| //===-- llvm-lto: a simple command-line program to link modules with LTO --===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This program takes in a list of bitcode files, links them, performs link-time |
| // optimization, and outputs an object file. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/ADT/StringSet.h" |
| #include "llvm/Bitcode/ReaderWriter.h" |
| #include "llvm/CodeGen/CommandFlags.h" |
| #include "llvm/IR/DiagnosticPrinter.h" |
| #include "llvm/IR/LLVMContext.h" |
| #include "llvm/LTO/LTOCodeGenerator.h" |
| #include "llvm/LTO/LTOModule.h" |
| #include "llvm/Object/FunctionIndexObjectFile.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/FileSystem.h" |
| #include "llvm/Support/ManagedStatic.h" |
| #include "llvm/Support/PrettyStackTrace.h" |
| #include "llvm/Support/Signals.h" |
| #include "llvm/Support/TargetSelect.h" |
| #include "llvm/Support/ToolOutputFile.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include <list> |
| |
| using namespace llvm; |
| |
| static cl::opt<char> |
| OptLevel("O", |
| cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] " |
| "(default = '-O2')"), |
| cl::Prefix, |
| cl::ZeroOrMore, |
| cl::init('2')); |
| |
| static cl::opt<bool> DisableVerify( |
| "disable-verify", cl::init(false), |
| cl::desc("Do not run the verifier during the optimization pipeline")); |
| |
| static cl::opt<bool> |
| DisableInline("disable-inlining", cl::init(false), |
| cl::desc("Do not run the inliner pass")); |
| |
| static cl::opt<bool> |
| DisableGVNLoadPRE("disable-gvn-loadpre", cl::init(false), |
| cl::desc("Do not run the GVN load PRE pass")); |
| |
| static cl::opt<bool> |
| DisableLTOVectorization("disable-lto-vectorization", cl::init(false), |
| cl::desc("Do not run loop or slp vectorization during LTO")); |
| |
| static cl::opt<bool> |
| UseDiagnosticHandler("use-diagnostic-handler", cl::init(false), |
| cl::desc("Use a diagnostic handler to test the handler interface")); |
| |
| static cl::opt<bool> |
| ThinLTO("thinlto", cl::init(false), |
| cl::desc("Only write combined global index for ThinLTO backends")); |
| |
| static cl::opt<bool> |
| SaveModuleFile("save-merged-module", cl::init(false), |
| cl::desc("Write merged LTO module to file before CodeGen")); |
| |
| static cl::list<std::string> |
| InputFilenames(cl::Positional, cl::OneOrMore, |
| cl::desc("<input bitcode files>")); |
| |
| static cl::opt<std::string> |
| OutputFilename("o", cl::init(""), |
| cl::desc("Override output filename"), |
| cl::value_desc("filename")); |
| |
| static cl::list<std::string> |
| ExportedSymbols("exported-symbol", |
| cl::desc("Symbol to export from the resulting object file"), |
| cl::ZeroOrMore); |
| |
| static cl::list<std::string> |
| DSOSymbols("dso-symbol", |
| cl::desc("Symbol to put in the symtab in the resulting dso"), |
| cl::ZeroOrMore); |
| |
| static cl::opt<bool> ListSymbolsOnly( |
| "list-symbols-only", cl::init(false), |
| cl::desc("Instead of running LTO, list the symbols in each IR file")); |
| |
| static cl::opt<bool> SetMergedModule( |
| "set-merged-module", cl::init(false), |
| cl::desc("Use the first input module as the merged module")); |
| |
| static cl::opt<unsigned> Parallelism("j", cl::Prefix, cl::init(1), |
| cl::desc("Number of backend threads")); |
| |
| namespace { |
| struct ModuleInfo { |
| std::vector<bool> CanBeHidden; |
| }; |
| } |
| |
| static void handleDiagnostics(lto_codegen_diagnostic_severity_t Severity, |
| const char *Msg, void *) { |
| errs() << "llvm-lto: "; |
| switch (Severity) { |
| case LTO_DS_NOTE: |
| errs() << "note: "; |
| break; |
| case LTO_DS_REMARK: |
| errs() << "remark: "; |
| break; |
| case LTO_DS_ERROR: |
| errs() << "error: "; |
| break; |
| case LTO_DS_WARNING: |
| errs() << "warning: "; |
| break; |
| } |
| errs() << Msg << "\n"; |
| } |
| |
| static std::string CurrentActivity; |
| static void diagnosticHandler(const DiagnosticInfo &DI) { |
| raw_ostream &OS = errs(); |
| OS << "llvm-lto: "; |
| switch (DI.getSeverity()) { |
| case DS_Error: |
| OS << "error"; |
| break; |
| case DS_Warning: |
| OS << "warning"; |
| break; |
| case DS_Remark: |
| OS << "remark"; |
| break; |
| case DS_Note: |
| OS << "note"; |
| break; |
| } |
| if (!CurrentActivity.empty()) |
| OS << ' ' << CurrentActivity; |
| OS << ": "; |
| |
| DiagnosticPrinterRawOStream DP(OS); |
| DI.print(DP); |
| OS << '\n'; |
| |
| if (DI.getSeverity() == DS_Error) |
| exit(1); |
| } |
| |
| static void diagnosticHandlerWithContenxt(const DiagnosticInfo &DI, |
| void *Context) { |
| diagnosticHandler(DI); |
| } |
| |
| static void error(const Twine &Msg) { |
| errs() << "llvm-lto: " << Msg << '\n'; |
| exit(1); |
| } |
| |
| static void error(std::error_code EC, const Twine &Prefix) { |
| if (EC) |
| error(Prefix + ": " + EC.message()); |
| } |
| |
| template <typename T> |
| static void error(const ErrorOr<T> &V, const Twine &Prefix) { |
| error(V.getError(), Prefix); |
| } |
| |
| static std::unique_ptr<LTOModule> |
| getLocalLTOModule(StringRef Path, std::unique_ptr<MemoryBuffer> &Buffer, |
| const TargetOptions &Options) { |
| ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr = |
| MemoryBuffer::getFile(Path); |
| error(BufferOrErr, "error loading file '" + Path + "'"); |
| Buffer = std::move(BufferOrErr.get()); |
| CurrentActivity = ("loading file '" + Path + "'").str(); |
| ErrorOr<std::unique_ptr<LTOModule>> Ret = LTOModule::createInLocalContext( |
| Buffer->getBufferStart(), Buffer->getBufferSize(), Options, Path); |
| CurrentActivity = ""; |
| return std::move(*Ret); |
| } |
| |
| /// \brief List symbols in each IR file. |
| /// |
| /// The main point here is to provide lit-testable coverage for the LTOModule |
| /// functionality that's exposed by the C API to list symbols. Moreover, this |
| /// provides testing coverage for modules that have been created in their own |
| /// contexts. |
| static void listSymbols(const TargetOptions &Options) { |
| for (auto &Filename : InputFilenames) { |
| std::unique_ptr<MemoryBuffer> Buffer; |
| std::unique_ptr<LTOModule> Module = |
| getLocalLTOModule(Filename, Buffer, Options); |
| |
| // List the symbols. |
| outs() << Filename << ":\n"; |
| for (int I = 0, E = Module->getSymbolCount(); I != E; ++I) |
| outs() << Module->getSymbolName(I) << "\n"; |
| } |
| } |
| |
| /// Create a combined index file from the input IR files and write it. |
| /// |
| /// This is meant to enable testing of ThinLTO combined index generation, |
| /// currently available via the gold plugin via -thinlto. |
| static void createCombinedFunctionIndex() { |
| FunctionInfoIndex CombinedIndex; |
| uint64_t NextModuleId = 0; |
| for (auto &Filename : InputFilenames) { |
| CurrentActivity = "loading file '" + Filename + "'"; |
| ErrorOr<std::unique_ptr<FunctionInfoIndex>> IndexOrErr = |
| llvm::getFunctionIndexForFile(Filename, diagnosticHandler); |
| std::unique_ptr<FunctionInfoIndex> Index = std::move(IndexOrErr.get()); |
| CurrentActivity = ""; |
| // Skip files without a function summary. |
| if (!Index) |
| continue; |
| CombinedIndex.mergeFrom(std::move(Index), ++NextModuleId); |
| } |
| std::error_code EC; |
| assert(!OutputFilename.empty()); |
| raw_fd_ostream OS(OutputFilename + ".thinlto.bc", EC, |
| sys::fs::OpenFlags::F_None); |
| error(EC, "error opening the file '" + OutputFilename + ".thinlto.bc'"); |
| WriteFunctionSummaryToFile(CombinedIndex, OS); |
| OS.close(); |
| } |
| |
| int main(int argc, char **argv) { |
| // Print a stack trace if we signal out. |
| sys::PrintStackTraceOnErrorSignal(); |
| PrettyStackTraceProgram X(argc, argv); |
| |
| llvm_shutdown_obj Y; // Call llvm_shutdown() on exit. |
| cl::ParseCommandLineOptions(argc, argv, "llvm LTO linker\n"); |
| |
| if (OptLevel < '0' || OptLevel > '3') |
| error("optimization level must be between 0 and 3"); |
| |
| // Initialize the configured targets. |
| InitializeAllTargets(); |
| InitializeAllTargetMCs(); |
| InitializeAllAsmPrinters(); |
| InitializeAllAsmParsers(); |
| |
| // set up the TargetOptions for the machine |
| TargetOptions Options = InitTargetOptionsFromCodeGenFlags(); |
| |
| if (ListSymbolsOnly) { |
| listSymbols(Options); |
| return 0; |
| } |
| |
| if (ThinLTO) { |
| createCombinedFunctionIndex(); |
| return 0; |
| } |
| |
| unsigned BaseArg = 0; |
| |
| LLVMContext Context; |
| Context.setDiagnosticHandler(diagnosticHandlerWithContenxt, nullptr, true); |
| |
| LTOCodeGenerator CodeGen(Context); |
| |
| if (UseDiagnosticHandler) |
| CodeGen.setDiagnosticHandler(handleDiagnostics, nullptr); |
| |
| CodeGen.setCodePICModel(RelocModel); |
| |
| CodeGen.setDebugInfo(LTO_DEBUG_MODEL_DWARF); |
| CodeGen.setTargetOptions(Options); |
| |
| llvm::StringSet<llvm::MallocAllocator> DSOSymbolsSet; |
| for (unsigned i = 0; i < DSOSymbols.size(); ++i) |
| DSOSymbolsSet.insert(DSOSymbols[i]); |
| |
| std::vector<std::string> KeptDSOSyms; |
| |
| for (unsigned i = BaseArg; i < InputFilenames.size(); ++i) { |
| CurrentActivity = "loading file '" + InputFilenames[i] + "'"; |
| ErrorOr<std::unique_ptr<LTOModule>> ModuleOrErr = |
| LTOModule::createFromFile(Context, InputFilenames[i].c_str(), Options); |
| error(ModuleOrErr, "error " + CurrentActivity); |
| std::unique_ptr<LTOModule> &Module = *ModuleOrErr; |
| CurrentActivity = ""; |
| |
| unsigned NumSyms = Module->getSymbolCount(); |
| for (unsigned I = 0; I < NumSyms; ++I) { |
| StringRef Name = Module->getSymbolName(I); |
| if (!DSOSymbolsSet.count(Name)) |
| continue; |
| lto_symbol_attributes Attrs = Module->getSymbolAttributes(I); |
| unsigned Scope = Attrs & LTO_SYMBOL_SCOPE_MASK; |
| if (Scope != LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN) |
| KeptDSOSyms.push_back(Name); |
| } |
| |
| // We use the first input module as the destination module when |
| // SetMergedModule is true. |
| if (SetMergedModule && i == BaseArg) { |
| // Transfer ownership to the code generator. |
| CodeGen.setModule(std::move(Module)); |
| } else if (!CodeGen.addModule(Module.get())) { |
| // Print a message here so that we know addModule() did not abort. |
| errs() << argv[0] << ": error adding file '" << InputFilenames[i] << "'\n"; |
| return 1; |
| } |
| } |
| |
| // Add all the exported symbols to the table of symbols to preserve. |
| for (unsigned i = 0; i < ExportedSymbols.size(); ++i) |
| CodeGen.addMustPreserveSymbol(ExportedSymbols[i].c_str()); |
| |
| // Add all the dso symbols to the table of symbols to expose. |
| for (unsigned i = 0; i < KeptDSOSyms.size(); ++i) |
| CodeGen.addMustPreserveSymbol(KeptDSOSyms[i].c_str()); |
| |
| // Set cpu and attrs strings for the default target/subtarget. |
| CodeGen.setCpu(MCPU.c_str()); |
| |
| CodeGen.setOptLevel(OptLevel - '0'); |
| |
| std::string attrs; |
| for (unsigned i = 0; i < MAttrs.size(); ++i) { |
| if (i > 0) |
| attrs.append(","); |
| attrs.append(MAttrs[i]); |
| } |
| |
| if (!attrs.empty()) |
| CodeGen.setAttr(attrs.c_str()); |
| |
| if (FileType.getNumOccurrences()) |
| CodeGen.setFileType(FileType); |
| |
| if (!OutputFilename.empty()) { |
| if (!CodeGen.optimize(DisableVerify, DisableInline, DisableGVNLoadPRE, |
| DisableLTOVectorization)) { |
| // Diagnostic messages should have been printed by the handler. |
| errs() << argv[0] << ": error optimizing the code\n"; |
| return 1; |
| } |
| |
| if (SaveModuleFile) { |
| std::string ModuleFilename = OutputFilename; |
| ModuleFilename += ".merged.bc"; |
| std::string ErrMsg; |
| |
| if (!CodeGen.writeMergedModules(ModuleFilename.c_str())) { |
| errs() << argv[0] << ": writing merged module failed.\n"; |
| return 1; |
| } |
| } |
| |
| std::list<tool_output_file> OSs; |
| std::vector<raw_pwrite_stream *> OSPtrs; |
| for (unsigned I = 0; I != Parallelism; ++I) { |
| std::string PartFilename = OutputFilename; |
| if (Parallelism != 1) |
| PartFilename += "." + utostr(I); |
| std::error_code EC; |
| OSs.emplace_back(PartFilename, EC, sys::fs::F_None); |
| if (EC) { |
| errs() << argv[0] << ": error opening the file '" << PartFilename |
| << "': " << EC.message() << "\n"; |
| return 1; |
| } |
| OSPtrs.push_back(&OSs.back().os()); |
| } |
| |
| if (!CodeGen.compileOptimized(OSPtrs)) { |
| // Diagnostic messages should have been printed by the handler. |
| errs() << argv[0] << ": error compiling the code\n"; |
| return 1; |
| } |
| |
| for (tool_output_file &OS : OSs) |
| OS.keep(); |
| } else { |
| if (Parallelism != 1) { |
| errs() << argv[0] << ": -j must be specified together with -o\n"; |
| return 1; |
| } |
| |
| if (SaveModuleFile) { |
| errs() << argv[0] << ": -save-merged-module must be specified with -o\n"; |
| return 1; |
| } |
| |
| const char *OutputName = nullptr; |
| if (!CodeGen.compile_to_file(&OutputName, DisableVerify, DisableInline, |
| DisableGVNLoadPRE, DisableLTOVectorization)) { |
| // Diagnostic messages should have been printed by the handler. |
| errs() << argv[0] << ": error compiling the code\n"; |
| return 1; |
| } |
| |
| outs() << "Wrote native object file '" << OutputName << "'\n"; |
| } |
| |
| return 0; |
| } |