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