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