contrib/llvm/tools/clang/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/CodeGen/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/IPO/ThinLTOBitcodeWriter.h"
  53 #include "llvm/Transforms/Instrumentation.h"
  54 #include "llvm/Transforms/Instrumentation/BoundsChecking.h"
  55 #include "llvm/Transforms/ObjCARC.h"
  56 #include "llvm/Transforms/Scalar.h"
  57 #include "llvm/Transforms/Scalar/GVN.h"
  58 #include "llvm/Transforms/Utils/NameAnonGlobals.h"
  59 #include "llvm/Transforms/Utils/SymbolRewriter.h"
  60 #include <memory>
  61 using namespace clang;
  62 using namespace llvm;
  63
  64 namespace {
  65
  66 // Default filename used for profile generation.
  67 static constexpr StringLiteral DefaultProfileGenName = "default_%m.profraw";
  68
  69 class EmitAssemblyHelper {
  70   DiagnosticsEngine &Diags;
  71   const HeaderSearchOptions &HSOpts;
  72   const CodeGenOptions &CodeGenOpts;
  73   const clang::TargetOptions &TargetOpts;
  74   const LangOptions &LangOpts;
  75   Module *TheModule;
  76
  77   Timer CodeGenerationTime;
  78
  79   std::unique_ptr<raw_pwrite_stream> OS;
  80
  81   TargetIRAnalysis getTargetIRAnalysis() const {
  82     if (TM)
  83       return TM->getTargetIRAnalysis();
  84
  85     return TargetIRAnalysis();
  86   }
  87
  88   void CreatePasses(legacy::PassManager &MPM, legacy::FunctionPassManager &FPM);
  89
  90   /// Generates the TargetMachine.
  91   /// Leaves TM unchanged if it is unable to create the target machine.
  92   /// Some of our clang tests specify triples which are not built
  93   /// into clang. This is okay because these tests check the generated
  94   /// IR, and they require DataLayout which depends on the triple.
  95   /// In this case, we allow this method to fail and not report an error.
  96   /// When MustCreateTM is used, we print an error if we are unable to load
  97   /// the requested target.
  98   void CreateTargetMachine(bool MustCreateTM);
  99
 100   /// Add passes necessary to emit assembly or LLVM IR.
 101   ///
 102   /// \return True on success.
 103   bool AddEmitPasses(legacy::PassManager &CodeGenPasses, BackendAction Action,
 104                      raw_pwrite_stream &OS);
 105
 106 public:
 107   EmitAssemblyHelper(DiagnosticsEngine &_Diags,
 108                      const HeaderSearchOptions &HeaderSearchOpts,
 109                      const CodeGenOptions &CGOpts,
 110                      const clang::TargetOptions &TOpts,
 111                      const LangOptions &LOpts, Module *M)
 112       : Diags(_Diags), HSOpts(HeaderSearchOpts), CodeGenOpts(CGOpts),
 113         TargetOpts(TOpts), LangOpts(LOpts), TheModule(M),
 114         CodeGenerationTime("codegen", "Code Generation Time") {}
 115
 116   ~EmitAssemblyHelper() {
 117     if (CodeGenOpts.DisableFree)
 118       BuryPointer(std::move(TM));
 119   }
 120
 121   std::unique_ptr<TargetMachine> TM;
 122
 123   void EmitAssembly(BackendAction Action,
 124                     std::unique_ptr<raw_pwrite_stream> OS);
 125
 126   void EmitAssemblyWithNewPassManager(BackendAction Action,
 127                                       std::unique_ptr<raw_pwrite_stream> OS);
 128 };
 129
 130 // We need this wrapper to access LangOpts and CGOpts from extension functions
 131 // that we add to the PassManagerBuilder.
 132 class PassManagerBuilderWrapper : public PassManagerBuilder {
 133 public:
 134   PassManagerBuilderWrapper(const Triple &TargetTriple,
 135                             const CodeGenOptions &CGOpts,
 136                             const LangOptions &LangOpts)
 137       : PassManagerBuilder(), TargetTriple(TargetTriple), CGOpts(CGOpts),
 138         LangOpts(LangOpts) {}
 139   const Triple &getTargetTriple() const { return TargetTriple; }
 140   const CodeGenOptions &getCGOpts() const { return CGOpts; }
 141   const LangOptions &getLangOpts() const { return LangOpts; }
 142
 143 private:
 144   const Triple &TargetTriple;
 145   const CodeGenOptions &CGOpts;
 146   const LangOptions &LangOpts;
 147 };
 148 }
 149
 150 static void addObjCARCAPElimPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
 151   if (Builder.OptLevel > 0)
 152     PM.add(createObjCARCAPElimPass());
 153 }
 154
 155 static void addObjCARCExpandPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
 156   if (Builder.OptLevel > 0)
 157     PM.add(createObjCARCExpandPass());
 158 }
 159
 160 static void addObjCARCOptPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
 161   if (Builder.OptLevel > 0)
 162     PM.add(createObjCARCOptPass());
 163 }
 164
 165 static void addAddDiscriminatorsPass(const PassManagerBuilder &Builder,
 166                                      legacy::PassManagerBase &PM) {
 167   PM.add(createAddDiscriminatorsPass());
 168 }
 169
 170 static void addBoundsCheckingPass(const PassManagerBuilder &Builder,
 171                                   legacy::PassManagerBase &PM) {
 172   PM.add(createBoundsCheckingLegacyPass());
 173 }
 174
 175 static void addSanitizerCoveragePass(const PassManagerBuilder &Builder,
 176                                      legacy::PassManagerBase &PM) {
 177   const PassManagerBuilderWrapper &BuilderWrapper =
 178       static_cast<const PassManagerBuilderWrapper&>(Builder);
 179   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
 180   SanitizerCoverageOptions Opts;
 181   Opts.CoverageType =
 182       static_cast<SanitizerCoverageOptions::Type>(CGOpts.SanitizeCoverageType);
 183   Opts.IndirectCalls = CGOpts.SanitizeCoverageIndirectCalls;
 184   Opts.TraceBB = CGOpts.SanitizeCoverageTraceBB;
 185   Opts.TraceCmp = CGOpts.SanitizeCoverageTraceCmp;
 186   Opts.TraceDiv = CGOpts.SanitizeCoverageTraceDiv;
 187   Opts.TraceGep = CGOpts.SanitizeCoverageTraceGep;
 188   Opts.Use8bitCounters = CGOpts.SanitizeCoverage8bitCounters;
 189   Opts.TracePC = CGOpts.SanitizeCoverageTracePC;
 190   Opts.TracePCGuard = CGOpts.SanitizeCoverageTracePCGuard;
 191   Opts.NoPrune = CGOpts.SanitizeCoverageNoPrune;
 192   Opts.Inline8bitCounters = CGOpts.SanitizeCoverageInline8bitCounters;
 193   Opts.PCTable = CGOpts.SanitizeCoveragePCTable;
 194   Opts.StackDepth = CGOpts.SanitizeCoverageStackDepth;
 195   PM.add(createSanitizerCoverageModulePass(Opts));
 196 }
 197
 198 // Check if ASan should use GC-friendly instrumentation for globals.
 199 // First of all, there is no point if -fdata-sections is off (expect for MachO,
 200 // where this is not a factor). Also, on ELF this feature requires an assembler
 201 // extension that only works with -integrated-as at the moment.
 202 static bool asanUseGlobalsGC(const Triple &T, const CodeGenOptions &CGOpts) {
 203   if (!CGOpts.SanitizeAddressGlobalsDeadStripping)
 204     return false;
 205   switch (T.getObjectFormat()) {
 206   case Triple::MachO:
 207   case Triple::COFF:
 208     return true;
 209   case Triple::ELF:
 210     return CGOpts.DataSections && !CGOpts.DisableIntegratedAS;
 211   default:
 212     return false;
 213   }
 214 }
 215
 216 static void addAddressSanitizerPasses(const PassManagerBuilder &Builder,
 217                                       legacy::PassManagerBase &PM) {
 218   const PassManagerBuilderWrapper &BuilderWrapper =
 219       static_cast<const PassManagerBuilderWrapper&>(Builder);
 220   const Triple &T = BuilderWrapper.getTargetTriple();
 221   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
 222   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Address);
 223   bool UseAfterScope = CGOpts.SanitizeAddressUseAfterScope;
 224   bool UseGlobalsGC = asanUseGlobalsGC(T, CGOpts);
 225   PM.add(createAddressSanitizerFunctionPass(/*CompileKernel*/ false, Recover,
 226                                             UseAfterScope));
 227   PM.add(createAddressSanitizerModulePass(/*CompileKernel*/ false, Recover,
 228                                           UseGlobalsGC));
 229 }
 230
 231 static void addKernelAddressSanitizerPasses(const PassManagerBuilder &Builder,
 232                                             legacy::PassManagerBase &PM) {
 233   PM.add(createAddressSanitizerFunctionPass(
 234       /*CompileKernel*/ true,
 235       /*Recover*/ true, /*UseAfterScope*/ false));
 236   PM.add(createAddressSanitizerModulePass(/*CompileKernel*/true,
 237                                           /*Recover*/true));
 238 }
 239
 240 static void addHWAddressSanitizerPasses(const PassManagerBuilder &Builder,
 241                                             legacy::PassManagerBase &PM) {
 242   const PassManagerBuilderWrapper &BuilderWrapper =
 243       static_cast<const PassManagerBuilderWrapper &>(Builder);
 244   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
 245   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::HWAddress);
 246   PM.add(createHWAddressSanitizerPass(Recover));
 247 }
 248
 249 static void addMemorySanitizerPass(const PassManagerBuilder &Builder,
 250                                    legacy::PassManagerBase &PM) {
 251   const PassManagerBuilderWrapper &BuilderWrapper =
 252       static_cast<const PassManagerBuilderWrapper&>(Builder);
 253   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
 254   int TrackOrigins = CGOpts.SanitizeMemoryTrackOrigins;
 255   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Memory);
 256   PM.add(createMemorySanitizerPass(TrackOrigins, Recover));
 257
 258   // MemorySanitizer inserts complex instrumentation that mostly follows
 259   // the logic of the original code, but operates on "shadow" values.
 260   // It can benefit from re-running some general purpose optimization passes.
 261   if (Builder.OptLevel > 0) {
 262     PM.add(createEarlyCSEPass());
 263     PM.add(createReassociatePass());
 264     PM.add(createLICMPass());
 265     PM.add(createGVNPass());
 266     PM.add(createInstructionCombiningPass());
 267     PM.add(createDeadStoreEliminationPass());
 268   }
 269 }
 270
 271 static void addThreadSanitizerPass(const PassManagerBuilder &Builder,
 272                                    legacy::PassManagerBase &PM) {
 273   PM.add(createThreadSanitizerPass());
 274 }
 275
 276 static void addDataFlowSanitizerPass(const PassManagerBuilder &Builder,
 277                                      legacy::PassManagerBase &PM) {
 278   const PassManagerBuilderWrapper &BuilderWrapper =
 279       static_cast<const PassManagerBuilderWrapper&>(Builder);
 280   const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
 281   PM.add(createDataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
 282 }
 283
 284 static void addEfficiencySanitizerPass(const PassManagerBuilder &Builder,
 285                                        legacy::PassManagerBase &PM) {
 286   const PassManagerBuilderWrapper &BuilderWrapper =
 287       static_cast<const PassManagerBuilderWrapper&>(Builder);
 288   const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
 289   EfficiencySanitizerOptions Opts;
 290   if (LangOpts.Sanitize.has(SanitizerKind::EfficiencyCacheFrag))
 291     Opts.ToolType = EfficiencySanitizerOptions::ESAN_CacheFrag;
 292   else if (LangOpts.Sanitize.has(SanitizerKind::EfficiencyWorkingSet))
 293     Opts.ToolType = EfficiencySanitizerOptions::ESAN_WorkingSet;
 294   PM.add(createEfficiencySanitizerPass(Opts));
 295 }
 296
 297 static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
 298                                          const CodeGenOptions &CodeGenOpts) {
 299   TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple);
 300   if (!CodeGenOpts.SimplifyLibCalls)
 301     TLII->disableAllFunctions();
 302   else {
 303     // Disable individual libc/libm calls in TargetLibraryInfo.
 304     LibFunc F;
 305     for (auto &FuncName : CodeGenOpts.getNoBuiltinFuncs())
 306       if (TLII->getLibFunc(FuncName, F))
 307         TLII->setUnavailable(F);
 308   }
 309
 310   switch (CodeGenOpts.getVecLib()) {
 311   case CodeGenOptions::Accelerate:
 312     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::Accelerate);
 313     break;
 314   case CodeGenOptions::SVML:
 315     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::SVML);
 316     break;
 317   default:
 318     break;
 319   }
 320   return TLII;
 321 }
 322
 323 static void addSymbolRewriterPass(const CodeGenOptions &Opts,
 324                                   legacy::PassManager *MPM) {
 325   llvm::SymbolRewriter::RewriteDescriptorList DL;
 326
 327   llvm::SymbolRewriter::RewriteMapParser MapParser;
 328   for (const auto &MapFile : Opts.RewriteMapFiles)
 329     MapParser.parse(MapFile, &DL);
 330
 331   MPM->add(createRewriteSymbolsPass(DL));
 332 }
 333
 334 static CodeGenOpt::Level getCGOptLevel(const CodeGenOptions &CodeGenOpts) {
 335   switch (CodeGenOpts.OptimizationLevel) {
 336   default:
 337     llvm_unreachable("Invalid optimization level!");
 338   case 0:
 339     return CodeGenOpt::None;
 340   case 1:
 341     return CodeGenOpt::Less;
 342   case 2:
 343     return CodeGenOpt::Default; // O2/Os/Oz
 344   case 3:
 345     return CodeGenOpt::Aggressive;
 346   }
 347 }
 348
 349 static Optional<llvm::CodeModel::Model>
 350 getCodeModel(const CodeGenOptions &CodeGenOpts) {
 351   unsigned CodeModel = llvm::StringSwitch<unsigned>(CodeGenOpts.CodeModel)
 352                            .Case("small", llvm::CodeModel::Small)
 353                            .Case("kernel", llvm::CodeModel::Kernel)
 354                            .Case("medium", llvm::CodeModel::Medium)
 355                            .Case("large", llvm::CodeModel::Large)
 356                            .Case("default", ~1u)
 357                            .Default(~0u);
 358   assert(CodeModel != ~0u && "invalid code model!");
 359   if (CodeModel == ~1u)
 360     return None;
 361   return static_cast<llvm::CodeModel::Model>(CodeModel);
 362 }
 363
 364 static llvm::Reloc::Model getRelocModel(const CodeGenOptions &CodeGenOpts) {
 365   // Keep this synced with the equivalent code in
 366   // lib/Frontend/CompilerInvocation.cpp
 367   llvm::Optional<llvm::Reloc::Model> RM;
 368   RM = llvm::StringSwitch<llvm::Reloc::Model>(CodeGenOpts.RelocationModel)
 369       .Case("static", llvm::Reloc::Static)
 370       .Case("pic", llvm::Reloc::PIC_)
 371       .Case("ropi", llvm::Reloc::ROPI)
 372       .Case("rwpi", llvm::Reloc::RWPI)
 373       .Case("ropi-rwpi", llvm::Reloc::ROPI_RWPI)
 374       .Case("dynamic-no-pic", llvm::Reloc::DynamicNoPIC);
 375   assert(RM.hasValue() && "invalid PIC model!");
 376   return *RM;
 377 }
 378
 379 static TargetMachine::CodeGenFileType getCodeGenFileType(BackendAction Action) {
 380   if (Action == Backend_EmitObj)
 381     return TargetMachine::CGFT_ObjectFile;
 382   else if (Action == Backend_EmitMCNull)
 383     return TargetMachine::CGFT_Null;
 384   else {
 385     assert(Action == Backend_EmitAssembly && "Invalid action!");
 386     return TargetMachine::CGFT_AssemblyFile;
 387   }
 388 }
 389
 390 static void initTargetOptions(llvm::TargetOptions &Options,
 391                               const CodeGenOptions &CodeGenOpts,
 392                               const clang::TargetOptions &TargetOpts,
 393                               const LangOptions &LangOpts,
 394                               const HeaderSearchOptions &HSOpts) {
 395   Options.ThreadModel =
 396       llvm::StringSwitch<llvm::ThreadModel::Model>(CodeGenOpts.ThreadModel)
 397           .Case("posix", llvm::ThreadModel::POSIX)
 398           .Case("single", llvm::ThreadModel::Single);
 399
 400   // Set float ABI type.
 401   assert((CodeGenOpts.FloatABI == "soft" || CodeGenOpts.FloatABI == "softfp" ||
 402           CodeGenOpts.FloatABI == "hard" || CodeGenOpts.FloatABI.empty()) &&
 403          "Invalid Floating Point ABI!");
 404   Options.FloatABIType =
 405       llvm::StringSwitch<llvm::FloatABI::ABIType>(CodeGenOpts.FloatABI)
 406           .Case("soft", llvm::FloatABI::Soft)
 407           .Case("softfp", llvm::FloatABI::Soft)
 408           .Case("hard", llvm::FloatABI::Hard)
 409           .Default(llvm::FloatABI::Default);
 410
 411   // Set FP fusion mode.
 412   switch (LangOpts.getDefaultFPContractMode()) {
 413   case LangOptions::FPC_Off:
 414     // Preserve any contraction performed by the front-end.  (Strict performs
 415     // splitting of the muladd instrinsic in the backend.)
 416     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
 417     break;
 418   case LangOptions::FPC_On:
 419     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
 420     break;
 421   case LangOptions::FPC_Fast:
 422     Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
 423     break;
 424   }
 425
 426   Options.UseInitArray = CodeGenOpts.UseInitArray;
 427   Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
 428   Options.CompressDebugSections = CodeGenOpts.getCompressDebugSections();
 429   Options.RelaxELFRelocations = CodeGenOpts.RelaxELFRelocations;
 430
 431   // Set EABI version.
 432   Options.EABIVersion = TargetOpts.EABIVersion;
 433
 434   if (LangOpts.SjLjExceptions)
 435     Options.ExceptionModel = llvm::ExceptionHandling::SjLj;
 436   if (LangOpts.SEHExceptions)
 437     Options.ExceptionModel = llvm::ExceptionHandling::WinEH;
 438   if (LangOpts.DWARFExceptions)
 439     Options.ExceptionModel = llvm::ExceptionHandling::DwarfCFI;
 440
 441   Options.NoInfsFPMath = CodeGenOpts.NoInfsFPMath;
 442   Options.NoNaNsFPMath = CodeGenOpts.NoNaNsFPMath;
 443   Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
 444   Options.UnsafeFPMath = CodeGenOpts.UnsafeFPMath;
 445   Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
 446   Options.FunctionSections = CodeGenOpts.FunctionSections;
 447   Options.DataSections = CodeGenOpts.DataSections;
 448   Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
 449   Options.EmulatedTLS = CodeGenOpts.EmulatedTLS;
 450   Options.DebuggerTuning = CodeGenOpts.getDebuggerTuning();
 451
 452   if (CodeGenOpts.EnableSplitDwarf)
 453     Options.MCOptions.SplitDwarfFile = CodeGenOpts.SplitDwarfFile;
 454   Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
 455   Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
 456   Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
 457   Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
 458   Options.MCOptions.MCIncrementalLinkerCompatible =
 459       CodeGenOpts.IncrementalLinkerCompatible;
 460   Options.MCOptions.MCPIECopyRelocations = CodeGenOpts.PIECopyRelocations;
 461   Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
 462   Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
 463   Options.MCOptions.PreserveAsmComments = CodeGenOpts.PreserveAsmComments;
 464   Options.MCOptions.ABIName = TargetOpts.ABI;
 465   for (const auto &Entry : HSOpts.UserEntries)
 466     if (!Entry.IsFramework &&
 467         (Entry.Group == frontend::IncludeDirGroup::Quoted ||
 468          Entry.Group == frontend::IncludeDirGroup::Angled ||
 469          Entry.Group == frontend::IncludeDirGroup::System))
 470       Options.MCOptions.IASSearchPaths.push_back(
 471           Entry.IgnoreSysRoot ? Entry.Path : HSOpts.Sysroot + Entry.Path);
 472 }
 473
 474 void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
 475                                       legacy::FunctionPassManager &FPM) {
 476   // Handle disabling of all LLVM passes, where we want to preserve the
 477   // internal module before any optimization.
 478   if (CodeGenOpts.DisableLLVMPasses)
 479     return;
 480
 481   // Figure out TargetLibraryInfo.  This needs to be added to MPM and FPM
 482   // manually (and not via PMBuilder), since some passes (eg. InstrProfiling)
 483   // are inserted before PMBuilder ones - they'd get the default-constructed
 484   // TLI with an unknown target otherwise.
 485   Triple TargetTriple(TheModule->getTargetTriple());
 486   std::unique_ptr<TargetLibraryInfoImpl> TLII(
 487       createTLII(TargetTriple, CodeGenOpts));
 488
 489   PassManagerBuilderWrapper PMBuilder(TargetTriple, CodeGenOpts, LangOpts);
 490
 491   // At O0 and O1 we only run the always inliner which is more efficient. At
 492   // higher optimization levels we run the normal inliner.
 493   if (CodeGenOpts.OptimizationLevel <= 1) {
 494     bool InsertLifetimeIntrinsics = (CodeGenOpts.OptimizationLevel != 0 &&
 495                                      !CodeGenOpts.DisableLifetimeMarkers);
 496     PMBuilder.Inliner = createAlwaysInlinerLegacyPass(InsertLifetimeIntrinsics);
 497   } else {
 498     // We do not want to inline hot callsites for SamplePGO module-summary build
 499     // because profile annotation will happen again in ThinLTO backend, and we
 500     // want the IR of the hot path to match the profile.
 501     PMBuilder.Inliner = createFunctionInliningPass(
 502         CodeGenOpts.OptimizationLevel, CodeGenOpts.OptimizeSize,
 503         (!CodeGenOpts.SampleProfileFile.empty() &&
 504          CodeGenOpts.EmitSummaryIndex));
 505   }
 506
 507   PMBuilder.OptLevel = CodeGenOpts.OptimizationLevel;
 508   PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
 509   PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
 510   PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
 511
 512   PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
 513   PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
 514   PMBuilder.PrepareForThinLTO = CodeGenOpts.EmitSummaryIndex;
 515   PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
 516   PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
 517
 518   MPM.add(new TargetLibraryInfoWrapperPass(*TLII));
 519
 520   if (TM)
 521     TM->adjustPassManager(PMBuilder);
 522
 523   if (CodeGenOpts.DebugInfoForProfiling ||
 524       !CodeGenOpts.SampleProfileFile.empty())
 525     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
 526                            addAddDiscriminatorsPass);
 527
 528   // In ObjC ARC mode, add the main ARC optimization passes.
 529   if (LangOpts.ObjCAutoRefCount) {
 530     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
 531                            addObjCARCExpandPass);
 532     PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
 533                            addObjCARCAPElimPass);
 534     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
 535                            addObjCARCOptPass);
 536   }
 537
 538   if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds)) {
 539     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
 540                            addBoundsCheckingPass);
 541     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 542                            addBoundsCheckingPass);
 543   }
 544
 545   if (CodeGenOpts.SanitizeCoverageType ||
 546       CodeGenOpts.SanitizeCoverageIndirectCalls ||
 547       CodeGenOpts.SanitizeCoverageTraceCmp) {
 548     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 549                            addSanitizerCoveragePass);
 550     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 551                            addSanitizerCoveragePass);
 552   }
 553
 554   if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
 555     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 556                            addAddressSanitizerPasses);
 557     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 558                            addAddressSanitizerPasses);
 559   }
 560
 561   if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
 562     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 563                            addKernelAddressSanitizerPasses);
 564     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 565                            addKernelAddressSanitizerPasses);
 566   }
 567
 568   if (LangOpts.Sanitize.has(SanitizerKind::HWAddress)) {
 569     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 570                            addHWAddressSanitizerPasses);
 571     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 572                            addHWAddressSanitizerPasses);
 573   }
 574
 575   if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
 576     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 577                            addMemorySanitizerPass);
 578     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 579                            addMemorySanitizerPass);
 580   }
 581
 582   if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
 583     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 584                            addThreadSanitizerPass);
 585     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 586                            addThreadSanitizerPass);
 587   }
 588
 589   if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
 590     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 591                            addDataFlowSanitizerPass);
 592     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 593                            addDataFlowSanitizerPass);
 594   }
 595
 596   if (LangOpts.CoroutinesTS)
 597     addCoroutinePassesToExtensionPoints(PMBuilder);
 598
 599   if (LangOpts.Sanitize.hasOneOf(SanitizerKind::Efficiency)) {
 600     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 601                            addEfficiencySanitizerPass);
 602     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 603                            addEfficiencySanitizerPass);
 604   }
 605
 606   // Set up the per-function pass manager.
 607   FPM.add(new TargetLibraryInfoWrapperPass(*TLII));
 608   if (CodeGenOpts.VerifyModule)
 609     FPM.add(createVerifierPass());
 610
 611   // Set up the per-module pass manager.
 612   if (!CodeGenOpts.RewriteMapFiles.empty())
 613     addSymbolRewriterPass(CodeGenOpts, &MPM);
 614
 615   if (!CodeGenOpts.DisableGCov &&
 616       (CodeGenOpts.EmitGcovArcs || CodeGenOpts.EmitGcovNotes)) {
 617     // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
 618     // LLVM's -default-gcov-version flag is set to something invalid.
 619     GCOVOptions Options;
 620     Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
 621     Options.EmitData = CodeGenOpts.EmitGcovArcs;
 622     memcpy(Options.Version, CodeGenOpts.CoverageVersion, 4);
 623     Options.UseCfgChecksum = CodeGenOpts.CoverageExtraChecksum;
 624     Options.NoRedZone = CodeGenOpts.DisableRedZone;
 625     Options.FunctionNamesInData =
 626         !CodeGenOpts.CoverageNoFunctionNamesInData;
 627     Options.ExitBlockBeforeBody = CodeGenOpts.CoverageExitBlockBeforeBody;
 628     MPM.add(createGCOVProfilerPass(Options));
 629     if (CodeGenOpts.getDebugInfo() == codegenoptions::NoDebugInfo)
 630       MPM.add(createStripSymbolsPass(true));
 631   }
 632
 633   if (CodeGenOpts.hasProfileClangInstr()) {
 634     InstrProfOptions Options;
 635     Options.NoRedZone = CodeGenOpts.DisableRedZone;
 636     Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
 637     MPM.add(createInstrProfilingLegacyPass(Options));
 638   }
 639   if (CodeGenOpts.hasProfileIRInstr()) {
 640     PMBuilder.EnablePGOInstrGen = true;
 641     if (!CodeGenOpts.InstrProfileOutput.empty())
 642       PMBuilder.PGOInstrGen = CodeGenOpts.InstrProfileOutput;
 643     else
 644       PMBuilder.PGOInstrGen = DefaultProfileGenName;
 645   }
 646   if (CodeGenOpts.hasProfileIRUse())
 647     PMBuilder.PGOInstrUse = CodeGenOpts.ProfileInstrumentUsePath;
 648
 649   if (!CodeGenOpts.SampleProfileFile.empty())
 650     PMBuilder.PGOSampleUse = CodeGenOpts.SampleProfileFile;
 651
 652   PMBuilder.populateFunctionPassManager(FPM);
 653   PMBuilder.populateModulePassManager(MPM);
 654 }
 655
 656 static void setCommandLineOpts(const CodeGenOptions &CodeGenOpts) {
 657   SmallVector<const char *, 16> BackendArgs;
 658   BackendArgs.push_back("clang"); // Fake program name.
 659   if (!CodeGenOpts.DebugPass.empty()) {
 660     BackendArgs.push_back("-debug-pass");
 661     BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
 662   }
 663   if (!CodeGenOpts.LimitFloatPrecision.empty()) {
 664     BackendArgs.push_back("-limit-float-precision");
 665     BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
 666   }
 667   for (const std::string &BackendOption : CodeGenOpts.BackendOptions)
 668     BackendArgs.push_back(BackendOption.c_str());
 669   BackendArgs.push_back(nullptr);
 670   llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
 671                                     BackendArgs.data());
 672 }
 673
 674 void EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
 675   // Create the TargetMachine for generating code.
 676   std::string Error;
 677   std::string Triple = TheModule->getTargetTriple();
 678   const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
 679   if (!TheTarget) {
 680     if (MustCreateTM)
 681       Diags.Report(diag::err_fe_unable_to_create_target) << Error;
 682     return;
 683   }
 684
 685   Optional<llvm::CodeModel::Model> CM = getCodeModel(CodeGenOpts);
 686   std::string FeaturesStr =
 687       llvm::join(TargetOpts.Features.begin(), TargetOpts.Features.end(), ",");
 688   llvm::Reloc::Model RM = getRelocModel(CodeGenOpts);
 689   CodeGenOpt::Level OptLevel = getCGOptLevel(CodeGenOpts);
 690
 691   llvm::TargetOptions Options;
 692   initTargetOptions(Options, CodeGenOpts, TargetOpts, LangOpts, HSOpts);
 693   TM.reset(TheTarget->createTargetMachine(Triple, TargetOpts.CPU, FeaturesStr,
 694                                           Options, RM, CM, OptLevel));
 695 }
 696
 697 bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
 698                                        BackendAction Action,
 699                                        raw_pwrite_stream &OS) {
 700   // Add LibraryInfo.
 701   llvm::Triple TargetTriple(TheModule->getTargetTriple());
 702   std::unique_ptr<TargetLibraryInfoImpl> TLII(
 703       createTLII(TargetTriple, CodeGenOpts));
 704   CodeGenPasses.add(new TargetLibraryInfoWrapperPass(*TLII));
 705
 706   // Normal mode, emit a .s or .o file by running the code generator. Note,
 707   // this also adds codegenerator level optimization passes.
 708   TargetMachine::CodeGenFileType CGFT = getCodeGenFileType(Action);
 709
 710   // Add ObjC ARC final-cleanup optimizations. This is done as part of the
 711   // "codegen" passes so that it isn't run multiple times when there is
 712   // inlining happening.
 713   if (CodeGenOpts.OptimizationLevel > 0)
 714     CodeGenPasses.add(createObjCARCContractPass());
 715
 716   if (TM->addPassesToEmitFile(CodeGenPasses, OS, CGFT,
 717                               /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
 718     Diags.Report(diag::err_fe_unable_to_interface_with_target);
 719     return false;
 720   }
 721
 722   return true;
 723 }
 724
 725 void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
 726                                       std::unique_ptr<raw_pwrite_stream> OS) {
 727   TimeRegion Region(llvm::TimePassesIsEnabled ? &CodeGenerationTime : nullptr);
 728
 729   setCommandLineOpts(CodeGenOpts);
 730
 731   bool UsesCodeGen = (Action != Backend_EmitNothing &&
 732                       Action != Backend_EmitBC &&
 733                       Action != Backend_EmitLL);
 734   CreateTargetMachine(UsesCodeGen);
 735
 736   if (UsesCodeGen && !TM)
 737     return;
 738   if (TM)
 739     TheModule->setDataLayout(TM->createDataLayout());
 740
 741   legacy::PassManager PerModulePasses;
 742   PerModulePasses.add(
 743       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
 744
 745   legacy::FunctionPassManager PerFunctionPasses(TheModule);
 746   PerFunctionPasses.add(
 747       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
 748
 749   CreatePasses(PerModulePasses, PerFunctionPasses);
 750
 751   legacy::PassManager CodeGenPasses;
 752   CodeGenPasses.add(
 753       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
 754
 755   std::unique_ptr<raw_fd_ostream> ThinLinkOS;
 756
 757   switch (Action) {
 758   case Backend_EmitNothing:
 759     break;
 760
 761   case Backend_EmitBC:
 762     if (CodeGenOpts.EmitSummaryIndex) {
 763       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
 764         std::error_code EC;
 765         ThinLinkOS.reset(new llvm::raw_fd_ostream(
 766             CodeGenOpts.ThinLinkBitcodeFile, EC,
 767             llvm::sys::fs::F_None));
 768         if (EC) {
 769           Diags.Report(diag::err_fe_unable_to_open_output) << CodeGenOpts.ThinLinkBitcodeFile
 770                                                            << EC.message();
 771           return;
 772         }
 773       }
 774       PerModulePasses.add(
 775           createWriteThinLTOBitcodePass(*OS, ThinLinkOS.get()));
 776     }
 777     else
 778       PerModulePasses.add(
 779           createBitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists));
 780     break;
 781
 782   case Backend_EmitLL:
 783     PerModulePasses.add(
 784         createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
 785     break;
 786
 787   default:
 788     if (!AddEmitPasses(CodeGenPasses, Action, *OS))
 789       return;
 790   }
 791
 792   // Before executing passes, print the final values of the LLVM options.
 793   cl::PrintOptionValues();
 794
 795   // Run passes. For now we do all passes at once, but eventually we
 796   // would like to have the option of streaming code generation.
 797
 798   {
 799     PrettyStackTraceString CrashInfo("Per-function optimization");
 800
 801     PerFunctionPasses.doInitialization();
 802     for (Function &F : *TheModule)
 803       if (!F.isDeclaration())
 804         PerFunctionPasses.run(F);
 805     PerFunctionPasses.doFinalization();
 806   }
 807
 808   {
 809     PrettyStackTraceString CrashInfo("Per-module optimization passes");
 810     PerModulePasses.run(*TheModule);
 811   }
 812
 813   {
 814     PrettyStackTraceString CrashInfo("Code generation");
 815     CodeGenPasses.run(*TheModule);
 816   }
 817 }
 818
 819 static PassBuilder::OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
 820   switch (Opts.OptimizationLevel) {
 821   default:
 822     llvm_unreachable("Invalid optimization level!");
 823
 824   case 1:
 825     return PassBuilder::O1;
 826
 827   case 2:
 828     switch (Opts.OptimizeSize) {
 829     default:
 830       llvm_unreachable("Invalide optimization level for size!");
 831
 832     case 0:
 833       return PassBuilder::O2;
 834
 835     case 1:
 836       return PassBuilder::Os;
 837
 838     case 2:
 839       return PassBuilder::Oz;
 840     }
 841
 842   case 3:
 843     return PassBuilder::O3;
 844   }
 845 }
 846
 847 /// A clean version of `EmitAssembly` that uses the new pass manager.
 848 ///
 849 /// Not all features are currently supported in this system, but where
 850 /// necessary it falls back to the legacy pass manager to at least provide
 851 /// basic functionality.
 852 ///
 853 /// This API is planned to have its functionality finished and then to replace
 854 /// `EmitAssembly` at some point in the future when the default switches.
 855 void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
 856     BackendAction Action, std::unique_ptr<raw_pwrite_stream> OS) {
 857   TimeRegion Region(llvm::TimePassesIsEnabled ? &CodeGenerationTime : nullptr);
 858   setCommandLineOpts(CodeGenOpts);
 859
 860   // The new pass manager always makes a target machine available to passes
 861   // during construction.
 862   CreateTargetMachine(/*MustCreateTM*/ true);
 863   if (!TM)
 864     // This will already be diagnosed, just bail.
 865     return;
 866   TheModule->setDataLayout(TM->createDataLayout());
 867
 868   Optional<PGOOptions> PGOOpt;
 869
 870   if (CodeGenOpts.hasProfileIRInstr())
 871     // -fprofile-generate.
 872     PGOOpt = PGOOptions(CodeGenOpts.InstrProfileOutput.empty()
 873                             ? DefaultProfileGenName
 874                             : CodeGenOpts.InstrProfileOutput,
 875                         "", "", true, CodeGenOpts.DebugInfoForProfiling);
 876   else if (CodeGenOpts.hasProfileIRUse())
 877     // -fprofile-use.
 878     PGOOpt = PGOOptions("", CodeGenOpts.ProfileInstrumentUsePath, "", false,
 879                         CodeGenOpts.DebugInfoForProfiling);
 880   else if (!CodeGenOpts.SampleProfileFile.empty())
 881     // -fprofile-sample-use
 882     PGOOpt = PGOOptions("", "", CodeGenOpts.SampleProfileFile, false,
 883                         CodeGenOpts.DebugInfoForProfiling);
 884   else if (CodeGenOpts.DebugInfoForProfiling)
 885     // -fdebug-info-for-profiling
 886     PGOOpt = PGOOptions("", "", "", false, true);
 887
 888   PassBuilder PB(TM.get(), PGOOpt);
 889
 890   LoopAnalysisManager LAM(CodeGenOpts.DebugPassManager);
 891   FunctionAnalysisManager FAM(CodeGenOpts.DebugPassManager);
 892   CGSCCAnalysisManager CGAM(CodeGenOpts.DebugPassManager);
 893   ModuleAnalysisManager MAM(CodeGenOpts.DebugPassManager);
 894
 895   // Register the AA manager first so that our version is the one used.
 896   FAM.registerPass([&] { return PB.buildDefaultAAPipeline(); });
 897
 898   // Register the target library analysis directly and give it a customized
 899   // preset TLI.
 900   Triple TargetTriple(TheModule->getTargetTriple());
 901   std::unique_ptr<TargetLibraryInfoImpl> TLII(
 902       createTLII(TargetTriple, CodeGenOpts));
 903   FAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); });
 904   MAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); });
 905
 906   // Register all the basic analyses with the managers.
 907   PB.registerModuleAnalyses(MAM);
 908   PB.registerCGSCCAnalyses(CGAM);
 909   PB.registerFunctionAnalyses(FAM);
 910   PB.registerLoopAnalyses(LAM);
 911   PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
 912
 913   ModulePassManager MPM(CodeGenOpts.DebugPassManager);
 914
 915   if (!CodeGenOpts.DisableLLVMPasses) {
 916     bool IsThinLTO = CodeGenOpts.EmitSummaryIndex;
 917     bool IsLTO = CodeGenOpts.PrepareForLTO;
 918
 919     if (CodeGenOpts.OptimizationLevel == 0) {
 920       // Build a minimal pipeline based on the semantics required by Clang,
 921       // which is just that always inlining occurs.
 922       MPM.addPass(AlwaysInlinerPass());
 923
 924       // At -O0 we directly run necessary sanitizer passes.
 925       if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
 926         MPM.addPass(createModuleToFunctionPassAdaptor(BoundsCheckingPass()));
 927
 928       // Lastly, add a semantically necessary pass for ThinLTO.
 929       if (IsThinLTO)
 930         MPM.addPass(NameAnonGlobalPass());
 931     } else {
 932       // Map our optimization levels into one of the distinct levels used to
 933       // configure the pipeline.
 934       PassBuilder::OptimizationLevel Level = mapToLevel(CodeGenOpts);
 935
 936       // Register callbacks to schedule sanitizer passes at the appropriate part of
 937       // the pipeline.
 938       if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
 939         PB.registerScalarOptimizerLateEPCallback(
 940             [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
 941               FPM.addPass(BoundsCheckingPass());
 942             });
 943
 944       if (IsThinLTO) {
 945         MPM = PB.buildThinLTOPreLinkDefaultPipeline(
 946             Level, CodeGenOpts.DebugPassManager);
 947         MPM.addPass(NameAnonGlobalPass());
 948       } else if (IsLTO) {
 949         MPM = PB.buildLTOPreLinkDefaultPipeline(Level,
 950                                                 CodeGenOpts.DebugPassManager);
 951       } else {
 952         MPM = PB.buildPerModuleDefaultPipeline(Level,
 953                                                CodeGenOpts.DebugPassManager);
 954       }
 955     }
 956   }
 957
 958   // FIXME: We still use the legacy pass manager to do code generation. We
 959   // create that pass manager here and use it as needed below.
 960   legacy::PassManager CodeGenPasses;
 961   bool NeedCodeGen = false;
 962   Optional<raw_fd_ostream> ThinLinkOS;
 963
 964   // Append any output we need to the pass manager.
 965   switch (Action) {
 966   case Backend_EmitNothing:
 967     break;
 968
 969   case Backend_EmitBC:
 970     if (CodeGenOpts.EmitSummaryIndex) {
 971       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
 972         std::error_code EC;
 973         ThinLinkOS.emplace(CodeGenOpts.ThinLinkBitcodeFile, EC,
 974                            llvm::sys::fs::F_None);
 975         if (EC) {
 976           Diags.Report(diag::err_fe_unable_to_open_output)
 977               << CodeGenOpts.ThinLinkBitcodeFile << EC.message();
 978           return;
 979         }
 980       }
 981       MPM.addPass(
 982           ThinLTOBitcodeWriterPass(*OS, ThinLinkOS ? &*ThinLinkOS : nullptr));
 983     } else {
 984       MPM.addPass(BitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists,
 985                                     CodeGenOpts.EmitSummaryIndex,
 986                                     CodeGenOpts.EmitSummaryIndex));
 987     }
 988     break;
 989
 990   case Backend_EmitLL:
 991     MPM.addPass(PrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
 992     break;
 993
 994   case Backend_EmitAssembly:
 995   case Backend_EmitMCNull:
 996   case Backend_EmitObj:
 997     NeedCodeGen = true;
 998     CodeGenPasses.add(
 999         createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
1000     if (!AddEmitPasses(CodeGenPasses, Action, *OS))
1001       // FIXME: Should we handle this error differently?
1002       return;
1003     break;
1004   }
1005
1006   // Before executing passes, print the final values of the LLVM options.
1007   cl::PrintOptionValues();
1008
1009   // Now that we have all of the passes ready, run them.
1010   {
1011     PrettyStackTraceString CrashInfo("Optimizer");
1012     MPM.run(*TheModule, MAM);
1013   }
1014
1015   // Now if needed, run the legacy PM for codegen.
1016   if (NeedCodeGen) {
1017     PrettyStackTraceString CrashInfo("Code generation");
1018     CodeGenPasses.run(*TheModule);
1019   }
1020 }
1021
1022 Expected<BitcodeModule> clang::FindThinLTOModule(MemoryBufferRef MBRef) {
1023   Expected<std::vector<BitcodeModule>> BMsOrErr = getBitcodeModuleList(MBRef);
1024   if (!BMsOrErr)
1025     return BMsOrErr.takeError();
1026
1027   // The bitcode file may contain multiple modules, we want the one that is
1028   // marked as being the ThinLTO module.
1029   for (BitcodeModule &BM : *BMsOrErr) {
1030     Expected<BitcodeLTOInfo> LTOInfo = BM.getLTOInfo();
1031     if (LTOInfo && LTOInfo->IsThinLTO)
1032       return BM;
1033   }
1034
1035   return make_error<StringError>("Could not find module summary",
1036                                  inconvertibleErrorCode());
1037 }
1038
1039 static void runThinLTOBackend(ModuleSummaryIndex *CombinedIndex, Module *M,
1040                               const HeaderSearchOptions &HeaderOpts,
1041                               const CodeGenOptions &CGOpts,
1042                               const clang::TargetOptions &TOpts,
1043                               const LangOptions &LOpts,
1044                               std::unique_ptr<raw_pwrite_stream> OS,
1045                               std::string SampleProfile,
1046                               BackendAction Action) {
1047   StringMap<DenseMap<GlobalValue::GUID, GlobalValueSummary *>>
1048       ModuleToDefinedGVSummaries;
1049   CombinedIndex->collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries);
1050
1051   setCommandLineOpts(CGOpts);
1052
1053   // We can simply import the values mentioned in the combined index, since
1054   // we should only invoke this using the individual indexes written out
1055   // via a WriteIndexesThinBackend.
1056   FunctionImporter::ImportMapTy ImportList;
1057   for (auto &GlobalList : *CombinedIndex) {
1058     // Ignore entries for undefined references.
1059     if (GlobalList.second.SummaryList.empty())
1060       continue;
1061
1062     auto GUID = GlobalList.first;
1063     assert(GlobalList.second.SummaryList.size() == 1 &&
1064            "Expected individual combined index to have one summary per GUID");
1065     auto &Summary = GlobalList.second.SummaryList[0];
1066     // Skip the summaries for the importing module. These are included to
1067     // e.g. record required linkage changes.
1068     if (Summary->modulePath() == M->getModuleIdentifier())
1069       continue;
1070     // Doesn't matter what value we plug in to the map, just needs an entry
1071     // to provoke importing by thinBackend.
1072     ImportList[Summary->modulePath()][GUID] = 1;
1073   }
1074
1075   std::vector<std::unique_ptr<llvm::MemoryBuffer>> OwnedImports;
1076   MapVector<llvm::StringRef, llvm::BitcodeModule> ModuleMap;
1077
1078   for (auto &I : ImportList) {
1079     ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> MBOrErr =
1080         llvm::MemoryBuffer::getFile(I.first());
1081     if (!MBOrErr) {
1082       errs() << "Error loading imported file '" << I.first()
1083              << "': " << MBOrErr.getError().message() << "\n";
1084       return;
1085     }
1086
1087     Expected<BitcodeModule> BMOrErr = FindThinLTOModule(**MBOrErr);
1088     if (!BMOrErr) {
1089       handleAllErrors(BMOrErr.takeError(), [&](ErrorInfoBase &EIB) {
1090         errs() << "Error loading imported file '" << I.first()
1091                << "': " << EIB.message() << '\n';
1092       });
1093       return;
1094     }
1095     ModuleMap.insert({I.first(), *BMOrErr});
1096
1097     OwnedImports.push_back(std::move(*MBOrErr));
1098   }
1099   auto AddStream = [&](size_t Task) {
1100     return llvm::make_unique<lto::NativeObjectStream>(std::move(OS));
1101   };
1102   lto::Config Conf;
1103   Conf.CPU = TOpts.CPU;
1104   Conf.CodeModel = getCodeModel(CGOpts);
1105   Conf.MAttrs = TOpts.Features;
1106   Conf.RelocModel = getRelocModel(CGOpts);
1107   Conf.CGOptLevel = getCGOptLevel(CGOpts);
1108   initTargetOptions(Conf.Options, CGOpts, TOpts, LOpts, HeaderOpts);
1109   Conf.SampleProfile = std::move(SampleProfile);
1110   Conf.UseNewPM = CGOpts.ExperimentalNewPassManager;
1111   Conf.DebugPassManager = CGOpts.DebugPassManager;
1112   switch (Action) {
1113   case Backend_EmitNothing:
1114     Conf.PreCodeGenModuleHook = [](size_t Task, const Module &Mod) {
1115       return false;
1116     };
1117     break;
1118   case Backend_EmitLL:
1119     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1120       M->print(*OS, nullptr, CGOpts.EmitLLVMUseLists);
1121       return false;
1122     };
1123     break;
1124   case Backend_EmitBC:
1125     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1126       WriteBitcodeToFile(M, *OS, CGOpts.EmitLLVMUseLists);
1127       return false;
1128     };
1129     break;
1130   default:
1131     Conf.CGFileType = getCodeGenFileType(Action);
1132     break;
1133   }
1134   if (Error E = thinBackend(
1135           Conf, 0, AddStream, *M, *CombinedIndex, ImportList,
1136           ModuleToDefinedGVSummaries[M->getModuleIdentifier()], ModuleMap)) {
1137     handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1138       errs() << "Error running ThinLTO backend: " << EIB.message() << '\n';
1139     });
1140   }
1141 }
1142
1143 void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
1144                               const HeaderSearchOptions &HeaderOpts,
1145                               const CodeGenOptions &CGOpts,
1146                               const clang::TargetOptions &TOpts,
1147                               const LangOptions &LOpts,
1148                               const llvm::DataLayout &TDesc, Module *M,
1149                               BackendAction Action,
1150                               std::unique_ptr<raw_pwrite_stream> OS) {
1151   if (!CGOpts.ThinLTOIndexFile.empty()) {
1152     // If we are performing a ThinLTO importing compile, load the function index
1153     // into memory and pass it into runThinLTOBackend, which will run the
1154     // function importer and invoke LTO passes.
1155     Expected<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
1156         llvm::getModuleSummaryIndexForFile(CGOpts.ThinLTOIndexFile,
1157                                            /*IgnoreEmptyThinLTOIndexFile*/true);
1158     if (!IndexOrErr) {
1159       logAllUnhandledErrors(IndexOrErr.takeError(), errs(),
1160                             "Error loading index file '" +
1161                             CGOpts.ThinLTOIndexFile + "': ");
1162       return;
1163     }
1164     std::unique_ptr<ModuleSummaryIndex> CombinedIndex = std::move(*IndexOrErr);
1165     // A null CombinedIndex means we should skip ThinLTO compilation
1166     // (LLVM will optionally ignore empty index files, returning null instead
1167     // of an error).
1168     bool DoThinLTOBackend = CombinedIndex != nullptr;
1169     if (DoThinLTOBackend) {
1170       runThinLTOBackend(CombinedIndex.get(), M, HeaderOpts, CGOpts, TOpts,
1171                         LOpts, std::move(OS), CGOpts.SampleProfileFile, Action);
1172       return;
1173     }
1174   }
1175
1176   EmitAssemblyHelper AsmHelper(Diags, HeaderOpts, CGOpts, TOpts, LOpts, M);
1177
1178   if (CGOpts.ExperimentalNewPassManager)
1179     AsmHelper.EmitAssemblyWithNewPassManager(Action, std::move(OS));
1180   else
1181     AsmHelper.EmitAssembly(Action, std::move(OS));
1182
1183   // Verify clang's TargetInfo DataLayout against the LLVM TargetMachine's
1184   // DataLayout.
1185   if (AsmHelper.TM) {
1186     std::string DLDesc = M->getDataLayout().getStringRepresentation();
1187     if (DLDesc != TDesc.getStringRepresentation()) {
1188       unsigned DiagID = Diags.getCustomDiagID(
1189           DiagnosticsEngine::Error, "backend data layout '%0' does not match "
1190                                     "expected target description '%1'");
1191       Diags.Report(DiagID) << DLDesc << TDesc.getStringRepresentation();
1192     }
1193   }
1194 }
1195
1196 static const char* getSectionNameForBitcode(const Triple &T) {
1197   switch (T.getObjectFormat()) {
1198   case Triple::MachO:
1199     return "__LLVM,__bitcode";
1200   case Triple::COFF:
1201   case Triple::ELF:
1202   case Triple::Wasm:
1203   case Triple::UnknownObjectFormat:
1204     return ".llvmbc";
1205   }
1206   llvm_unreachable("Unimplemented ObjectFormatType");
1207 }
1208
1209 static const char* getSectionNameForCommandline(const Triple &T) {
1210   switch (T.getObjectFormat()) {
1211   case Triple::MachO:
1212     return "__LLVM,__cmdline";
1213   case Triple::COFF:
1214   case Triple::ELF:
1215   case Triple::Wasm:
1216   case Triple::UnknownObjectFormat:
1217     return ".llvmcmd";
1218   }
1219   llvm_unreachable("Unimplemented ObjectFormatType");
1220 }
1221
1222 // With -fembed-bitcode, save a copy of the llvm IR as data in the
1223 // __LLVM,__bitcode section.
1224 void clang::EmbedBitcode(llvm::Module *M, const CodeGenOptions &CGOpts,
1225                          llvm::MemoryBufferRef Buf) {
1226   if (CGOpts.getEmbedBitcode() == CodeGenOptions::Embed_Off)
1227     return;
1228
1229   // Save llvm.compiler.used and remote it.
1230   SmallVector<Constant*, 2> UsedArray;
1231   SmallSet<GlobalValue*, 4> UsedGlobals;
1232   Type *UsedElementType = Type::getInt8Ty(M->getContext())->getPointerTo(0);
1233   GlobalVariable *Used = collectUsedGlobalVariables(*M, UsedGlobals, true);
1234   for (auto *GV : UsedGlobals) {
1235     if (GV->getName() != "llvm.embedded.module" &&
1236         GV->getName() != "llvm.cmdline")
1237       UsedArray.push_back(
1238           ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
1239   }
1240   if (Used)
1241     Used->eraseFromParent();
1242
1243   // Embed the bitcode for the llvm module.
1244   std::string Data;
1245   ArrayRef<uint8_t> ModuleData;
1246   Triple T(M->getTargetTriple());
1247   // Create a constant that contains the bitcode.
1248   // In case of embedding a marker, ignore the input Buf and use the empty
1249   // ArrayRef. It is also legal to create a bitcode marker even Buf is empty.
1250   if (CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Marker) {
1251     if (!isBitcode((const unsigned char *)Buf.getBufferStart(),
1252                    (const unsigned char *)Buf.getBufferEnd())) {
1253       // If the input is LLVM Assembly, bitcode is produced by serializing
1254       // the module. Use-lists order need to be perserved in this case.
1255       llvm::raw_string_ostream OS(Data);
1256       llvm::WriteBitcodeToFile(M, OS, /* ShouldPreserveUseListOrder */ true);
1257       ModuleData =
1258           ArrayRef<uint8_t>((const uint8_t *)OS.str().data(), OS.str().size());
1259     } else
1260       // If the input is LLVM bitcode, write the input byte stream directly.
1261       ModuleData = ArrayRef<uint8_t>((const uint8_t *)Buf.getBufferStart(),
1262                                      Buf.getBufferSize());
1263   }
1264   llvm::Constant *ModuleConstant =
1265       llvm::ConstantDataArray::get(M->getContext(), ModuleData);
1266   llvm::GlobalVariable *GV = new llvm::GlobalVariable(
1267       *M, ModuleConstant->getType(), true, llvm::GlobalValue::PrivateLinkage,
1268       ModuleConstant);
1269   GV->setSection(getSectionNameForBitcode(T));
1270   UsedArray.push_back(
1271       ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
1272   if (llvm::GlobalVariable *Old =
1273           M->getGlobalVariable("llvm.embedded.module", true)) {
1274     assert(Old->hasOneUse() &&
1275            "llvm.embedded.module can only be used once in llvm.compiler.used");
1276     GV->takeName(Old);
1277     Old->eraseFromParent();
1278   } else {
1279     GV->setName("llvm.embedded.module");
1280   }
1281
1282   // Skip if only bitcode needs to be embedded.
1283   if (CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Bitcode) {
1284     // Embed command-line options.
1285     ArrayRef<uint8_t> CmdData(const_cast<uint8_t *>(CGOpts.CmdArgs.data()),
1286                               CGOpts.CmdArgs.size());
1287     llvm::Constant *CmdConstant =
1288       llvm::ConstantDataArray::get(M->getContext(), CmdData);
1289     GV = new llvm::GlobalVariable(*M, CmdConstant->getType(), true,
1290                                   llvm::GlobalValue::PrivateLinkage,
1291                                   CmdConstant);
1292     GV->setSection(getSectionNameForCommandline(T));
1293     UsedArray.push_back(
1294         ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
1295     if (llvm::GlobalVariable *Old =
1296             M->getGlobalVariable("llvm.cmdline", true)) {
1297       assert(Old->hasOneUse() &&
1298              "llvm.cmdline can only be used once in llvm.compiler.used");
1299       GV->takeName(Old);
1300       Old->eraseFromParent();
1301     } else {
1302       GV->setName("llvm.cmdline");
1303     }
1304   }
1305
1306   if (UsedArray.empty())
1307     return;
1308
1309   // Recreate llvm.compiler.used.
1310   ArrayType *ATy = ArrayType::get(UsedElementType, UsedArray.size());
1311   auto *NewUsed = new GlobalVariable(
1312       *M, ATy, false, llvm::GlobalValue::AppendingLinkage,
1313       llvm::ConstantArray::get(ATy, UsedArray), "llvm.compiler.used");
1314   NewUsed->setSection("llvm.metadata");
1315 }