granicus.if.org Git - clang/blob - lib/CodeGen/BackendUtil.cpp

   1 //===--- BackendUtil.cpp - LLVM Backend Utilities -------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "clang/CodeGen/BackendUtil.h"
  11 #include "clang/Basic/Diagnostic.h"
  12 #include "clang/Basic/LangOptions.h"
  13 #include "clang/Basic/TargetOptions.h"
  14 #include "clang/Frontend/CodeGenOptions.h"
  15 #include "clang/Frontend/FrontendDiagnostic.h"
  16 #include "clang/Frontend/Utils.h"
  17 #include "clang/Lex/HeaderSearchOptions.h"
  18 #include "llvm/ADT/SmallSet.h"
  19 #include "llvm/ADT/StringExtras.h"
  20 #include "llvm/ADT/StringSwitch.h"
  21 #include "llvm/ADT/Triple.h"
  22 #include "llvm/Analysis/TargetLibraryInfo.h"
  23 #include "llvm/Analysis/TargetTransformInfo.h"
  24 #include "llvm/Bitcode/BitcodeReader.h"
  25 #include "llvm/Bitcode/BitcodeWriter.h"
  26 #include "llvm/Bitcode/BitcodeWriterPass.h"
  27 #include "llvm/CodeGen/RegAllocRegistry.h"
  28 #include "llvm/CodeGen/SchedulerRegistry.h"
  29 #include "llvm/IR/DataLayout.h"
  30 #include "llvm/IR/IRPrintingPasses.h"
  31 #include "llvm/IR/LegacyPassManager.h"
  32 #include "llvm/IR/Module.h"
  33 #include "llvm/IR/ModuleSummaryIndex.h"
  34 #include "llvm/IR/Verifier.h"
  35 #include "llvm/LTO/LTOBackend.h"
  36 #include "llvm/MC/MCAsmInfo.h"
  37 #include "llvm/MC/SubtargetFeature.h"
  38 #include "llvm/Passes/PassBuilder.h"
  39 #include "llvm/Support/CommandLine.h"
  40 #include "llvm/Support/MemoryBuffer.h"
  41 #include "llvm/Support/PrettyStackTrace.h"
  42 #include "llvm/Support/TargetRegistry.h"
  43 #include "llvm/Support/Timer.h"
  44 #include "llvm/Support/raw_ostream.h"
  45 #include "llvm/Target/TargetMachine.h"
  46 #include "llvm/Target/TargetOptions.h"
  47 #include "llvm/Target/TargetSubtargetInfo.h"
  48 #include "llvm/Transforms/Coroutines.h"
  49 #include "llvm/Transforms/IPO.h"
  50 #include "llvm/Transforms/IPO/AlwaysInliner.h"
  51 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
  52 #include "llvm/Transforms/Instrumentation.h"
  53 #include "llvm/Transforms/ObjCARC.h"
  54 #include "llvm/Transforms/Scalar.h"
  55 #include "llvm/Transforms/Scalar/GVN.h"
  56 #include "llvm/Transforms/Utils/SymbolRewriter.h"
  57 #include <memory>
  58 using namespace clang;
  59 using namespace llvm;
  60
  61 namespace {
  62
  63 // Default filename used for profile generation.
  64 static constexpr StringLiteral DefaultProfileGenName = "default_%m.profraw";
  65
  66 class EmitAssemblyHelper {
  67   DiagnosticsEngine &Diags;
  68   const HeaderSearchOptions &HSOpts;
  69   const CodeGenOptions &CodeGenOpts;
  70   const clang::TargetOptions &TargetOpts;
  71   const LangOptions &LangOpts;
  72   Module *TheModule;
  73
  74   Timer CodeGenerationTime;
  75
  76   std::unique_ptr<raw_pwrite_stream> OS;
  77
  78   TargetIRAnalysis getTargetIRAnalysis() const {
  79     if (TM)
  80       return TM->getTargetIRAnalysis();
  81
  82     return TargetIRAnalysis();
  83   }
  84
  85   void CreatePasses(legacy::PassManager &MPM, legacy::FunctionPassManager &FPM);
  86
  87   /// Generates the TargetMachine.
  88   /// Leaves TM unchanged if it is unable to create the target machine.
  89   /// Some of our clang tests specify triples which are not built
  90   /// into clang. This is okay because these tests check the generated
  91   /// IR, and they require DataLayout which depends on the triple.
  92   /// In this case, we allow this method to fail and not report an error.
  93   /// When MustCreateTM is used, we print an error if we are unable to load
  94   /// the requested target.
  95   void CreateTargetMachine(bool MustCreateTM);
  96
  97   /// Add passes necessary to emit assembly or LLVM IR.
  98   ///
  99   /// \return True on success.
 100   bool AddEmitPasses(legacy::PassManager &CodeGenPasses, BackendAction Action,
 101                      raw_pwrite_stream &OS);
 102
 103 public:
 104   EmitAssemblyHelper(DiagnosticsEngine &_Diags,
 105                      const HeaderSearchOptions &HeaderSearchOpts,
 106                      const CodeGenOptions &CGOpts,
 107                      const clang::TargetOptions &TOpts,
 108                      const LangOptions &LOpts, Module *M)
 109       : Diags(_Diags), HSOpts(HeaderSearchOpts), CodeGenOpts(CGOpts),
 110         TargetOpts(TOpts), LangOpts(LOpts), TheModule(M),
 111         CodeGenerationTime("codegen", "Code Generation Time") {}
 112
 113   ~EmitAssemblyHelper() {
 114     if (CodeGenOpts.DisableFree)
 115       BuryPointer(std::move(TM));
 116   }
 117
 118   std::unique_ptr<TargetMachine> TM;
 119
 120   void EmitAssembly(BackendAction Action,
 121                     std::unique_ptr<raw_pwrite_stream> OS);
 122
 123   void EmitAssemblyWithNewPassManager(BackendAction Action,
 124                                       std::unique_ptr<raw_pwrite_stream> OS);
 125 };
 126
 127 // We need this wrapper to access LangOpts and CGOpts from extension functions
 128 // that we add to the PassManagerBuilder.
 129 class PassManagerBuilderWrapper : public PassManagerBuilder {
 130 public:
 131   PassManagerBuilderWrapper(const Triple &TargetTriple,
 132                             const CodeGenOptions &CGOpts,
 133                             const LangOptions &LangOpts)
 134       : PassManagerBuilder(), TargetTriple(TargetTriple), CGOpts(CGOpts),
 135         LangOpts(LangOpts) {}
 136   const Triple &getTargetTriple() const { return TargetTriple; }
 137   const CodeGenOptions &getCGOpts() const { return CGOpts; }
 138   const LangOptions &getLangOpts() const { return LangOpts; }
 139
 140 private:
 141   const Triple &TargetTriple;
 142   const CodeGenOptions &CGOpts;
 143   const LangOptions &LangOpts;
 144 };
 145 }
 146
 147 static void addObjCARCAPElimPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
 148   if (Builder.OptLevel > 0)
 149     PM.add(createObjCARCAPElimPass());
 150 }
 151
 152 static void addObjCARCExpandPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
 153   if (Builder.OptLevel > 0)
 154     PM.add(createObjCARCExpandPass());
 155 }
 156
 157 static void addObjCARCOptPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
 158   if (Builder.OptLevel > 0)
 159     PM.add(createObjCARCOptPass());
 160 }
 161
 162 static void addAddDiscriminatorsPass(const PassManagerBuilder &Builder,
 163                                      legacy::PassManagerBase &PM) {
 164   PM.add(createAddDiscriminatorsPass());
 165 }
 166
 167 static void addBoundsCheckingPass(const PassManagerBuilder &Builder,
 168                                   legacy::PassManagerBase &PM) {
 169   PM.add(createBoundsCheckingPass());
 170 }
 171
 172 static void addSanitizerCoveragePass(const PassManagerBuilder &Builder,
 173                                      legacy::PassManagerBase &PM) {
 174   const PassManagerBuilderWrapper &BuilderWrapper =
 175       static_cast<const PassManagerBuilderWrapper&>(Builder);
 176   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
 177   SanitizerCoverageOptions Opts;
 178   Opts.CoverageType =
 179       static_cast<SanitizerCoverageOptions::Type>(CGOpts.SanitizeCoverageType);
 180   Opts.IndirectCalls = CGOpts.SanitizeCoverageIndirectCalls;
 181   Opts.TraceBB = CGOpts.SanitizeCoverageTraceBB;
 182   Opts.TraceCmp = CGOpts.SanitizeCoverageTraceCmp;
 183   Opts.TraceDiv = CGOpts.SanitizeCoverageTraceDiv;
 184   Opts.TraceGep = CGOpts.SanitizeCoverageTraceGep;
 185   Opts.Use8bitCounters = CGOpts.SanitizeCoverage8bitCounters;
 186   Opts.TracePC = CGOpts.SanitizeCoverageTracePC;
 187   Opts.TracePCGuard = CGOpts.SanitizeCoverageTracePCGuard;
 188   Opts.NoPrune = CGOpts.SanitizeCoverageNoPrune;
 189   PM.add(createSanitizerCoverageModulePass(Opts));
 190 }
 191
 192 // Check if ASan should use GC-friendly instrumentation for globals.
 193 // First of all, there is no point if -fdata-sections is off (expect for MachO,
 194 // where this is not a factor). Also, on ELF this feature requires an assembler
 195 // extension that only works with -integrated-as at the moment.
 196 static bool asanUseGlobalsGC(const Triple &T, const CodeGenOptions &CGOpts) {
 197   if (!CGOpts.SanitizeAddressGlobalsDeadStripping)
 198     return false;
 199   switch (T.getObjectFormat()) {
 200   case Triple::MachO:
 201   case Triple::COFF:
 202     return true;
 203   case Triple::ELF:
 204     return CGOpts.DataSections && !CGOpts.DisableIntegratedAS;
 205   default:
 206     return false;
 207   }
 208 }
 209
 210 static void addAddressSanitizerPasses(const PassManagerBuilder &Builder,
 211                                       legacy::PassManagerBase &PM) {
 212   const PassManagerBuilderWrapper &BuilderWrapper =
 213       static_cast<const PassManagerBuilderWrapper&>(Builder);
 214   const Triple &T = BuilderWrapper.getTargetTriple();
 215   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
 216   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Address);
 217   bool UseAfterScope = CGOpts.SanitizeAddressUseAfterScope;
 218   bool UseGlobalsGC = asanUseGlobalsGC(T, CGOpts);
 219   PM.add(createAddressSanitizerFunctionPass(/*CompileKernel*/ false, Recover,
 220                                             UseAfterScope));
 221   PM.add(createAddressSanitizerModulePass(/*CompileKernel*/ false, Recover,
 222                                           UseGlobalsGC));
 223 }
 224
 225 static void addKernelAddressSanitizerPasses(const PassManagerBuilder &Builder,
 226                                             legacy::PassManagerBase &PM) {
 227   PM.add(createAddressSanitizerFunctionPass(
 228       /*CompileKernel*/ true,
 229       /*Recover*/ true, /*UseAfterScope*/ false));
 230   PM.add(createAddressSanitizerModulePass(/*CompileKernel*/true,
 231                                           /*Recover*/true));
 232 }
 233
 234 static void addMemorySanitizerPass(const PassManagerBuilder &Builder,
 235                                    legacy::PassManagerBase &PM) {
 236   const PassManagerBuilderWrapper &BuilderWrapper =
 237       static_cast<const PassManagerBuilderWrapper&>(Builder);
 238   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
 239   int TrackOrigins = CGOpts.SanitizeMemoryTrackOrigins;
 240   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Memory);
 241   PM.add(createMemorySanitizerPass(TrackOrigins, Recover));
 242
 243   // MemorySanitizer inserts complex instrumentation that mostly follows
 244   // the logic of the original code, but operates on "shadow" values.
 245   // It can benefit from re-running some general purpose optimization passes.
 246   if (Builder.OptLevel > 0) {
 247     PM.add(createEarlyCSEPass());
 248     PM.add(createReassociatePass());
 249     PM.add(createLICMPass());
 250     PM.add(createGVNPass());
 251     PM.add(createInstructionCombiningPass());
 252     PM.add(createDeadStoreEliminationPass());
 253   }
 254 }
 255
 256 static void addThreadSanitizerPass(const PassManagerBuilder &Builder,
 257                                    legacy::PassManagerBase &PM) {
 258   PM.add(createThreadSanitizerPass());
 259 }
 260
 261 static void addDataFlowSanitizerPass(const PassManagerBuilder &Builder,
 262                                      legacy::PassManagerBase &PM) {
 263   const PassManagerBuilderWrapper &BuilderWrapper =
 264       static_cast<const PassManagerBuilderWrapper&>(Builder);
 265   const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
 266   PM.add(createDataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
 267 }
 268
 269 static void addEfficiencySanitizerPass(const PassManagerBuilder &Builder,
 270                                        legacy::PassManagerBase &PM) {
 271   const PassManagerBuilderWrapper &BuilderWrapper =
 272       static_cast<const PassManagerBuilderWrapper&>(Builder);
 273   const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
 274   EfficiencySanitizerOptions Opts;
 275   if (LangOpts.Sanitize.has(SanitizerKind::EfficiencyCacheFrag))
 276     Opts.ToolType = EfficiencySanitizerOptions::ESAN_CacheFrag;
 277   else if (LangOpts.Sanitize.has(SanitizerKind::EfficiencyWorkingSet))
 278     Opts.ToolType = EfficiencySanitizerOptions::ESAN_WorkingSet;
 279   PM.add(createEfficiencySanitizerPass(Opts));
 280 }
 281
 282 static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
 283                                          const CodeGenOptions &CodeGenOpts) {
 284   TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple);
 285   if (!CodeGenOpts.SimplifyLibCalls)
 286     TLII->disableAllFunctions();
 287   else {
 288     // Disable individual libc/libm calls in TargetLibraryInfo.
 289     LibFunc F;
 290     for (auto &FuncName : CodeGenOpts.getNoBuiltinFuncs())
 291       if (TLII->getLibFunc(FuncName, F))
 292         TLII->setUnavailable(F);
 293   }
 294
 295   switch (CodeGenOpts.getVecLib()) {
 296   case CodeGenOptions::Accelerate:
 297     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::Accelerate);
 298     break;
 299   case CodeGenOptions::SVML:
 300     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::SVML);
 301     break;
 302   default:
 303     break;
 304   }
 305   return TLII;
 306 }
 307
 308 static void addSymbolRewriterPass(const CodeGenOptions &Opts,
 309                                   legacy::PassManager *MPM) {
 310   llvm::SymbolRewriter::RewriteDescriptorList DL;
 311
 312   llvm::SymbolRewriter::RewriteMapParser MapParser;
 313   for (const auto &MapFile : Opts.RewriteMapFiles)
 314     MapParser.parse(MapFile, &DL);
 315
 316   MPM->add(createRewriteSymbolsPass(DL));
 317 }
 318
 319 static CodeGenOpt::Level getCGOptLevel(const CodeGenOptions &CodeGenOpts) {
 320   switch (CodeGenOpts.OptimizationLevel) {
 321   default:
 322     llvm_unreachable("Invalid optimization level!");
 323   case 0:
 324     return CodeGenOpt::None;
 325   case 1:
 326     return CodeGenOpt::Less;
 327   case 2:
 328     return CodeGenOpt::Default; // O2/Os/Oz
 329   case 3:
 330     return CodeGenOpt::Aggressive;
 331   }
 332 }
 333
 334 static llvm::CodeModel::Model getCodeModel(const CodeGenOptions &CodeGenOpts) {
 335   unsigned CodeModel =
 336       llvm::StringSwitch<unsigned>(CodeGenOpts.CodeModel)
 337       .Case("small", llvm::CodeModel::Small)
 338       .Case("kernel", llvm::CodeModel::Kernel)
 339       .Case("medium", llvm::CodeModel::Medium)
 340       .Case("large", llvm::CodeModel::Large)
 341       .Case("default", llvm::CodeModel::Default)
 342       .Default(~0u);
 343   assert(CodeModel != ~0u && "invalid code model!");
 344   return static_cast<llvm::CodeModel::Model>(CodeModel);
 345 }
 346
 347 static llvm::Reloc::Model getRelocModel(const CodeGenOptions &CodeGenOpts) {
 348   // Keep this synced with the equivalent code in
 349   // lib/Frontend/CompilerInvocation.cpp
 350   llvm::Optional<llvm::Reloc::Model> RM;
 351   RM = llvm::StringSwitch<llvm::Reloc::Model>(CodeGenOpts.RelocationModel)
 352       .Case("static", llvm::Reloc::Static)
 353       .Case("pic", llvm::Reloc::PIC_)
 354       .Case("ropi", llvm::Reloc::ROPI)
 355       .Case("rwpi", llvm::Reloc::RWPI)
 356       .Case("ropi-rwpi", llvm::Reloc::ROPI_RWPI)
 357       .Case("dynamic-no-pic", llvm::Reloc::DynamicNoPIC);
 358   assert(RM.hasValue() && "invalid PIC model!");
 359   return *RM;
 360 }
 361
 362 static TargetMachine::CodeGenFileType getCodeGenFileType(BackendAction Action) {
 363   if (Action == Backend_EmitObj)
 364     return TargetMachine::CGFT_ObjectFile;
 365   else if (Action == Backend_EmitMCNull)
 366     return TargetMachine::CGFT_Null;
 367   else {
 368     assert(Action == Backend_EmitAssembly && "Invalid action!");
 369     return TargetMachine::CGFT_AssemblyFile;
 370   }
 371 }
 372
 373 static void initTargetOptions(llvm::TargetOptions &Options,
 374                               const CodeGenOptions &CodeGenOpts,
 375                               const clang::TargetOptions &TargetOpts,
 376                               const LangOptions &LangOpts,
 377                               const HeaderSearchOptions &HSOpts) {
 378   Options.ThreadModel =
 379       llvm::StringSwitch<llvm::ThreadModel::Model>(CodeGenOpts.ThreadModel)
 380           .Case("posix", llvm::ThreadModel::POSIX)
 381           .Case("single", llvm::ThreadModel::Single);
 382
 383   // Set float ABI type.
 384   assert((CodeGenOpts.FloatABI == "soft" || CodeGenOpts.FloatABI == "softfp" ||
 385           CodeGenOpts.FloatABI == "hard" || CodeGenOpts.FloatABI.empty()) &&
 386          "Invalid Floating Point ABI!");
 387   Options.FloatABIType =
 388       llvm::StringSwitch<llvm::FloatABI::ABIType>(CodeGenOpts.FloatABI)
 389           .Case("soft", llvm::FloatABI::Soft)
 390           .Case("softfp", llvm::FloatABI::Soft)
 391           .Case("hard", llvm::FloatABI::Hard)
 392           .Default(llvm::FloatABI::Default);
 393
 394   // Set FP fusion mode.
 395   switch (LangOpts.getDefaultFPContractMode()) {
 396   case LangOptions::FPC_Off:
 397     // Preserve any contraction performed by the front-end.  (Strict performs
 398     // splitting of the muladd instrinsic in the backend.)
 399     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
 400     break;
 401   case LangOptions::FPC_On:
 402     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
 403     break;
 404   case LangOptions::FPC_Fast:
 405     Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
 406     break;
 407   }
 408
 409   Options.UseInitArray = CodeGenOpts.UseInitArray;
 410   Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
 411   Options.CompressDebugSections = CodeGenOpts.CompressDebugSections;
 412   Options.RelaxELFRelocations = CodeGenOpts.RelaxELFRelocations;
 413
 414   // Set EABI version.
 415   Options.EABIVersion = llvm::StringSwitch<llvm::EABI>(TargetOpts.EABIVersion)
 416                             .Case("4", llvm::EABI::EABI4)
 417                             .Case("5", llvm::EABI::EABI5)
 418                             .Case("gnu", llvm::EABI::GNU)
 419                             .Default(llvm::EABI::Default);
 420
 421   if (LangOpts.SjLjExceptions)
 422     Options.ExceptionModel = llvm::ExceptionHandling::SjLj;
 423
 424   Options.NoInfsFPMath = CodeGenOpts.NoInfsFPMath;
 425   Options.NoNaNsFPMath = CodeGenOpts.NoNaNsFPMath;
 426   Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
 427   Options.UnsafeFPMath = CodeGenOpts.UnsafeFPMath;
 428   Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
 429   Options.FunctionSections = CodeGenOpts.FunctionSections;
 430   Options.DataSections = CodeGenOpts.DataSections;
 431   Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
 432   Options.EmulatedTLS = CodeGenOpts.EmulatedTLS;
 433   Options.DebuggerTuning = CodeGenOpts.getDebuggerTuning();
 434
 435   if (CodeGenOpts.EnableSplitDwarf)
 436     Options.MCOptions.SplitDwarfFile = CodeGenOpts.SplitDwarfFile;
 437   Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
 438   Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
 439   Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
 440   Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
 441   Options.MCOptions.MCIncrementalLinkerCompatible =
 442       CodeGenOpts.IncrementalLinkerCompatible;
 443   Options.MCOptions.MCPIECopyRelocations = CodeGenOpts.PIECopyRelocations;
 444   Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
 445   Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
 446   Options.MCOptions.PreserveAsmComments = CodeGenOpts.PreserveAsmComments;
 447   Options.MCOptions.ABIName = TargetOpts.ABI;
 448   for (const auto &Entry : HSOpts.UserEntries)
 449     if (!Entry.IsFramework &&
 450         (Entry.Group == frontend::IncludeDirGroup::Quoted ||
 451          Entry.Group == frontend::IncludeDirGroup::Angled ||
 452          Entry.Group == frontend::IncludeDirGroup::System))
 453       Options.MCOptions.IASSearchPaths.push_back(
 454           Entry.IgnoreSysRoot ? Entry.Path : HSOpts.Sysroot + Entry.Path);
 455 }
 456
 457 void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
 458                                       legacy::FunctionPassManager &FPM) {
 459   // Handle disabling of all LLVM passes, where we want to preserve the
 460   // internal module before any optimization.
 461   if (CodeGenOpts.DisableLLVMPasses)
 462     return;
 463
 464   // Figure out TargetLibraryInfo.  This needs to be added to MPM and FPM
 465   // manually (and not via PMBuilder), since some passes (eg. InstrProfiling)
 466   // are inserted before PMBuilder ones - they'd get the default-constructed
 467   // TLI with an unknown target otherwise.
 468   Triple TargetTriple(TheModule->getTargetTriple());
 469   std::unique_ptr<TargetLibraryInfoImpl> TLII(
 470       createTLII(TargetTriple, CodeGenOpts));
 471
 472   PassManagerBuilderWrapper PMBuilder(TargetTriple, CodeGenOpts, LangOpts);
 473
 474   // At O0 and O1 we only run the always inliner which is more efficient. At
 475   // higher optimization levels we run the normal inliner.
 476   if (CodeGenOpts.OptimizationLevel <= 1) {
 477     bool InsertLifetimeIntrinsics = (CodeGenOpts.OptimizationLevel != 0 &&
 478                                      !CodeGenOpts.DisableLifetimeMarkers);
 479     PMBuilder.Inliner = createAlwaysInlinerLegacyPass(InsertLifetimeIntrinsics);
 480   } else {
 481     // We do not want to inline hot callsites for SamplePGO module-summary build
 482     // because profile annotation will happen again in ThinLTO backend, and we
 483     // want the IR of the hot path to match the profile.
 484     PMBuilder.Inliner = createFunctionInliningPass(
 485         CodeGenOpts.OptimizationLevel, CodeGenOpts.OptimizeSize,
 486         (!CodeGenOpts.SampleProfileFile.empty() &&
 487          CodeGenOpts.EmitSummaryIndex));
 488   }
 489
 490   PMBuilder.OptLevel = CodeGenOpts.OptimizationLevel;
 491   PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
 492   PMBuilder.BBVectorize = CodeGenOpts.VectorizeBB;
 493   PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
 494   PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
 495
 496   PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
 497   PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
 498   PMBuilder.PrepareForThinLTO = CodeGenOpts.EmitSummaryIndex;
 499   PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
 500   PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
 501
 502   MPM.add(new TargetLibraryInfoWrapperPass(*TLII));
 503
 504   if (TM)
 505     TM->adjustPassManager(PMBuilder);
 506
 507   if (CodeGenOpts.DebugInfoForProfiling ||
 508       !CodeGenOpts.SampleProfileFile.empty())
 509     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
 510                            addAddDiscriminatorsPass);
 511
 512   // In ObjC ARC mode, add the main ARC optimization passes.
 513   if (LangOpts.ObjCAutoRefCount) {
 514     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
 515                            addObjCARCExpandPass);
 516     PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
 517                            addObjCARCAPElimPass);
 518     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
 519                            addObjCARCOptPass);
 520   }
 521
 522   if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds)) {
 523     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
 524                            addBoundsCheckingPass);
 525     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 526                            addBoundsCheckingPass);
 527   }
 528
 529   if (CodeGenOpts.SanitizeCoverageType ||
 530       CodeGenOpts.SanitizeCoverageIndirectCalls ||
 531       CodeGenOpts.SanitizeCoverageTraceCmp) {
 532     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 533                            addSanitizerCoveragePass);
 534     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 535                            addSanitizerCoveragePass);
 536   }
 537
 538   if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
 539     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 540                            addAddressSanitizerPasses);
 541     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 542                            addAddressSanitizerPasses);
 543   }
 544
 545   if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
 546     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 547                            addKernelAddressSanitizerPasses);
 548     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 549                            addKernelAddressSanitizerPasses);
 550   }
 551
 552   if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
 553     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 554                            addMemorySanitizerPass);
 555     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 556                            addMemorySanitizerPass);
 557   }
 558
 559   if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
 560     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 561                            addThreadSanitizerPass);
 562     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 563                            addThreadSanitizerPass);
 564   }
 565
 566   if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
 567     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 568                            addDataFlowSanitizerPass);
 569     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 570                            addDataFlowSanitizerPass);
 571   }
 572
 573   if (LangOpts.CoroutinesTS)
 574     addCoroutinePassesToExtensionPoints(PMBuilder);
 575
 576   if (LangOpts.Sanitize.hasOneOf(SanitizerKind::Efficiency)) {
 577     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 578                            addEfficiencySanitizerPass);
 579     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 580                            addEfficiencySanitizerPass);
 581   }
 582
 583   // Set up the per-function pass manager.
 584   FPM.add(new TargetLibraryInfoWrapperPass(*TLII));
 585   if (CodeGenOpts.VerifyModule)
 586     FPM.add(createVerifierPass());
 587
 588   // Set up the per-module pass manager.
 589   if (!CodeGenOpts.RewriteMapFiles.empty())
 590     addSymbolRewriterPass(CodeGenOpts, &MPM);
 591
 592   if (!CodeGenOpts.DisableGCov &&
 593       (CodeGenOpts.EmitGcovArcs || CodeGenOpts.EmitGcovNotes)) {
 594     // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
 595     // LLVM's -default-gcov-version flag is set to something invalid.
 596     GCOVOptions Options;
 597     Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
 598     Options.EmitData = CodeGenOpts.EmitGcovArcs;
 599     memcpy(Options.Version, CodeGenOpts.CoverageVersion, 4);
 600     Options.UseCfgChecksum = CodeGenOpts.CoverageExtraChecksum;
 601     Options.NoRedZone = CodeGenOpts.DisableRedZone;
 602     Options.FunctionNamesInData =
 603         !CodeGenOpts.CoverageNoFunctionNamesInData;
 604     Options.ExitBlockBeforeBody = CodeGenOpts.CoverageExitBlockBeforeBody;
 605     MPM.add(createGCOVProfilerPass(Options));
 606     if (CodeGenOpts.getDebugInfo() == codegenoptions::NoDebugInfo)
 607       MPM.add(createStripSymbolsPass(true));
 608   }
 609
 610   if (CodeGenOpts.hasProfileClangInstr()) {
 611     InstrProfOptions Options;
 612     Options.NoRedZone = CodeGenOpts.DisableRedZone;
 613     Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
 614     MPM.add(createInstrProfilingLegacyPass(Options));
 615   }
 616   if (CodeGenOpts.hasProfileIRInstr()) {
 617     PMBuilder.EnablePGOInstrGen = true;
 618     if (!CodeGenOpts.InstrProfileOutput.empty())
 619       PMBuilder.PGOInstrGen = CodeGenOpts.InstrProfileOutput;
 620     else
 621       PMBuilder.PGOInstrGen = DefaultProfileGenName;
 622   }
 623   if (CodeGenOpts.hasProfileIRUse())
 624     PMBuilder.PGOInstrUse = CodeGenOpts.ProfileInstrumentUsePath;
 625
 626   if (!CodeGenOpts.SampleProfileFile.empty())
 627     PMBuilder.PGOSampleUse = CodeGenOpts.SampleProfileFile;
 628
 629   PMBuilder.populateFunctionPassManager(FPM);
 630   PMBuilder.populateModulePassManager(MPM);
 631 }
 632
 633 static void setCommandLineOpts(const CodeGenOptions &CodeGenOpts) {
 634   SmallVector<const char *, 16> BackendArgs;
 635   BackendArgs.push_back("clang"); // Fake program name.
 636   if (!CodeGenOpts.DebugPass.empty()) {
 637     BackendArgs.push_back("-debug-pass");
 638     BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
 639   }
 640   if (!CodeGenOpts.LimitFloatPrecision.empty()) {
 641     BackendArgs.push_back("-limit-float-precision");
 642     BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
 643   }
 644   for (const std::string &BackendOption : CodeGenOpts.BackendOptions)
 645     BackendArgs.push_back(BackendOption.c_str());
 646   BackendArgs.push_back(nullptr);
 647   llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
 648                                     BackendArgs.data());
 649 }
 650
 651 void EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
 652   // Create the TargetMachine for generating code.
 653   std::string Error;
 654   std::string Triple = TheModule->getTargetTriple();
 655   const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
 656   if (!TheTarget) {
 657     if (MustCreateTM)
 658       Diags.Report(diag::err_fe_unable_to_create_target) << Error;
 659     return;
 660   }
 661
 662   llvm::CodeModel::Model CM  = getCodeModel(CodeGenOpts);
 663   std::string FeaturesStr =
 664       llvm::join(TargetOpts.Features.begin(), TargetOpts.Features.end(), ",");
 665   llvm::Reloc::Model RM = getRelocModel(CodeGenOpts);
 666   CodeGenOpt::Level OptLevel = getCGOptLevel(CodeGenOpts);
 667
 668   llvm::TargetOptions Options;
 669   initTargetOptions(Options, CodeGenOpts, TargetOpts, LangOpts, HSOpts);
 670   TM.reset(TheTarget->createTargetMachine(Triple, TargetOpts.CPU, FeaturesStr,
 671                                           Options, RM, CM, OptLevel));
 672 }
 673
 674 bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
 675                                        BackendAction Action,
 676                                        raw_pwrite_stream &OS) {
 677   // Add LibraryInfo.
 678   llvm::Triple TargetTriple(TheModule->getTargetTriple());
 679   std::unique_ptr<TargetLibraryInfoImpl> TLII(
 680       createTLII(TargetTriple, CodeGenOpts));
 681   CodeGenPasses.add(new TargetLibraryInfoWrapperPass(*TLII));
 682
 683   // Normal mode, emit a .s or .o file by running the code generator. Note,
 684   // this also adds codegenerator level optimization passes.
 685   TargetMachine::CodeGenFileType CGFT = getCodeGenFileType(Action);
 686
 687   // Add ObjC ARC final-cleanup optimizations. This is done as part of the
 688   // "codegen" passes so that it isn't run multiple times when there is
 689   // inlining happening.
 690   if (CodeGenOpts.OptimizationLevel > 0)
 691     CodeGenPasses.add(createObjCARCContractPass());
 692
 693   if (TM->addPassesToEmitFile(CodeGenPasses, OS, CGFT,
 694                               /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
 695     Diags.Report(diag::err_fe_unable_to_interface_with_target);
 696     return false;
 697   }
 698
 699   return true;
 700 }
 701
 702 void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
 703                                       std::unique_ptr<raw_pwrite_stream> OS) {
 704   TimeRegion Region(llvm::TimePassesIsEnabled ? &CodeGenerationTime : nullptr);
 705
 706   setCommandLineOpts(CodeGenOpts);
 707
 708   bool UsesCodeGen = (Action != Backend_EmitNothing &&
 709                       Action != Backend_EmitBC &&
 710                       Action != Backend_EmitLL);
 711   CreateTargetMachine(UsesCodeGen);
 712
 713   if (UsesCodeGen && !TM)
 714     return;
 715   if (TM)
 716     TheModule->setDataLayout(TM->createDataLayout());
 717
 718   legacy::PassManager PerModulePasses;
 719   PerModulePasses.add(
 720       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
 721
 722   legacy::FunctionPassManager PerFunctionPasses(TheModule);
 723   PerFunctionPasses.add(
 724       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
 725
 726   CreatePasses(PerModulePasses, PerFunctionPasses);
 727
 728   legacy::PassManager CodeGenPasses;
 729   CodeGenPasses.add(
 730       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
 731
 732   std::unique_ptr<raw_fd_ostream> ThinLinkOS;
 733
 734   switch (Action) {
 735   case Backend_EmitNothing:
 736     break;
 737
 738   case Backend_EmitBC:
 739     if (CodeGenOpts.EmitSummaryIndex) {
 740       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
 741         std::error_code EC;
 742         ThinLinkOS.reset(new llvm::raw_fd_ostream(
 743             CodeGenOpts.ThinLinkBitcodeFile, EC,
 744             llvm::sys::fs::F_None));
 745         if (EC) {
 746           Diags.Report(diag::err_fe_unable_to_open_output) << CodeGenOpts.ThinLinkBitcodeFile
 747                                                            << EC.message();
 748           return;
 749         }
 750       }
 751       PerModulePasses.add(
 752           createWriteThinLTOBitcodePass(*OS, ThinLinkOS.get()));
 753     }
 754     else
 755       PerModulePasses.add(
 756           createBitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists));
 757     break;
 758
 759   case Backend_EmitLL:
 760     PerModulePasses.add(
 761         createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
 762     break;
 763
 764   default:
 765     if (!AddEmitPasses(CodeGenPasses, Action, *OS))
 766       return;
 767   }
 768
 769   // Before executing passes, print the final values of the LLVM options.
 770   cl::PrintOptionValues();
 771
 772   // Run passes. For now we do all passes at once, but eventually we
 773   // would like to have the option of streaming code generation.
 774
 775   {
 776     PrettyStackTraceString CrashInfo("Per-function optimization");
 777
 778     PerFunctionPasses.doInitialization();
 779     for (Function &F : *TheModule)
 780       if (!F.isDeclaration())
 781         PerFunctionPasses.run(F);
 782     PerFunctionPasses.doFinalization();
 783   }
 784
 785   {
 786     PrettyStackTraceString CrashInfo("Per-module optimization passes");
 787     PerModulePasses.run(*TheModule);
 788   }
 789
 790   {
 791     PrettyStackTraceString CrashInfo("Code generation");
 792     CodeGenPasses.run(*TheModule);
 793   }
 794 }
 795
 796 static PassBuilder::OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
 797   switch (Opts.OptimizationLevel) {
 798   default:
 799     llvm_unreachable("Invalid optimization level!");
 800
 801   case 1:
 802     return PassBuilder::O1;
 803
 804   case 2:
 805     switch (Opts.OptimizeSize) {
 806     default:
 807       llvm_unreachable("Invalide optimization level for size!");
 808
 809     case 0:
 810       return PassBuilder::O2;
 811
 812     case 1:
 813       return PassBuilder::Os;
 814
 815     case 2:
 816       return PassBuilder::Oz;
 817     }
 818
 819   case 3:
 820     return PassBuilder::O3;
 821   }
 822 }
 823
 824 /// A clean version of `EmitAssembly` that uses the new pass manager.
 825 ///
 826 /// Not all features are currently supported in this system, but where
 827 /// necessary it falls back to the legacy pass manager to at least provide
 828 /// basic functionality.
 829 ///
 830 /// This API is planned to have its functionality finished and then to replace
 831 /// `EmitAssembly` at some point in the future when the default switches.
 832 void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
 833     BackendAction Action, std::unique_ptr<raw_pwrite_stream> OS) {
 834   TimeRegion Region(llvm::TimePassesIsEnabled ? &CodeGenerationTime : nullptr);
 835   setCommandLineOpts(CodeGenOpts);
 836
 837   // The new pass manager always makes a target machine available to passes
 838   // during construction.
 839   CreateTargetMachine(/*MustCreateTM*/ true);
 840   if (!TM)
 841     // This will already be diagnosed, just bail.
 842     return;
 843   TheModule->setDataLayout(TM->createDataLayout());
 844
 845   PGOOptions PGOOpt;
 846
 847   // -fprofile-generate.
 848   PGOOpt.RunProfileGen = CodeGenOpts.hasProfileIRInstr();
 849   if (PGOOpt.RunProfileGen)
 850     PGOOpt.ProfileGenFile = CodeGenOpts.InstrProfileOutput.empty() ?
 851       DefaultProfileGenName : CodeGenOpts.InstrProfileOutput;
 852
 853   // -fprofile-use.
 854   if (CodeGenOpts.hasProfileIRUse())
 855     PGOOpt.ProfileUseFile = CodeGenOpts.ProfileInstrumentUsePath;
 856
 857   // Only pass a PGO options struct if -fprofile-generate or
 858   // -fprofile-use were passed on the cmdline.
 859   PassBuilder PB(TM.get(),
 860     (PGOOpt.RunProfileGen ||
 861       !PGOOpt.ProfileUseFile.empty()) ?
 862         Optional<PGOOptions>(PGOOpt) : None);
 863
 864   LoopAnalysisManager LAM;
 865   FunctionAnalysisManager FAM;
 866   CGSCCAnalysisManager CGAM;
 867   ModuleAnalysisManager MAM;
 868
 869   // Register the AA manager first so that our version is the one used.
 870   FAM.registerPass([&] { return PB.buildDefaultAAPipeline(); });
 871
 872   // Register all the basic analyses with the managers.
 873   PB.registerModuleAnalyses(MAM);
 874   PB.registerCGSCCAnalyses(CGAM);
 875   PB.registerFunctionAnalyses(FAM);
 876   PB.registerLoopAnalyses(LAM);
 877   PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
 878
 879   ModulePassManager MPM;
 880
 881   if (!CodeGenOpts.DisableLLVMPasses) {
 882     if (CodeGenOpts.OptimizationLevel == 0) {
 883       // Build a minimal pipeline based on the semantics required by Clang,
 884       // which is just that always inlining occurs.
 885       MPM.addPass(AlwaysInlinerPass());
 886     } else {
 887       // Otherwise, use the default pass pipeline. We also have to map our
 888       // optimization levels into one of the distinct levels used to configure
 889       // the pipeline.
 890       PassBuilder::OptimizationLevel Level = mapToLevel(CodeGenOpts);
 891
 892       MPM = PB.buildPerModuleDefaultPipeline(Level);
 893     }
 894   }
 895
 896   // FIXME: We still use the legacy pass manager to do code generation. We
 897   // create that pass manager here and use it as needed below.
 898   legacy::PassManager CodeGenPasses;
 899   bool NeedCodeGen = false;
 900
 901   // Append any output we need to the pass manager.
 902   switch (Action) {
 903   case Backend_EmitNothing:
 904     break;
 905
 906   case Backend_EmitBC:
 907     MPM.addPass(BitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists,
 908                                   CodeGenOpts.EmitSummaryIndex,
 909                                   CodeGenOpts.EmitSummaryIndex));
 910     break;
 911
 912   case Backend_EmitLL:
 913     MPM.addPass(PrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
 914     break;
 915
 916   case Backend_EmitAssembly:
 917   case Backend_EmitMCNull:
 918   case Backend_EmitObj:
 919     NeedCodeGen = true;
 920     CodeGenPasses.add(
 921         createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
 922     if (!AddEmitPasses(CodeGenPasses, Action, *OS))
 923       // FIXME: Should we handle this error differently?
 924       return;
 925     break;
 926   }
 927
 928   // Before executing passes, print the final values of the LLVM options.
 929   cl::PrintOptionValues();
 930
 931   // Now that we have all of the passes ready, run them.
 932   {
 933     PrettyStackTraceString CrashInfo("Optimizer");
 934     MPM.run(*TheModule, MAM);
 935   }
 936
 937   // Now if needed, run the legacy PM for codegen.
 938   if (NeedCodeGen) {
 939     PrettyStackTraceString CrashInfo("Code generation");
 940     CodeGenPasses.run(*TheModule);
 941   }
 942 }
 943
 944 Expected<BitcodeModule> clang::FindThinLTOModule(MemoryBufferRef MBRef) {
 945   Expected<std::vector<BitcodeModule>> BMsOrErr = getBitcodeModuleList(MBRef);
 946   if (!BMsOrErr)
 947     return BMsOrErr.takeError();
 948
 949   // The bitcode file may contain multiple modules, we want the one with a
 950   // summary.
 951   for (BitcodeModule &BM : *BMsOrErr) {
 952     Expected<bool> HasSummary = BM.hasSummary();
 953     if (HasSummary && *HasSummary)
 954       return BM;
 955   }
 956
 957   return make_error<StringError>("Could not find module summary",
 958                                  inconvertibleErrorCode());
 959 }
 960
 961 static void runThinLTOBackend(ModuleSummaryIndex *CombinedIndex, Module *M,
 962                               const HeaderSearchOptions &HeaderOpts,
 963                               const CodeGenOptions &CGOpts,
 964                               const clang::TargetOptions &TOpts,
 965                               const LangOptions &LOpts,
 966                               std::unique_ptr<raw_pwrite_stream> OS,
 967                               std::string SampleProfile,
 968                               BackendAction Action) {
 969   StringMap<std::map<GlobalValue::GUID, GlobalValueSummary *>>
 970       ModuleToDefinedGVSummaries;
 971   CombinedIndex->collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries);
 972
 973   setCommandLineOpts(CGOpts);
 974
 975   // We can simply import the values mentioned in the combined index, since
 976   // we should only invoke this using the individual indexes written out
 977   // via a WriteIndexesThinBackend.
 978   FunctionImporter::ImportMapTy ImportList;
 979   for (auto &GlobalList : *CombinedIndex) {
 980     // Ignore entries for undefined references.
 981     if (GlobalList.second.SummaryList.empty())
 982       continue;
 983
 984     auto GUID = GlobalList.first;
 985     assert(GlobalList.second.SummaryList.size() == 1 &&
 986            "Expected individual combined index to have one summary per GUID");
 987     auto &Summary = GlobalList.second.SummaryList[0];
 988     // Skip the summaries for the importing module. These are included to
 989     // e.g. record required linkage changes.
 990     if (Summary->modulePath() == M->getModuleIdentifier())
 991       continue;
 992     // Doesn't matter what value we plug in to the map, just needs an entry
 993     // to provoke importing by thinBackend.
 994     ImportList[Summary->modulePath()][GUID] = 1;
 995   }
 996
 997   std::vector<std::unique_ptr<llvm::MemoryBuffer>> OwnedImports;
 998   MapVector<llvm::StringRef, llvm::BitcodeModule> ModuleMap;
 999
1000   for (auto &I : ImportList) {
1001     ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> MBOrErr =
1002         llvm::MemoryBuffer::getFile(I.first());
1003     if (!MBOrErr) {
1004       errs() << "Error loading imported file '" << I.first()
1005              << "': " << MBOrErr.getError().message() << "\n";
1006       return;
1007     }
1008
1009     Expected<BitcodeModule> BMOrErr = FindThinLTOModule(**MBOrErr);
1010     if (!BMOrErr) {
1011       handleAllErrors(BMOrErr.takeError(), [&](ErrorInfoBase &EIB) {
1012         errs() << "Error loading imported file '" << I.first()
1013                << "': " << EIB.message() << '\n';
1014       });
1015       return;
1016     }
1017     ModuleMap.insert({I.first(), *BMOrErr});
1018
1019     OwnedImports.push_back(std::move(*MBOrErr));
1020   }
1021   auto AddStream = [&](size_t Task) {
1022     return llvm::make_unique<lto::NativeObjectStream>(std::move(OS));
1023   };
1024   lto::Config Conf;
1025   Conf.CPU = TOpts.CPU;
1026   Conf.CodeModel = getCodeModel(CGOpts);
1027   Conf.MAttrs = TOpts.Features;
1028   Conf.RelocModel = getRelocModel(CGOpts);
1029   Conf.CGOptLevel = getCGOptLevel(CGOpts);
1030   initTargetOptions(Conf.Options, CGOpts, TOpts, LOpts, HeaderOpts);
1031   Conf.SampleProfile = std::move(SampleProfile);
1032   switch (Action) {
1033   case Backend_EmitNothing:
1034     Conf.PreCodeGenModuleHook = [](size_t Task, const Module &Mod) {
1035       return false;
1036     };
1037     break;
1038   case Backend_EmitLL:
1039     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1040       M->print(*OS, nullptr, CGOpts.EmitLLVMUseLists);
1041       return false;
1042     };
1043     break;
1044   case Backend_EmitBC:
1045     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1046       WriteBitcodeToFile(M, *OS, CGOpts.EmitLLVMUseLists);
1047       return false;
1048     };
1049     break;
1050   default:
1051     Conf.CGFileType = getCodeGenFileType(Action);
1052     break;
1053   }
1054   if (Error E = thinBackend(
1055           Conf, 0, AddStream, *M, *CombinedIndex, ImportList,
1056           ModuleToDefinedGVSummaries[M->getModuleIdentifier()], ModuleMap)) {
1057     handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1058       errs() << "Error running ThinLTO backend: " << EIB.message() << '\n';
1059     });
1060   }
1061 }
1062
1063 void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
1064                               const HeaderSearchOptions &HeaderOpts,
1065                               const CodeGenOptions &CGOpts,
1066                               const clang::TargetOptions &TOpts,
1067                               const LangOptions &LOpts,
1068                               const llvm::DataLayout &TDesc, Module *M,
1069                               BackendAction Action,
1070                               std::unique_ptr<raw_pwrite_stream> OS) {
1071   if (!CGOpts.ThinLTOIndexFile.empty()) {
1072     // If we are performing a ThinLTO importing compile, load the function index
1073     // into memory and pass it into runThinLTOBackend, which will run the
1074     // function importer and invoke LTO passes.
1075     Expected<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
1076         llvm::getModuleSummaryIndexForFile(CGOpts.ThinLTOIndexFile);
1077     if (!IndexOrErr) {
1078       logAllUnhandledErrors(IndexOrErr.takeError(), errs(),
1079                             "Error loading index file '" +
1080                             CGOpts.ThinLTOIndexFile + "': ");
1081       return;
1082     }
1083     std::unique_ptr<ModuleSummaryIndex> CombinedIndex = std::move(*IndexOrErr);
1084     // A null CombinedIndex means we should skip ThinLTO compilation
1085     // (LLVM will optionally ignore empty index files, returning null instead
1086     // of an error).
1087     bool DoThinLTOBackend = CombinedIndex != nullptr;
1088     if (DoThinLTOBackend) {
1089       runThinLTOBackend(CombinedIndex.get(), M, HeaderOpts, CGOpts, TOpts,
1090                         LOpts, std::move(OS), CGOpts.SampleProfileFile, Action);
1091       return;
1092     }
1093   }
1094
1095   EmitAssemblyHelper AsmHelper(Diags, HeaderOpts, CGOpts, TOpts, LOpts, M);
1096
1097   if (CGOpts.ExperimentalNewPassManager)
1098     AsmHelper.EmitAssemblyWithNewPassManager(Action, std::move(OS));
1099   else
1100     AsmHelper.EmitAssembly(Action, std::move(OS));
1101
1102   // Verify clang's TargetInfo DataLayout against the LLVM TargetMachine's
1103   // DataLayout.
1104   if (AsmHelper.TM) {
1105     std::string DLDesc = M->getDataLayout().getStringRepresentation();
1106     if (DLDesc != TDesc.getStringRepresentation()) {
1107       unsigned DiagID = Diags.getCustomDiagID(
1108           DiagnosticsEngine::Error, "backend data layout '%0' does not match "
1109                                     "expected target description '%1'");
1110       Diags.Report(DiagID) << DLDesc << TDesc.getStringRepresentation();
1111     }
1112   }
1113 }
1114
1115 static const char* getSectionNameForBitcode(const Triple &T) {
1116   switch (T.getObjectFormat()) {
1117   case Triple::MachO:
1118     return "__LLVM,__bitcode";
1119   case Triple::COFF:
1120   case Triple::ELF:
1121   case Triple::Wasm:
1122   case Triple::UnknownObjectFormat:
1123     return ".llvmbc";
1124   }
1125   llvm_unreachable("Unimplemented ObjectFormatType");
1126 }
1127
1128 static const char* getSectionNameForCommandline(const Triple &T) {
1129   switch (T.getObjectFormat()) {
1130   case Triple::MachO:
1131     return "__LLVM,__cmdline";
1132   case Triple::COFF:
1133   case Triple::ELF:
1134   case Triple::Wasm:
1135   case Triple::UnknownObjectFormat:
1136     return ".llvmcmd";
1137   }
1138   llvm_unreachable("Unimplemented ObjectFormatType");
1139 }
1140
1141 // With -fembed-bitcode, save a copy of the llvm IR as data in the
1142 // __LLVM,__bitcode section.
1143 void clang::EmbedBitcode(llvm::Module *M, const CodeGenOptions &CGOpts,
1144                          llvm::MemoryBufferRef Buf) {
1145   if (CGOpts.getEmbedBitcode() == CodeGenOptions::Embed_Off)
1146     return;
1147
1148   // Save llvm.compiler.used and remote it.
1149   SmallVector<Constant*, 2> UsedArray;
1150   SmallSet<GlobalValue*, 4> UsedGlobals;
1151   Type *UsedElementType = Type::getInt8Ty(M->getContext())->getPointerTo(0);
1152   GlobalVariable *Used = collectUsedGlobalVariables(*M, UsedGlobals, true);
1153   for (auto *GV : UsedGlobals) {
1154     if (GV->getName() != "llvm.embedded.module" &&
1155         GV->getName() != "llvm.cmdline")
1156       UsedArray.push_back(
1157           ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
1158   }
1159   if (Used)
1160     Used->eraseFromParent();
1161
1162   // Embed the bitcode for the llvm module.
1163   std::string Data;
1164   ArrayRef<uint8_t> ModuleData;
1165   Triple T(M->getTargetTriple());
1166   // Create a constant that contains the bitcode.
1167   // In case of embedding a marker, ignore the input Buf and use the empty
1168   // ArrayRef. It is also legal to create a bitcode marker even Buf is empty.
1169   if (CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Marker) {
1170     if (!isBitcode((const unsigned char *)Buf.getBufferStart(),
1171                    (const unsigned char *)Buf.getBufferEnd())) {
1172       // If the input is LLVM Assembly, bitcode is produced by serializing
1173       // the module. Use-lists order need to be perserved in this case.
1174       llvm::raw_string_ostream OS(Data);
1175       llvm::WriteBitcodeToFile(M, OS, /* ShouldPreserveUseListOrder */ true);
1176       ModuleData =
1177           ArrayRef<uint8_t>((const uint8_t *)OS.str().data(), OS.str().size());
1178     } else
1179       // If the input is LLVM bitcode, write the input byte stream directly.
1180       ModuleData = ArrayRef<uint8_t>((const uint8_t *)Buf.getBufferStart(),
1181                                      Buf.getBufferSize());
1182   }
1183   llvm::Constant *ModuleConstant =
1184       llvm::ConstantDataArray::get(M->getContext(), ModuleData);
1185   llvm::GlobalVariable *GV = new llvm::GlobalVariable(
1186       *M, ModuleConstant->getType(), true, llvm::GlobalValue::PrivateLinkage,
1187       ModuleConstant);
1188   GV->setSection(getSectionNameForBitcode(T));
1189   UsedArray.push_back(
1190       ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
1191   if (llvm::GlobalVariable *Old =
1192           M->getGlobalVariable("llvm.embedded.module", true)) {
1193     assert(Old->hasOneUse() &&
1194            "llvm.embedded.module can only be used once in llvm.compiler.used");
1195     GV->takeName(Old);
1196     Old->eraseFromParent();
1197   } else {
1198     GV->setName("llvm.embedded.module");
1199   }
1200
1201   // Skip if only bitcode needs to be embedded.
1202   if (CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Bitcode) {
1203     // Embed command-line options.
1204     ArrayRef<uint8_t> CmdData(const_cast<uint8_t *>(CGOpts.CmdArgs.data()),
1205                               CGOpts.CmdArgs.size());
1206     llvm::Constant *CmdConstant =
1207       llvm::ConstantDataArray::get(M->getContext(), CmdData);
1208     GV = new llvm::GlobalVariable(*M, CmdConstant->getType(), true,
1209                                   llvm::GlobalValue::PrivateLinkage,
1210                                   CmdConstant);
1211     GV->setSection(getSectionNameForCommandline(T));
1212     UsedArray.push_back(
1213         ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
1214     if (llvm::GlobalVariable *Old =
1215             M->getGlobalVariable("llvm.cmdline", true)) {
1216       assert(Old->hasOneUse() &&
1217              "llvm.cmdline can only be used once in llvm.compiler.used");
1218       GV->takeName(Old);
1219       Old->eraseFromParent();
1220     } else {
1221       GV->setName("llvm.cmdline");
1222     }
1223   }
1224
1225   if (UsedArray.empty())
1226     return;
1227
1228   // Recreate llvm.compiler.used.
1229   ArrayType *ATy = ArrayType::get(UsedElementType, UsedArray.size());
1230   auto *NewUsed = new GlobalVariable(
1231       *M, ATy, false, llvm::GlobalValue::AppendingLinkage,
1232       llvm::ConstantArray::get(ATy, UsedArray), "llvm.compiler.used");
1233   NewUsed->setSection("llvm.metadata");
1234 }