| const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries; |
| |
| public: |
| ThinBackendProc(Config &Conf, ModuleSummaryIndex &CombinedIndex, |
| const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries) |
| : Conf(Conf), CombinedIndex(CombinedIndex), |
| ModuleToDefinedGVSummaries(ModuleToDefinedGVSummaries) {} |
| |
| virtual ~ThinBackendProc() {} |
| virtual Error start( |
| unsigned Task, BitcodeModule BM, |
| const FunctionImporter::ImportMapTy &ImportList, |
| const FunctionImporter::ExportSetTy &ExportList, |
| const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR, |
| MapVector<StringRef, BitcodeModule> &ModuleMap) = 0; |
| virtual Error wait() = 0; |
| }; |
| |
| namespace { |
| class InProcessThinBackend : public ThinBackendProc { |
| ThreadPool BackendThreadPool; |
| AddStreamFn AddStream; |
| NativeObjectCache Cache; |
| TypeIdSummariesByGuidTy TypeIdSummariesByGuid; |
| std::set<GlobalValue::GUID> CfiFunctionDefs; |
| std::set<GlobalValue::GUID> CfiFunctionDecls; |
| |
| Optional<Error> Err; |
| std::mutex ErrMu; |
| |
| public: |
| InProcessThinBackend( |
| Config &Conf, ModuleSummaryIndex &CombinedIndex, |
| unsigned ThinLTOParallelismLevel, |
| const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries, |
| AddStreamFn AddStream, NativeObjectCache Cache) |
| : ThinBackendProc(Conf, CombinedIndex, ModuleToDefinedGVSummaries), |
| BackendThreadPool(ThinLTOParallelismLevel), |
| AddStream(std::move(AddStream)), Cache(std::move(Cache)) { |
| // Create a mapping from type identifier GUIDs to type identifier summaries. |
| // This allows backends to use the type identifier GUIDs stored in the |
| // function summaries to determine which type identifier summaries affect |
| // each function without needing to compute GUIDs in each backend. |
| for (auto &TId : CombinedIndex.typeIds()) |
| TypeIdSummariesByGuid[GlobalValue::getGUID(TId.first)].push_back(&TId); |
| for (auto &Name : CombinedIndex.cfiFunctionDefs()) |
| CfiFunctionDefs.insert( |
| GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(Name))); |
| for (auto &Name : CombinedIndex.cfiFunctionDecls()) |
| CfiFunctionDecls.insert( |
| GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(Name))); |
| } |
| |
| Error runThinLTOBackendThread( |
| AddStreamFn AddStream, NativeObjectCache Cache, unsigned Task, |
| BitcodeModule BM, ModuleSummaryIndex &CombinedIndex, |
| const FunctionImporter::ImportMapTy &ImportList, |
| const FunctionImporter::ExportSetTy &ExportList, |
| const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR, |
| const GVSummaryMapTy &DefinedGlobals, |
| MapVector<StringRef, BitcodeModule> &ModuleMap, |
| const TypeIdSummariesByGuidTy &TypeIdSummariesByGuid) { |
| auto RunThinBackend = [&](AddStreamFn AddStream) { |
| LTOLLVMContext BackendContext(Conf); |
| Expected<std::unique_ptr<Module>> MOrErr = BM.parseModule(BackendContext); |
| if (!MOrErr) |
| return MOrErr.takeError(); |
| |
| return thinBackend(Conf, Task, AddStream, **MOrErr, CombinedIndex, |
| ImportList, DefinedGlobals, ModuleMap); |
| }; |
| |
| auto ModuleID = BM.getModuleIdentifier(); |
| |
| if (!Cache || !CombinedIndex.modulePaths().count(ModuleID) || |
| all_of(CombinedIndex.getModuleHash(ModuleID), |
| [](uint32_t V) { return V == 0; })) |
| // Cache disabled or no entry for this module in the combined index or |
| // no module hash. |
| return RunThinBackend(AddStream); |
| |
| SmallString<40> Key; |
| // The module may be cached, this helps handling it. |
| computeCacheKey(Key, Conf, CombinedIndex, ModuleID, ImportList, ExportList, |
| ResolvedODR, DefinedGlobals, TypeIdSummariesByGuid, |
| CfiFunctionDefs, CfiFunctionDecls); |
| if (AddStreamFn CacheAddStream = Cache(Task, Key)) |
| return RunThinBackend(CacheAddStream); |
| |
| return Error::success(); |
| } |
| |
| Error start( |
| unsigned Task, BitcodeModule BM, |
| const FunctionImporter::ImportMapTy &ImportList, |
| const FunctionImporter::ExportSetTy &ExportList, |
| const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR, |
| MapVector<StringRef, BitcodeModule> &ModuleMap) override { |
| StringRef ModulePath = BM.getModuleIdentifier(); |
| assert(ModuleToDefinedGVSummaries.count(ModulePath)); |
| const GVSummaryMapTy &DefinedGlobals = |
| ModuleToDefinedGVSummaries.find(ModulePath)->second; |
| BackendThreadPool.async( |
| [=](BitcodeModule BM, ModuleSummaryIndex &CombinedIndex, |
| const FunctionImporter::ImportMapTy &ImportList, |
| const FunctionImporter::ExportSetTy &ExportList, |
| const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> |
| &ResolvedODR, |
| const GVSummaryMapTy &DefinedGlobals, |
| MapVector<StringRef, BitcodeModule> &ModuleMap, |
| const TypeIdSummariesByGuidTy &TypeIdSummariesByGuid) { |
| Error E = runThinLTOBackendThread( |
| AddStream, Cache, Task, BM, CombinedIndex, ImportList, ExportList, |
| ResolvedODR, DefinedGlobals, ModuleMap, TypeIdSummariesByGuid); |
| if (E) { |
| std::unique_lock<std::mutex> L(ErrMu); |
| if (Err) |
| Err = joinErrors(std::move(*Err), std::move(E)); |
| else |
| Err = std::move(E); |
| } |
| }, |
| BM, std::ref(CombinedIndex), std::ref(ImportList), std::ref(ExportList), |
| std::ref(ResolvedODR), std::ref(DefinedGlobals), std::ref(ModuleMap), |
| std::ref(TypeIdSummariesByGuid)); |
| return Error::success(); |
| } |
| |
| Error wait() override { |
| BackendThreadPool.wait(); |
| if (Err) |
| return std::move(*Err); |
| else |
| return Error::success(); |
| } |
| }; |
| } // end anonymous namespace |
| |
| ThinBackend lto::createInProcessThinBackend(unsigned ParallelismLevel) { |
| return [=](Config &Conf, ModuleSummaryIndex &CombinedIndex, |
| const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries, |
| AddStreamFn AddStream, NativeObjectCache Cache) { |
| return llvm::make_unique<InProcessThinBackend>( |
| Conf, CombinedIndex, ParallelismLevel, ModuleToDefinedGVSummaries, |
| AddStream, Cache); |
| }; |
| } |
| |
| // 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. |
| std::string lto::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(); |
| } |
| |
| namespace { |
| class WriteIndexesThinBackend : public ThinBackendProc { |
| std::string OldPrefix, NewPrefix; |
| bool ShouldEmitImportsFiles; |
| raw_fd_ostream *LinkedObjectsFile; |
| lto::IndexWriteCallback OnWrite; |
| |
| public: |
| WriteIndexesThinBackend( |
| Config &Conf, ModuleSummaryIndex &CombinedIndex, |
| const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries, |
| std::string OldPrefix, std::string NewPrefix, bool ShouldEmitImportsFiles, |
| raw_fd_ostream *LinkedObjectsFile, lto::IndexWriteCallback OnWrite) |
| : ThinBackendProc(Conf, CombinedIndex, ModuleToDefinedGVSummaries), |
| OldPrefix(OldPrefix), NewPrefix(NewPrefix), |
| ShouldEmitImportsFiles(ShouldEmitImportsFiles), |
| LinkedObjectsFile(LinkedObjectsFile), OnWrite(OnWrite) {} |
| |
| Error start( |
| unsigned Task, BitcodeModule BM, |
| const FunctionImporter::ImportMapTy &ImportList, |
| const FunctionImporter::ExportSetTy &ExportList, |
| const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR, |
| MapVector<StringRef, BitcodeModule> &ModuleMap) override { |
| StringRef ModulePath = BM.getModuleIdentifier(); |
| std::string NewModulePath = |
| getThinLTOOutputFile(ModulePath, OldPrefix, NewPrefix); |
| |
| if (LinkedObjectsFile) |
| *LinkedObjectsFile << NewModulePath << '\n'; |
| |
| std::map<std::string, GVSummaryMapTy> ModuleToSummariesForIndex; |
| gatherImportedSummariesForModule(ModulePath, ModuleToDefinedGVSummaries, |
| ImportList, ModuleToSummariesForIndex); |
| |
| std::error_code EC; |
| raw_fd_ostream OS(NewModulePath + ".thinlto.bc", EC, |
| sys::fs::OpenFlags::F_None); |
| if (EC) |
| return errorCodeToError(EC); |
| WriteIndexToFile(CombinedIndex, OS, &ModuleToSummariesForIndex); |
| |
| if (ShouldEmitImportsFiles) { |
| EC = EmitImportsFiles(ModulePath, NewModulePath + ".imports", |
| ModuleToSummariesForIndex); |
| if (EC) |
| return errorCodeToError(EC); |
| } |
| |
| if (OnWrite) |
| OnWrite(ModulePath); |
| return Error::success(); |
| } |
| |
| Error wait() override { return Error::success(); } |
| }; |
| } // end anonymous namespace |
| |
| ThinBackend lto::createWriteIndexesThinBackend( |
| std::string OldPrefix, std::string NewPrefix, bool ShouldEmitImportsFiles, |
| raw_fd_ostream *LinkedObjectsFile, IndexWriteCallback OnWrite) { |
| return [=](Config &Conf, ModuleSummaryIndex &CombinedIndex, |
| const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries, |
| AddStreamFn AddStream, NativeObjectCache Cache) { |
| return llvm::make_unique<WriteIndexesThinBackend>( |
| Conf, CombinedIndex, ModuleToDefinedGVSummaries, OldPrefix, NewPrefix, |
| ShouldEmitImportsFiles, LinkedObjectsFile, OnWrite); |
| }; |
| } |
| |
| Error LTO::runThinLTO(AddStreamFn AddStream, NativeObjectCache Cache) { |
| if (ThinLTO.ModuleMap.empty()) |
| return Error::success(); |
| |
| if (Conf.CombinedIndexHook && !Conf.CombinedIndexHook(ThinLTO.CombinedIndex)) |
| return Error::success(); |
| |
| // Collect for each module the list of function it defines (GUID -> |
| // Summary). |
| StringMap<GVSummaryMapTy> |
| ModuleToDefinedGVSummaries(ThinLTO.ModuleMap.size()); |
| ThinLTO.CombinedIndex.collectDefinedGVSummariesPerModule( |
| ModuleToDefinedGVSummaries); |
| // Create entries for any modules that didn't have any GV summaries |
| // (either they didn't have any GVs to start with, or we suppressed |
| // generation of the summaries because they e.g. had inline assembly |
| // uses that couldn't be promoted/renamed on export). This is so |
| // InProcessThinBackend::start can still launch a backend thread, which |
| // is passed the map of summaries for the module, without any special |
| // handling for this case. |
| for (auto &Mod : ThinLTO.ModuleMap) |
| if (!ModuleToDefinedGVSummaries.count(Mod.first)) |
| ModuleToDefinedGVSummaries.try_emplace(Mod.first); |
| |
| StringMap<FunctionImporter::ImportMapTy> ImportLists( |
| ThinLTO.ModuleMap.size()); |
| StringMap<FunctionImporter::ExportSetTy> ExportLists( |
| ThinLTO.ModuleMap.size()); |
| StringMap<std::map<GlobalValue::GUID, GlobalValue::LinkageTypes>> ResolvedODR; |
| |
| if (DumpThinCGSCCs) |
| ThinLTO.CombinedIndex.dumpSCCs(outs()); |
| |
| if (Conf.OptLevel > 0) |
| ComputeCrossModuleImport(ThinLTO.CombinedIndex, ModuleToDefinedGVSummaries, |
| ImportLists, ExportLists); |
| |
| // Figure out which symbols need to be internalized. This also needs to happen |
| // at -O0 because summary-based DCE is implemented using internalization, and |
| // we must apply DCE consistently with the full LTO module in order to avoid |
| // undefined references during the final link. |
| std::set<GlobalValue::GUID> ExportedGUIDs; |
| for (auto &Res : GlobalResolutions) { |
| // If the symbol does not have external references or it is not prevailing, |
| // then not need to mark it as exported from a ThinLTO partition. |
| if (Res.second.Partition != GlobalResolution::External || |
| !Res.second.isPrevailingIRSymbol()) |
| continue; |
| auto GUID = GlobalValue::getGUID( |
| GlobalValue::dropLLVMManglingEscape(Res.second.IRName)); |
| // Mark exported unless index-based analysis determined it to be dead. |
| if (ThinLTO.CombinedIndex.isGUIDLive(GUID)) |
| ExportedGUIDs.insert(GUID); |
| } |
| |
| // Any functions referenced by the jump table in the regular LTO object must |
| // be exported. |
| for (auto &Def : ThinLTO.CombinedIndex.cfiFunctionDefs()) |
| ExportedGUIDs.insert( |
| GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(Def))); |
| |
| auto isExported = [&](StringRef ModuleIdentifier, GlobalValue::GUID GUID) { |
| const auto &ExportList = ExportLists.find(ModuleIdentifier); |
| return (ExportList != ExportLists.end() && |
| ExportList->second.count(GUID)) || |
| ExportedGUIDs.count(GUID); |
| }; |
| thinLTOInternalizeAndPromoteInIndex(ThinLTO.CombinedIndex, isExported); |
| |
| auto isPrevailing = [&](GlobalValue::GUID GUID, |
| const GlobalValueSummary *S) { |
| return ThinLTO.PrevailingModuleForGUID[GUID] == S->modulePath(); |
| }; |
| auto recordNewLinkage = [&](StringRef ModuleIdentifier, |
| GlobalValue::GUID GUID, |
| GlobalValue::LinkageTypes NewLinkage) { |
| ResolvedODR[ModuleIdentifier][GUID] = NewLinkage; |
| }; |
| thinLTOResolveWeakForLinkerInIndex(ThinLTO.CombinedIndex, isPrevailing, |
| recordNewLinkage); |
| |
| std::unique_ptr<ThinBackendProc> BackendProc = |
| ThinLTO.Backend(Conf, ThinLTO.CombinedIndex, ModuleToDefinedGVSummaries, |
| AddStream, Cache); |
| |
| // Tasks 0 through ParallelCodeGenParallelismLevel-1 are reserved for combined |
| // module and parallel code generation partitions. |
| unsigned Task = RegularLTO.ParallelCodeGenParallelismLevel; |
| for (auto &Mod : ThinLTO.ModuleMap) { |
| if (Error E = BackendProc->start(Task, Mod.second, ImportLists[Mod.first], |
| ExportLists[Mod.first], |
| ResolvedODR[Mod.first], ThinLTO.ModuleMap)) |
| return E; |
| ++Task; |
| } |
| |
| return BackendProc->wait(); |
| } |
| |
| Expected<std::unique_ptr<ToolOutputFile>> |
| lto::setupOptimizationRemarks(LLVMContext &Context, |
| StringRef LTORemarksFilename, |
| bool LTOPassRemarksWithHotness, int Count) { |
| if (LTOPassRemarksWithHotness) |
| Context.setDiagnosticsHotnessRequested(true); |
| if (LTORemarksFilename.empty()) |
| return nullptr; |
| |
| std::string Filename = LTORemarksFilename; |
| if (Count != -1) |
| Filename += ".thin." + llvm::utostr(Count) + ".yaml"; |
| |
| std::error_code EC; |
| auto DiagnosticFile = |
| llvm::make_unique<ToolOutputFile>(Filename, EC, sys::fs::F_None); |
| if (EC) |
| return errorCodeToError(EC); |
| Context.setDiagnosticsOutputFile( |
| llvm::make_unique<yaml::Output>(DiagnosticFile->os())); |
| DiagnosticFile->keep(); |
| return std::move(DiagnosticFile); |
| } |
