contrib/llvm/tools/clang/lib/CodeGen/BackendUtil.cpp

   1 //===--- BackendUtil.cpp - LLVM Backend Utilities -------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "clang/CodeGen/BackendUtil.h"
  11 #include "clang/Basic/Diagnostic.h"
  12 #include "clang/Basic/LangOptions.h"
  13 #include "clang/Basic/TargetOptions.h"
  14 #include "clang/Frontend/CodeGenOptions.h"
  15 #include "clang/Frontend/FrontendDiagnostic.h"
  16 #include "clang/Frontend/Utils.h"
  17 #include "clang/Lex/HeaderSearchOptions.h"
  18 #include "llvm/ADT/SmallSet.h"
  19 #include "llvm/ADT/StringExtras.h"
  20 #include "llvm/ADT/StringSwitch.h"
  21 #include "llvm/ADT/Triple.h"
  22 #include "llvm/Analysis/TargetLibraryInfo.h"
  23 #include "llvm/Analysis/TargetTransformInfo.h"
  24 #include "llvm/Bitcode/BitcodeReader.h"
  25 #include "llvm/Bitcode/BitcodeWriter.h"
  26 #include "llvm/Bitcode/BitcodeWriterPass.h"
  27 #include "llvm/CodeGen/RegAllocRegistry.h"
  28 #include "llvm/CodeGen/SchedulerRegistry.h"
  29 #include "llvm/IR/DataLayout.h"
  30 #include "llvm/IR/IRPrintingPasses.h"
  31 #include "llvm/IR/LegacyPassManager.h"
  32 #include "llvm/IR/Module.h"
  33 #include "llvm/IR/ModuleSummaryIndex.h"
  34 #include "llvm/IR/Verifier.h"
  35 #include "llvm/LTO/LTOBackend.h"
  36 #include "llvm/MC/MCAsmInfo.h"
  37 #include "llvm/MC/SubtargetFeature.h"
  38 #include "llvm/Passes/PassBuilder.h"
  39 #include "llvm/Support/CommandLine.h"
  40 #include "llvm/Support/MemoryBuffer.h"
  41 #include "llvm/Support/PrettyStackTrace.h"
  42 #include "llvm/Support/TargetRegistry.h"
  43 #include "llvm/Support/Timer.h"
  44 #include "llvm/Support/raw_ostream.h"
  45 #include "llvm/Target/TargetMachine.h"
  46 #include "llvm/Target/TargetOptions.h"
  47 #include "llvm/Target/TargetSubtargetInfo.h"
  48 #include "llvm/Transforms/Coroutines.h"
  49 #include "llvm/Transforms/IPO.h"
  50 #include "llvm/Transforms/IPO/AlwaysInliner.h"
  51 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
  52 #include "llvm/Transforms/IPO/ThinLTOBitcodeWriter.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/NameAnonGlobals.h"
  58 #include "llvm/Transforms/Utils/SymbolRewriter.h"
  59 #include <memory>
  60 using namespace clang;
  61 using namespace llvm;
  62
  63 namespace {
  64
  65 // Default filename used for profile generation.
  66 static constexpr StringLiteral DefaultProfileGenName = "default_%m.profraw";
  67
  68 class EmitAssemblyHelper {
  69   DiagnosticsEngine &Diags;
  70   const HeaderSearchOptions &HSOpts;
  71   const CodeGenOptions &CodeGenOpts;
  72   const clang::TargetOptions &TargetOpts;
  73   const LangOptions &LangOpts;
  74   Module *TheModule;
  75
  76   Timer CodeGenerationTime;
  77
  78   std::unique_ptr<raw_pwrite_stream> OS;
  79
  80   TargetIRAnalysis getTargetIRAnalysis() const {
  81     if (TM)
  82       return TM->getTargetIRAnalysis();
  83
  84     return TargetIRAnalysis();
  85   }
  86
  87   void CreatePasses(legacy::PassManager &MPM, legacy::FunctionPassManager &FPM);
  88
  89   /// Generates the TargetMachine.
  90   /// Leaves TM unchanged if it is unable to create the target machine.
  91   /// Some of our clang tests specify triples which are not built
  92   /// into clang. This is okay because these tests check the generated
  93   /// IR, and they require DataLayout which depends on the triple.
  94   /// In this case, we allow this method to fail and not report an error.
  95   /// When MustCreateTM is used, we print an error if we are unable to load
  96   /// the requested target.
  97   void CreateTargetMachine(bool MustCreateTM);
  98
  99   /// Add passes necessary to emit assembly or LLVM IR.
 100   ///
 101   /// \return True on success.
 102   bool AddEmitPasses(legacy::PassManager &CodeGenPasses, BackendAction Action,
 103                      raw_pwrite_stream &OS);
 104
 105 public:
 106   EmitAssemblyHelper(DiagnosticsEngine &_Diags,
 107                      const HeaderSearchOptions &HeaderSearchOpts,
 108                      const CodeGenOptions &CGOpts,
 109                      const clang::TargetOptions &TOpts,
 110                      const LangOptions &LOpts, Module *M)
 111       : Diags(_Diags), HSOpts(HeaderSearchOpts), CodeGenOpts(CGOpts),
 112         TargetOpts(TOpts), LangOpts(LOpts), TheModule(M),
 113         CodeGenerationTime("codegen", "Code Generation Time") {}
 114
 115   ~EmitAssemblyHelper() {
 116     if (CodeGenOpts.DisableFree)
 117       BuryPointer(std::move(TM));
 118   }
 119
 120   std::unique_ptr<TargetMachine> TM;
 121
 122   void EmitAssembly(BackendAction Action,
 123                     std::unique_ptr<raw_pwrite_stream> OS);
 124
 125   void EmitAssemblyWithNewPassManager(BackendAction Action,
 126                                       std::unique_ptr<raw_pwrite_stream> OS);
 127 };
 128
 129 // We need this wrapper to access LangOpts and CGOpts from extension functions
 130 // that we add to the PassManagerBuilder.
 131 class PassManagerBuilderWrapper : public PassManagerBuilder {
 132 public:
 133   PassManagerBuilderWrapper(const Triple &TargetTriple,
 134                             const CodeGenOptions &CGOpts,
 135                             const LangOptions &LangOpts)
 136       : PassManagerBuilder(), TargetTriple(TargetTriple), CGOpts(CGOpts),
 137         LangOpts(LangOpts) {}
 138   const Triple &getTargetTriple() const { return TargetTriple; }
 139   const CodeGenOptions &getCGOpts() const { return CGOpts; }
 140   const LangOptions &getLangOpts() const { return LangOpts; }
 141
 142 private:
 143   const Triple &TargetTriple;
 144   const CodeGenOptions &CGOpts;
 145   const LangOptions &LangOpts;
 146 };
 147 }
 148
 149 static void addObjCARCAPElimPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
 150   if (Builder.OptLevel > 0)
 151     PM.add(createObjCARCAPElimPass());
 152 }
 153
 154 static void addObjCARCExpandPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
 155   if (Builder.OptLevel > 0)
 156     PM.add(createObjCARCExpandPass());
 157 }
 158
 159 static void addObjCARCOptPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
 160   if (Builder.OptLevel > 0)
 161     PM.add(createObjCARCOptPass());
 162 }
 163
 164 static void addAddDiscriminatorsPass(const PassManagerBuilder &Builder,
 165                                      legacy::PassManagerBase &PM) {
 166   PM.add(createAddDiscriminatorsPass());
 167 }
 168
 169 static void addBoundsCheckingPass(const PassManagerBuilder &Builder,
 170                                   legacy::PassManagerBase &PM) {
 171   PM.add(createBoundsCheckingPass());
 172 }
 173
 174 static void addSanitizerCoveragePass(const PassManagerBuilder &Builder,
 175                                      legacy::PassManagerBase &PM) {
 176   const PassManagerBuilderWrapper &BuilderWrapper =
 177       static_cast<const PassManagerBuilderWrapper&>(Builder);
 178   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
 179   SanitizerCoverageOptions Opts;
 180   Opts.CoverageType =
 181       static_cast<SanitizerCoverageOptions::Type>(CGOpts.SanitizeCoverageType);
 182   Opts.IndirectCalls = CGOpts.SanitizeCoverageIndirectCalls;
 183   Opts.TraceBB = CGOpts.SanitizeCoverageTraceBB;
 184   Opts.TraceCmp = CGOpts.SanitizeCoverageTraceCmp;
 185   Opts.TraceDiv = CGOpts.SanitizeCoverageTraceDiv;
 186   Opts.TraceGep = CGOpts.SanitizeCoverageTraceGep;
 187   Opts.Use8bitCounters = CGOpts.SanitizeCoverage8bitCounters;
 188   Opts.TracePC = CGOpts.SanitizeCoverageTracePC;
 189   Opts.TracePCGuard = CGOpts.SanitizeCoverageTracePCGuard;
 190   Opts.NoPrune = CGOpts.SanitizeCoverageNoPrune;
 191   Opts.Inline8bitCounters = CGOpts.SanitizeCoverageInline8bitCounters;
 192   PM.add(createSanitizerCoverageModulePass(Opts));
 193 }
 194
 195 // Check if ASan should use GC-friendly instrumentation for globals.
 196 // First of all, there is no point if -fdata-sections is off (expect for MachO,
 197 // where this is not a factor). Also, on ELF this feature requires an assembler
 198 // extension that only works with -integrated-as at the moment.
 199 static bool asanUseGlobalsGC(const Triple &T, const CodeGenOptions &CGOpts) {
 200   if (!CGOpts.SanitizeAddressGlobalsDeadStripping)
 201     return false;
 202   switch (T.getObjectFormat()) {
 203   case Triple::MachO:
 204   case Triple::COFF:
 205     return true;
 206   case Triple::ELF:
 207     return CGOpts.DataSections && !CGOpts.DisableIntegratedAS;
 208   default:
 209     return false;
 210   }
 211 }
 212
 213 static void addAddressSanitizerPasses(const PassManagerBuilder &Builder,
 214                                       legacy::PassManagerBase &PM) {
 215   const PassManagerBuilderWrapper &BuilderWrapper =
 216       static_cast<const PassManagerBuilderWrapper&>(Builder);
 217   const Triple &T = BuilderWrapper.getTargetTriple();
 218   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
 219   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Address);
 220   bool UseAfterScope = CGOpts.SanitizeAddressUseAfterScope;
 221   bool UseGlobalsGC = asanUseGlobalsGC(T, CGOpts);
 222   PM.add(createAddressSanitizerFunctionPass(/*CompileKernel*/ false, Recover,
 223                                             UseAfterScope));
 224   PM.add(createAddressSanitizerModulePass(/*CompileKernel*/ false, Recover,
 225                                           UseGlobalsGC));
 226 }
 227
 228 static void addKernelAddressSanitizerPasses(const PassManagerBuilder &Builder,
 229                                             legacy::PassManagerBase &PM) {
 230   PM.add(createAddressSanitizerFunctionPass(
 231       /*CompileKernel*/ true,
 232       /*Recover*/ true, /*UseAfterScope*/ false));
 233   PM.add(createAddressSanitizerModulePass(/*CompileKernel*/true,
 234                                           /*Recover*/true));
 235 }
 236
 237 static void addMemorySanitizerPass(const PassManagerBuilder &Builder,
 238                                    legacy::PassManagerBase &PM) {
 239   const PassManagerBuilderWrapper &BuilderWrapper =
 240       static_cast<const PassManagerBuilderWrapper&>(Builder);
 241   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
 242   int TrackOrigins = CGOpts.SanitizeMemoryTrackOrigins;
 243   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Memory);
 244   PM.add(createMemorySanitizerPass(TrackOrigins, Recover));
 245
 246   // MemorySanitizer inserts complex instrumentation that mostly follows
 247   // the logic of the original code, but operates on "shadow" values.
 248   // It can benefit from re-running some general purpose optimization passes.
 249   if (Builder.OptLevel > 0) {
 250     PM.add(createEarlyCSEPass());
 251     PM.add(createReassociatePass());
 252     PM.add(createLICMPass());
 253     PM.add(createGVNPass());
 254     PM.add(createInstructionCombiningPass());
 255     PM.add(createDeadStoreEliminationPass());
 256   }
 257 }
 258
 259 static void addThreadSanitizerPass(const PassManagerBuilder &Builder,
 260                                    legacy::PassManagerBase &PM) {
 261   PM.add(createThreadSanitizerPass());
 262 }
 263
 264 static void addDataFlowSanitizerPass(const PassManagerBuilder &Builder,
 265                                      legacy::PassManagerBase &PM) {
 266   const PassManagerBuilderWrapper &BuilderWrapper =
 267       static_cast<const PassManagerBuilderWrapper&>(Builder);
 268   const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
 269   PM.add(createDataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
 270 }
 271
 272 static void addEfficiencySanitizerPass(const PassManagerBuilder &Builder,
 273                                        legacy::PassManagerBase &PM) {
 274   const PassManagerBuilderWrapper &BuilderWrapper =
 275       static_cast<const PassManagerBuilderWrapper&>(Builder);
 276   const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
 277   EfficiencySanitizerOptions Opts;
 278   if (LangOpts.Sanitize.has(SanitizerKind::EfficiencyCacheFrag))
 279     Opts.ToolType = EfficiencySanitizerOptions::ESAN_CacheFrag;
 280   else if (LangOpts.Sanitize.has(SanitizerKind::EfficiencyWorkingSet))
 281     Opts.ToolType = EfficiencySanitizerOptions::ESAN_WorkingSet;
 282   PM.add(createEfficiencySanitizerPass(Opts));
 283 }
 284
 285 static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
 286                                          const CodeGenOptions &CodeGenOpts) {
 287   TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple);
 288   if (!CodeGenOpts.SimplifyLibCalls)
 289     TLII->disableAllFunctions();
 290   else {
 291     // Disable individual libc/libm calls in TargetLibraryInfo.
 292     LibFunc F;
 293     for (auto &FuncName : CodeGenOpts.getNoBuiltinFuncs())
 294       if (TLII->getLibFunc(FuncName, F))
 295         TLII->setUnavailable(F);
 296   }
 297
 298   switch (CodeGenOpts.getVecLib()) {
 299   case CodeGenOptions::Accelerate:
 300     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::Accelerate);
 301     break;
 302   case CodeGenOptions::SVML:
 303     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::SVML);
 304     break;
 305   default:
 306     break;
 307   }
 308   return TLII;
 309 }
 310
 311 static void addSymbolRewriterPass(const CodeGenOptions &Opts,
 312                                   legacy::PassManager *MPM) {
 313   llvm::SymbolRewriter::RewriteDescriptorList DL;
 314
 315   llvm::SymbolRewriter::RewriteMapParser MapParser;
 316   for (const auto &MapFile : Opts.RewriteMapFiles)
 317     MapParser.parse(MapFile, &DL);
 318
 319   MPM->add(createRewriteSymbolsPass(DL));
 320 }
 321
 322 static CodeGenOpt::Level getCGOptLevel(const CodeGenOptions &CodeGenOpts) {
 323   switch (CodeGenOpts.OptimizationLevel) {
 324   default:
 325     llvm_unreachable("Invalid optimization level!");
 326   case 0:
 327     return CodeGenOpt::None;
 328   case 1:
 329     return CodeGenOpt::Less;
 330   case 2:
 331     return CodeGenOpt::Default; // O2/Os/Oz
 332   case 3:
 333     return CodeGenOpt::Aggressive;
 334   }
 335 }
 336
 337 static llvm::CodeModel::Model getCodeModel(const CodeGenOptions &CodeGenOpts) {
 338   unsigned CodeModel =
 339       llvm::StringSwitch<unsigned>(CodeGenOpts.CodeModel)
 340       .Case("small", llvm::CodeModel::Small)
 341       .Case("kernel", llvm::CodeModel::Kernel)
 342       .Case("medium", llvm::CodeModel::Medium)
 343       .Case("large", llvm::CodeModel::Large)
 344       .Case("default", llvm::CodeModel::Default)
 345       .Default(~0u);
 346   assert(CodeModel != ~0u && "invalid code model!");
 347   return static_cast<llvm::CodeModel::Model>(CodeModel);
 348 }
 349
 350 static llvm::Reloc::Model getRelocModel(const CodeGenOptions &CodeGenOpts) {
 351   // Keep this synced with the equivalent code in
 352   // lib/Frontend/CompilerInvocation.cpp
 353   llvm::Optional<llvm::Reloc::Model> RM;
 354   RM = llvm::StringSwitch<llvm::Reloc::Model>(CodeGenOpts.RelocationModel)
 355       .Case("static", llvm::Reloc::Static)
 356       .Case("pic", llvm::Reloc::PIC_)
 357       .Case("ropi", llvm::Reloc::ROPI)
 358       .Case("rwpi", llvm::Reloc::RWPI)
 359       .Case("ropi-rwpi", llvm::Reloc::ROPI_RWPI)
 360       .Case("dynamic-no-pic", llvm::Reloc::DynamicNoPIC);
 361   assert(RM.hasValue() && "invalid PIC model!");
 362   return *RM;
 363 }
 364
 365 static TargetMachine::CodeGenFileType getCodeGenFileType(BackendAction Action) {
 366   if (Action == Backend_EmitObj)
 367     return TargetMachine::CGFT_ObjectFile;
 368   else if (Action == Backend_EmitMCNull)
 369     return TargetMachine::CGFT_Null;
 370   else {
 371     assert(Action == Backend_EmitAssembly && "Invalid action!");
 372     return TargetMachine::CGFT_AssemblyFile;
 373   }
 374 }
 375
 376 static void initTargetOptions(llvm::TargetOptions &Options,
 377                               const CodeGenOptions &CodeGenOpts,
 378                               const clang::TargetOptions &TargetOpts,
 379                               const LangOptions &LangOpts,
 380                               const HeaderSearchOptions &HSOpts) {
 381   Options.ThreadModel =
 382       llvm::StringSwitch<llvm::ThreadModel::Model>(CodeGenOpts.ThreadModel)
 383           .Case("posix", llvm::ThreadModel::POSIX)
 384           .Case("single", llvm::ThreadModel::Single);
 385
 386   // Set float ABI type.
 387   assert((CodeGenOpts.FloatABI == "soft" || CodeGenOpts.FloatABI == "softfp" ||
 388           CodeGenOpts.FloatABI == "hard" || CodeGenOpts.FloatABI.empty()) &&
 389          "Invalid Floating Point ABI!");
 390   Options.FloatABIType =
 391       llvm::StringSwitch<llvm::FloatABI::ABIType>(CodeGenOpts.FloatABI)
 392           .Case("soft", llvm::FloatABI::Soft)
 393           .Case("softfp", llvm::FloatABI::Soft)
 394           .Case("hard", llvm::FloatABI::Hard)
 395           .Default(llvm::FloatABI::Default);
 396
 397   // Set FP fusion mode.
 398   switch (LangOpts.getDefaultFPContractMode()) {
 399   case LangOptions::FPC_Off:
 400     // Preserve any contraction performed by the front-end.  (Strict performs
 401     // splitting of the muladd instrinsic in the backend.)
 402     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
 403     break;
 404   case LangOptions::FPC_On:
 405     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
 406     break;
 407   case LangOptions::FPC_Fast:
 408     Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
 409     break;
 410   }
 411
 412   Options.UseInitArray = CodeGenOpts.UseInitArray;
 413   Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
 414   Options.CompressDebugSections = CodeGenOpts.getCompressDebugSections();
 415   Options.RelaxELFRelocations = CodeGenOpts.RelaxELFRelocations;
 416
 417   // Set EABI version.
 418   Options.EABIVersion = TargetOpts.EABIVersion;
 419
 420   if (LangOpts.SjLjExceptions)
 421     Options.ExceptionModel = llvm::ExceptionHandling::SjLj;
 422
 423   Options.NoInfsFPMath = CodeGenOpts.NoInfsFPMath;
 424   Options.NoNaNsFPMath = CodeGenOpts.NoNaNsFPMath;
 425   Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
 426   Options.UnsafeFPMath = CodeGenOpts.UnsafeFPMath;
 427   Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
 428   Options.FunctionSections = CodeGenOpts.FunctionSections;
 429   Options.DataSections = CodeGenOpts.DataSections;
 430   Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
 431   Options.EmulatedTLS = CodeGenOpts.EmulatedTLS;
 432   Options.DebuggerTuning = CodeGenOpts.getDebuggerTuning();
 433
 434   if (CodeGenOpts.EnableSplitDwarf)
 435     Options.MCOptions.SplitDwarfFile = CodeGenOpts.SplitDwarfFile;
 436   Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
 437   Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
 438   Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
 439   Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
 440   Options.MCOptions.MCIncrementalLinkerCompatible =
 441       CodeGenOpts.IncrementalLinkerCompatible;
 442   Options.MCOptions.MCPIECopyRelocations = CodeGenOpts.PIECopyRelocations;
 443   Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
 444   Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
 445   Options.MCOptions.PreserveAsmComments = CodeGenOpts.PreserveAsmComments;
 446   Options.MCOptions.ABIName = TargetOpts.ABI;
 447   for (const auto &Entry : HSOpts.UserEntries)
 448     if (!Entry.IsFramework &&
 449         (Entry.Group == frontend::IncludeDirGroup::Quoted ||
 450          Entry.Group == frontend::IncludeDirGroup::Angled ||
 451          Entry.Group == frontend::IncludeDirGroup::System))
 452       Options.MCOptions.IASSearchPaths.push_back(
 453           Entry.IgnoreSysRoot ? Entry.Path : HSOpts.Sysroot + Entry.Path);
 454 }
 455
 456 void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
 457                                       legacy::FunctionPassManager &FPM) {
 458   // Handle disabling of all LLVM passes, where we want to preserve the
 459   // internal module before any optimization.
 460   if (CodeGenOpts.DisableLLVMPasses)
 461     return;
 462
 463   // Figure out TargetLibraryInfo.  This needs to be added to MPM and FPM
 464   // manually (and not via PMBuilder), since some passes (eg. InstrProfiling)
 465   // are inserted before PMBuilder ones - they'd get the default-constructed
 466   // TLI with an unknown target otherwise.
 467   Triple TargetTriple(TheModule->getTargetTriple());
 468   std::unique_ptr<TargetLibraryInfoImpl> TLII(
 469       createTLII(TargetTriple, CodeGenOpts));
 470
 471   PassManagerBuilderWrapper PMBuilder(TargetTriple, CodeGenOpts, LangOpts);
 472
 473   // At O0 and O1 we only run the always inliner which is more efficient. At
 474   // higher optimization levels we run the normal inliner.
 475   if (CodeGenOpts.OptimizationLevel <= 1) {
 476     bool InsertLifetimeIntrinsics = (CodeGenOpts.OptimizationLevel != 0 &&
 477                                      !CodeGenOpts.DisableLifetimeMarkers);
 478     PMBuilder.Inliner = createAlwaysInlinerLegacyPass(InsertLifetimeIntrinsics);
 479   } else {
 480     // We do not want to inline hot callsites for SamplePGO module-summary build
 481     // because profile annotation will happen again in ThinLTO backend, and we
 482     // want the IR of the hot path to match the profile.
 483     PMBuilder.Inliner = createFunctionInliningPass(
 484         CodeGenOpts.OptimizationLevel, CodeGenOpts.OptimizeSize,
 485         (!CodeGenOpts.SampleProfileFile.empty() &&
 486          CodeGenOpts.EmitSummaryIndex));
 487   }
 488
 489   PMBuilder.OptLevel = CodeGenOpts.OptimizationLevel;
 490   PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
 491   PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
 492   PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
 493
 494   PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
 495   PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
 496   PMBuilder.PrepareForThinLTO = CodeGenOpts.EmitSummaryIndex;
 497   PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
 498   PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
 499
 500   MPM.add(new TargetLibraryInfoWrapperPass(*TLII));
 501
 502   if (TM)
 503     TM->adjustPassManager(PMBuilder);
 504
 505   if (CodeGenOpts.DebugInfoForProfiling ||
 506       !CodeGenOpts.SampleProfileFile.empty())
 507     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
 508                            addAddDiscriminatorsPass);
 509
 510   // In ObjC ARC mode, add the main ARC optimization passes.
 511   if (LangOpts.ObjCAutoRefCount) {
 512     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
 513                            addObjCARCExpandPass);
 514     PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
 515                            addObjCARCAPElimPass);
 516     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
 517                            addObjCARCOptPass);
 518   }
 519
 520   if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds)) {
 521     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
 522                            addBoundsCheckingPass);
 523     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 524                            addBoundsCheckingPass);
 525   }
 526
 527   if (CodeGenOpts.SanitizeCoverageType ||
 528       CodeGenOpts.SanitizeCoverageIndirectCalls ||
 529       CodeGenOpts.SanitizeCoverageTraceCmp) {
 530     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 531                            addSanitizerCoveragePass);
 532     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 533                            addSanitizerCoveragePass);
 534   }
 535
 536   if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
 537     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 538                            addAddressSanitizerPasses);
 539     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 540                            addAddressSanitizerPasses);
 541   }
 542
 543   if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
 544     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 545                            addKernelAddressSanitizerPasses);
 546     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 547                            addKernelAddressSanitizerPasses);
 548   }
 549
 550   if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
 551     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 552                            addMemorySanitizerPass);
 553     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 554                            addMemorySanitizerPass);
 555   }
 556
 557   if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
 558     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 559                            addThreadSanitizerPass);
 560     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 561                            addThreadSanitizerPass);
 562   }
 563
 564   if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
 565     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 566                            addDataFlowSanitizerPass);
 567     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 568                            addDataFlowSanitizerPass);
 569   }
 570
 571   if (LangOpts.CoroutinesTS)
 572     addCoroutinePassesToExtensionPoints(PMBuilder);
 573
 574   if (LangOpts.Sanitize.hasOneOf(SanitizerKind::Efficiency)) {
 575     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
 576                            addEfficiencySanitizerPass);
 577     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
 578                            addEfficiencySanitizerPass);
 579   }
 580
 581   // Set up the per-function pass manager.
 582   FPM.add(new TargetLibraryInfoWrapperPass(*TLII));
 583   if (CodeGenOpts.VerifyModule)
 584     FPM.add(createVerifierPass());
 585
 586   // Set up the per-module pass manager.
 587   if (!CodeGenOpts.RewriteMapFiles.empty())
 588     addSymbolRewriterPass(CodeGenOpts, &MPM);
 589
 590   if (!CodeGenOpts.DisableGCov &&
 591       (CodeGenOpts.EmitGcovArcs || CodeGenOpts.EmitGcovNotes)) {
 592     // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
 593     // LLVM's -default-gcov-version flag is set to something invalid.
 594     GCOVOptions Options;
 595     Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
 596     Options.EmitData = CodeGenOpts.EmitGcovArcs;
 597     memcpy(Options.Version, CodeGenOpts.CoverageVersion, 4);
 598     Options.UseCfgChecksum = CodeGenOpts.CoverageExtraChecksum;
 599     Options.NoRedZone = CodeGenOpts.DisableRedZone;
 600     Options.FunctionNamesInData =
 601         !CodeGenOpts.CoverageNoFunctionNamesInData;
 602     Options.ExitBlockBeforeBody = CodeGenOpts.CoverageExitBlockBeforeBody;
 603     MPM.add(createGCOVProfilerPass(Options));
 604     if (CodeGenOpts.getDebugInfo() == codegenoptions::NoDebugInfo)
 605       MPM.add(createStripSymbolsPass(true));
 606   }
 607
 608   if (CodeGenOpts.hasProfileClangInstr()) {
 609     InstrProfOptions Options;
 610     Options.NoRedZone = CodeGenOpts.DisableRedZone;
 611     Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
 612     MPM.add(createInstrProfilingLegacyPass(Options));
 613   }
 614   if (CodeGenOpts.hasProfileIRInstr()) {
 615     PMBuilder.EnablePGOInstrGen = true;
 616     if (!CodeGenOpts.InstrProfileOutput.empty())
 617       PMBuilder.PGOInstrGen = CodeGenOpts.InstrProfileOutput;
 618     else
 619       PMBuilder.PGOInstrGen = DefaultProfileGenName;
 620   }
 621   if (CodeGenOpts.hasProfileIRUse())
 622     PMBuilder.PGOInstrUse = CodeGenOpts.ProfileInstrumentUsePath;
 623
 624   if (!CodeGenOpts.SampleProfileFile.empty())
 625     PMBuilder.PGOSampleUse = CodeGenOpts.SampleProfileFile;
 626
 627   PMBuilder.populateFunctionPassManager(FPM);
 628   PMBuilder.populateModulePassManager(MPM);
 629 }
 630
 631 static void setCommandLineOpts(const CodeGenOptions &CodeGenOpts) {
 632   SmallVector<const char *, 16> BackendArgs;
 633   BackendArgs.push_back("clang"); // Fake program name.
 634   if (!CodeGenOpts.DebugPass.empty()) {
 635     BackendArgs.push_back("-debug-pass");
 636     BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
 637   }
 638   if (!CodeGenOpts.LimitFloatPrecision.empty()) {
 639     BackendArgs.push_back("-limit-float-precision");
 640     BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
 641   }
 642   for (const std::string &BackendOption : CodeGenOpts.BackendOptions)
 643     BackendArgs.push_back(BackendOption.c_str());
 644   BackendArgs.push_back(nullptr);
 645   llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
 646                                     BackendArgs.data());
 647 }
 648
 649 void EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
 650   // Create the TargetMachine for generating code.
 651   std::string Error;
 652   std::string Triple = TheModule->getTargetTriple();
 653   const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
 654   if (!TheTarget) {
 655     if (MustCreateTM)
 656       Diags.Report(diag::err_fe_unable_to_create_target) << Error;
 657     return;
 658   }
 659
 660   llvm::CodeModel::Model CM  = getCodeModel(CodeGenOpts);
 661   std::string FeaturesStr =
 662       llvm::join(TargetOpts.Features.begin(), TargetOpts.Features.end(), ",");
 663   llvm::Reloc::Model RM = getRelocModel(CodeGenOpts);
 664   CodeGenOpt::Level OptLevel = getCGOptLevel(CodeGenOpts);
 665
 666   llvm::TargetOptions Options;
 667   initTargetOptions(Options, CodeGenOpts, TargetOpts, LangOpts, HSOpts);
 668   TM.reset(TheTarget->createTargetMachine(Triple, TargetOpts.CPU, FeaturesStr,
 669                                           Options, RM, CM, OptLevel));
 670 }
 671
 672 bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
 673                                        BackendAction Action,
 674                                        raw_pwrite_stream &OS) {
 675   // Add LibraryInfo.
 676   llvm::Triple TargetTriple(TheModule->getTargetTriple());
 677   std::unique_ptr<TargetLibraryInfoImpl> TLII(
 678       createTLII(TargetTriple, CodeGenOpts));
 679   CodeGenPasses.add(new TargetLibraryInfoWrapperPass(*TLII));
 680
 681   // Normal mode, emit a .s or .o file by running the code generator. Note,
 682   // this also adds codegenerator level optimization passes.
 683   TargetMachine::CodeGenFileType CGFT = getCodeGenFileType(Action);
 684
 685   // Add ObjC ARC final-cleanup optimizations. This is done as part of the
 686   // "codegen" passes so that it isn't run multiple times when there is
 687   // inlining happening.
 688   if (CodeGenOpts.OptimizationLevel > 0)
 689     CodeGenPasses.add(createObjCARCContractPass());
 690
 691   if (TM->addPassesToEmitFile(CodeGenPasses, OS, CGFT,
 692                               /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
 693     Diags.Report(diag::err_fe_unable_to_interface_with_target);
 694     return false;
 695   }
 696
 697   return true;
 698 }
 699
 700 void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
 701                                       std::unique_ptr<raw_pwrite_stream> OS) {
 702   TimeRegion Region(llvm::TimePassesIsEnabled ? &CodeGenerationTime : nullptr);
 703
 704   setCommandLineOpts(CodeGenOpts);
 705
 706   bool UsesCodeGen = (Action != Backend_EmitNothing &&
 707                       Action != Backend_EmitBC &&
 708                       Action != Backend_EmitLL);
 709   CreateTargetMachine(UsesCodeGen);
 710
 711   if (UsesCodeGen && !TM)
 712     return;
 713   if (TM)
 714     TheModule->setDataLayout(TM->createDataLayout());
 715
 716   legacy::PassManager PerModulePasses;
 717   PerModulePasses.add(
 718       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
 719
 720   legacy::FunctionPassManager PerFunctionPasses(TheModule);
 721   PerFunctionPasses.add(
 722       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
 723
 724   CreatePasses(PerModulePasses, PerFunctionPasses);
 725
 726   legacy::PassManager CodeGenPasses;
 727   CodeGenPasses.add(
 728       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
 729
 730   std::unique_ptr<raw_fd_ostream> ThinLinkOS;
 731
 732   switch (Action) {
 733   case Backend_EmitNothing:
 734     break;
 735
 736   case Backend_EmitBC:
 737     if (CodeGenOpts.EmitSummaryIndex) {
 738       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
 739         std::error_code EC;
 740         ThinLinkOS.reset(new llvm::raw_fd_ostream(
 741             CodeGenOpts.ThinLinkBitcodeFile, EC,
 742             llvm::sys::fs::F_None));
 743         if (EC) {
 744           Diags.Report(diag::err_fe_unable_to_open_output) << CodeGenOpts.ThinLinkBitcodeFile
 745                                                            << EC.message();
 746           return;
 747         }
 748       }
 749       PerModulePasses.add(
 750           createWriteThinLTOBitcodePass(*OS, ThinLinkOS.get()));
 751     }
 752     else
 753       PerModulePasses.add(
 754           createBitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists));
 755     break;
 756
 757   case Backend_EmitLL:
 758     PerModulePasses.add(
 759         createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
 760     break;
 761
 762   default:
 763     if (!AddEmitPasses(CodeGenPasses, Action, *OS))
 764       return;
 765   }
 766
 767   // Before executing passes, print the final values of the LLVM options.
 768   cl::PrintOptionValues();
 769
 770   // Run passes. For now we do all passes at once, but eventually we
 771   // would like to have the option of streaming code generation.
 772
 773   {
 774     PrettyStackTraceString CrashInfo("Per-function optimization");
 775
 776     PerFunctionPasses.doInitialization();
 777     for (Function &F : *TheModule)
 778       if (!F.isDeclaration())
 779         PerFunctionPasses.run(F);
 780     PerFunctionPasses.doFinalization();
 781   }
 782
 783   {
 784     PrettyStackTraceString CrashInfo("Per-module optimization passes");
 785     PerModulePasses.run(*TheModule);
 786   }
 787
 788   {
 789     PrettyStackTraceString CrashInfo("Code generation");
 790     CodeGenPasses.run(*TheModule);
 791   }
 792 }
 793
 794 static PassBuilder::OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
 795   switch (Opts.OptimizationLevel) {
 796   default:
 797     llvm_unreachable("Invalid optimization level!");
 798
 799   case 1:
 800     return PassBuilder::O1;
 801
 802   case 2:
 803     switch (Opts.OptimizeSize) {
 804     default:
 805       llvm_unreachable("Invalide optimization level for size!");
 806
 807     case 0:
 808       return PassBuilder::O2;
 809
 810     case 1:
 811       return PassBuilder::Os;
 812
 813     case 2:
 814       return PassBuilder::Oz;
 815     }
 816
 817   case 3:
 818     return PassBuilder::O3;
 819   }
 820 }
 821
 822 /// A clean version of `EmitAssembly` that uses the new pass manager.
 823 ///
 824 /// Not all features are currently supported in this system, but where
 825 /// necessary it falls back to the legacy pass manager to at least provide
 826 /// basic functionality.
 827 ///
 828 /// This API is planned to have its functionality finished and then to replace
 829 /// `EmitAssembly` at some point in the future when the default switches.
 830 void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
 831     BackendAction Action, std::unique_ptr<raw_pwrite_stream> OS) {
 832   TimeRegion Region(llvm::TimePassesIsEnabled ? &CodeGenerationTime : nullptr);
 833   setCommandLineOpts(CodeGenOpts);
 834
 835   // The new pass manager always makes a target machine available to passes
 836   // during construction.
 837   CreateTargetMachine(/*MustCreateTM*/ true);
 838   if (!TM)
 839     // This will already be diagnosed, just bail.
 840     return;
 841   TheModule->setDataLayout(TM->createDataLayout());
 842
 843   PGOOptions PGOOpt;
 844
 845   // -fprofile-generate.
 846   PGOOpt.RunProfileGen = CodeGenOpts.hasProfileIRInstr();
 847   if (PGOOpt.RunProfileGen)
 848     PGOOpt.ProfileGenFile = CodeGenOpts.InstrProfileOutput.empty() ?
 849       DefaultProfileGenName : CodeGenOpts.InstrProfileOutput;
 850
 851   // -fprofile-use.
 852   if (CodeGenOpts.hasProfileIRUse())
 853     PGOOpt.ProfileUseFile = CodeGenOpts.ProfileInstrumentUsePath;
 854
 855   if (!CodeGenOpts.SampleProfileFile.empty())
 856     PGOOpt.SampleProfileFile = CodeGenOpts.SampleProfileFile;
 857
 858   // Only pass a PGO options struct if -fprofile-generate or
 859   // -fprofile-use were passed on the cmdline.
 860   PassBuilder PB(TM.get(),
 861     (PGOOpt.RunProfileGen ||
 862       !PGOOpt.ProfileUseFile.empty() ||
 863       !PGOOpt.SampleProfileFile.empty()) ?
 864         Optional<PGOOptions>(PGOOpt) : None);
 865
 866   LoopAnalysisManager LAM;
 867   FunctionAnalysisManager FAM;
 868   CGSCCAnalysisManager CGAM;
 869   ModuleAnalysisManager MAM;
 870
 871   // Register the AA manager first so that our version is the one used.
 872   FAM.registerPass([&] { return PB.buildDefaultAAPipeline(); });
 873
 874   // Register all the basic analyses with the managers.
 875   PB.registerModuleAnalyses(MAM);
 876   PB.registerCGSCCAnalyses(CGAM);
 877   PB.registerFunctionAnalyses(FAM);
 878   PB.registerLoopAnalyses(LAM);
 879   PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
 880
 881   ModulePassManager MPM(CodeGenOpts.DebugPassManager);
 882
 883   if (!CodeGenOpts.DisableLLVMPasses) {
 884     bool IsThinLTO = CodeGenOpts.EmitSummaryIndex;
 885     bool IsLTO = CodeGenOpts.PrepareForLTO;
 886
 887     if (CodeGenOpts.OptimizationLevel == 0) {
 888       // Build a minimal pipeline based on the semantics required by Clang,
 889       // which is just that always inlining occurs.
 890       MPM.addPass(AlwaysInlinerPass());
 891       if (IsThinLTO)
 892         MPM.addPass(NameAnonGlobalPass());
 893     } else {
 894       // Map our optimization levels into one of the distinct levels used to
 895       // configure the pipeline.
 896       PassBuilder::OptimizationLevel Level = mapToLevel(CodeGenOpts);
 897
 898       if (IsThinLTO) {
 899         MPM = PB.buildThinLTOPreLinkDefaultPipeline(
 900             Level, CodeGenOpts.DebugPassManager);
 901         MPM.addPass(NameAnonGlobalPass());
 902       } else if (IsLTO) {
 903         MPM = PB.buildLTOPreLinkDefaultPipeline(Level,
 904                                                 CodeGenOpts.DebugPassManager);
 905       } else {
 906         MPM = PB.buildPerModuleDefaultPipeline(Level,
 907                                                CodeGenOpts.DebugPassManager);
 908       }
 909     }
 910   }
 911
 912   // FIXME: We still use the legacy pass manager to do code generation. We
 913   // create that pass manager here and use it as needed below.
 914   legacy::PassManager CodeGenPasses;
 915   bool NeedCodeGen = false;
 916   Optional<raw_fd_ostream> ThinLinkOS;
 917
 918   // Append any output we need to the pass manager.
 919   switch (Action) {
 920   case Backend_EmitNothing:
 921     break;
 922
 923   case Backend_EmitBC:
 924     if (CodeGenOpts.EmitSummaryIndex) {
 925       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
 926         std::error_code EC;
 927         ThinLinkOS.emplace(CodeGenOpts.ThinLinkBitcodeFile, EC,
 928                            llvm::sys::fs::F_None);
 929         if (EC) {
 930           Diags.Report(diag::err_fe_unable_to_open_output)
 931               << CodeGenOpts.ThinLinkBitcodeFile << EC.message();
 932           return;
 933         }
 934       }
 935       MPM.addPass(
 936           ThinLTOBitcodeWriterPass(*OS, ThinLinkOS ? &*ThinLinkOS : nullptr));
 937     } else {
 938       MPM.addPass(BitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists,
 939                                     CodeGenOpts.EmitSummaryIndex,
 940                                     CodeGenOpts.EmitSummaryIndex));
 941     }
 942     break;
 943
 944   case Backend_EmitLL:
 945     MPM.addPass(PrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
 946     break;
 947
 948   case Backend_EmitAssembly:
 949   case Backend_EmitMCNull:
 950   case Backend_EmitObj:
 951     NeedCodeGen = true;
 952     CodeGenPasses.add(
 953         createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
 954     if (!AddEmitPasses(CodeGenPasses, Action, *OS))
 955       // FIXME: Should we handle this error differently?
 956       return;
 957     break;
 958   }
 959
 960   // Before executing passes, print the final values of the LLVM options.
 961   cl::PrintOptionValues();
 962
 963   // Now that we have all of the passes ready, run them.
 964   {
 965     PrettyStackTraceString CrashInfo("Optimizer");
 966     MPM.run(*TheModule, MAM);
 967   }
 968
 969   // Now if needed, run the legacy PM for codegen.
 970   if (NeedCodeGen) {
 971     PrettyStackTraceString CrashInfo("Code generation");
 972     CodeGenPasses.run(*TheModule);
 973   }
 974 }
 975
 976 Expected<BitcodeModule> clang::FindThinLTOModule(MemoryBufferRef MBRef) {
 977   Expected<std::vector<BitcodeModule>> BMsOrErr = getBitcodeModuleList(MBRef);
 978   if (!BMsOrErr)
 979     return BMsOrErr.takeError();
 980
 981   // The bitcode file may contain multiple modules, we want the one that is
 982   // marked as being the ThinLTO module.
 983   for (BitcodeModule &BM : *BMsOrErr) {
 984     Expected<BitcodeLTOInfo> LTOInfo = BM.getLTOInfo();
 985     if (LTOInfo && LTOInfo->IsThinLTO)
 986       return BM;
 987   }
 988
 989   return make_error<StringError>("Could not find module summary",
 990                                  inconvertibleErrorCode());
 991 }
 992
 993 static void runThinLTOBackend(ModuleSummaryIndex *CombinedIndex, Module *M,
 994                               const HeaderSearchOptions &HeaderOpts,
 995                               const CodeGenOptions &CGOpts,
 996                               const clang::TargetOptions &TOpts,
 997                               const LangOptions &LOpts,
 998                               std::unique_ptr<raw_pwrite_stream> OS,
 999                               std::string SampleProfile,
1000                               BackendAction Action) {
1001   StringMap<DenseMap<GlobalValue::GUID, GlobalValueSummary *>>
1002       ModuleToDefinedGVSummaries;
1003   CombinedIndex->collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries);
1004
1005   setCommandLineOpts(CGOpts);
1006
1007   // We can simply import the values mentioned in the combined index, since
1008   // we should only invoke this using the individual indexes written out
1009   // via a WriteIndexesThinBackend.
1010   FunctionImporter::ImportMapTy ImportList;
1011   for (auto &GlobalList : *CombinedIndex) {
1012     // Ignore entries for undefined references.
1013     if (GlobalList.second.SummaryList.empty())
1014       continue;
1015
1016     auto GUID = GlobalList.first;
1017     assert(GlobalList.second.SummaryList.size() == 1 &&
1018            "Expected individual combined index to have one summary per GUID");
1019     auto &Summary = GlobalList.second.SummaryList[0];
1020     // Skip the summaries for the importing module. These are included to
1021     // e.g. record required linkage changes.
1022     if (Summary->modulePath() == M->getModuleIdentifier())
1023       continue;
1024     // Doesn't matter what value we plug in to the map, just needs an entry
1025     // to provoke importing by thinBackend.
1026     ImportList[Summary->modulePath()][GUID] = 1;
1027   }
1028
1029   std::vector<std::unique_ptr<llvm::MemoryBuffer>> OwnedImports;
1030   MapVector<llvm::StringRef, llvm::BitcodeModule> ModuleMap;
1031
1032   for (auto &I : ImportList) {
1033     ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> MBOrErr =
1034         llvm::MemoryBuffer::getFile(I.first());
1035     if (!MBOrErr) {
1036       errs() << "Error loading imported file '" << I.first()
1037              << "': " << MBOrErr.getError().message() << "\n";
1038       return;
1039     }
1040
1041     Expected<BitcodeModule> BMOrErr = FindThinLTOModule(**MBOrErr);
1042     if (!BMOrErr) {
1043       handleAllErrors(BMOrErr.takeError(), [&](ErrorInfoBase &EIB) {
1044         errs() << "Error loading imported file '" << I.first()
1045                << "': " << EIB.message() << '\n';
1046       });
1047       return;
1048     }
1049     ModuleMap.insert({I.first(), *BMOrErr});
1050
1051     OwnedImports.push_back(std::move(*MBOrErr));
1052   }
1053   auto AddStream = [&](size_t Task) {
1054     return llvm::make_unique<lto::NativeObjectStream>(std::move(OS));
1055   };
1056   lto::Config Conf;
1057   Conf.CPU = TOpts.CPU;
1058   Conf.CodeModel = getCodeModel(CGOpts);
1059   Conf.MAttrs = TOpts.Features;
1060   Conf.RelocModel = getRelocModel(CGOpts);
1061   Conf.CGOptLevel = getCGOptLevel(CGOpts);
1062   initTargetOptions(Conf.Options, CGOpts, TOpts, LOpts, HeaderOpts);
1063   Conf.SampleProfile = std::move(SampleProfile);
1064   Conf.UseNewPM = CGOpts.ExperimentalNewPassManager;
1065   switch (Action) {
1066   case Backend_EmitNothing:
1067     Conf.PreCodeGenModuleHook = [](size_t Task, const Module &Mod) {
1068       return false;
1069     };
1070     break;
1071   case Backend_EmitLL:
1072     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1073       M->print(*OS, nullptr, CGOpts.EmitLLVMUseLists);
1074       return false;
1075     };
1076     break;
1077   case Backend_EmitBC:
1078     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1079       WriteBitcodeToFile(M, *OS, CGOpts.EmitLLVMUseLists);
1080       return false;
1081     };
1082     break;
1083   default:
1084     Conf.CGFileType = getCodeGenFileType(Action);
1085     break;
1086   }
1087   if (Error E = thinBackend(
1088           Conf, 0, AddStream, *M, *CombinedIndex, ImportList,
1089           ModuleToDefinedGVSummaries[M->getModuleIdentifier()], ModuleMap)) {
1090     handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1091       errs() << "Error running ThinLTO backend: " << EIB.message() << '\n';
1092     });
1093   }
1094 }
1095
1096 void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
1097                               const HeaderSearchOptions &HeaderOpts,
1098                               const CodeGenOptions &CGOpts,
1099                               const clang::TargetOptions &TOpts,
1100                               const LangOptions &LOpts,
1101                               const llvm::DataLayout &TDesc, Module *M,
1102                               BackendAction Action,
1103                               std::unique_ptr<raw_pwrite_stream> OS) {
1104   if (!CGOpts.ThinLTOIndexFile.empty()) {
1105     // If we are performing a ThinLTO importing compile, load the function index
1106     // into memory and pass it into runThinLTOBackend, which will run the
1107     // function importer and invoke LTO passes.
1108     Expected<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
1109         llvm::getModuleSummaryIndexForFile(CGOpts.ThinLTOIndexFile,
1110                                            /*IgnoreEmptyThinLTOIndexFile*/true);
1111     if (!IndexOrErr) {
1112       logAllUnhandledErrors(IndexOrErr.takeError(), errs(),
1113                             "Error loading index file '" +
1114                             CGOpts.ThinLTOIndexFile + "': ");
1115       return;
1116     }
1117     std::unique_ptr<ModuleSummaryIndex> CombinedIndex = std::move(*IndexOrErr);
1118     // A null CombinedIndex means we should skip ThinLTO compilation
1119     // (LLVM will optionally ignore empty index files, returning null instead
1120     // of an error).
1121     bool DoThinLTOBackend = CombinedIndex != nullptr;
1122     if (DoThinLTOBackend) {
1123       runThinLTOBackend(CombinedIndex.get(), M, HeaderOpts, CGOpts, TOpts,
1124                         LOpts, std::move(OS), CGOpts.SampleProfileFile, Action);
1125       return;
1126     }
1127   }
1128
1129   EmitAssemblyHelper AsmHelper(Diags, HeaderOpts, CGOpts, TOpts, LOpts, M);
1130
1131   if (CGOpts.ExperimentalNewPassManager)
1132     AsmHelper.EmitAssemblyWithNewPassManager(Action, std::move(OS));
1133   else
1134     AsmHelper.EmitAssembly(Action, std::move(OS));
1135
1136   // Verify clang's TargetInfo DataLayout against the LLVM TargetMachine's
1137   // DataLayout.
1138   if (AsmHelper.TM) {
1139     std::string DLDesc = M->getDataLayout().getStringRepresentation();
1140     if (DLDesc != TDesc.getStringRepresentation()) {
1141       unsigned DiagID = Diags.getCustomDiagID(
1142           DiagnosticsEngine::Error, "backend data layout '%0' does not match "
1143                                     "expected target description '%1'");
1144       Diags.Report(DiagID) << DLDesc << TDesc.getStringRepresentation();
1145     }
1146   }
1147 }
1148
1149 static const char* getSectionNameForBitcode(const Triple &T) {
1150   switch (T.getObjectFormat()) {
1151   case Triple::MachO:
1152     return "__LLVM,__bitcode";
1153   case Triple::COFF:
1154   case Triple::ELF:
1155   case Triple::Wasm:
1156   case Triple::UnknownObjectFormat:
1157     return ".llvmbc";
1158   }
1159   llvm_unreachable("Unimplemented ObjectFormatType");
1160 }
1161
1162 static const char* getSectionNameForCommandline(const Triple &T) {
1163   switch (T.getObjectFormat()) {
1164   case Triple::MachO:
1165     return "__LLVM,__cmdline";
1166   case Triple::COFF:
1167   case Triple::ELF:
1168   case Triple::Wasm:
1169   case Triple::UnknownObjectFormat:
1170     return ".llvmcmd";
1171   }
1172   llvm_unreachable("Unimplemented ObjectFormatType");
1173 }
1174
1175 // With -fembed-bitcode, save a copy of the llvm IR as data in the
1176 // __LLVM,__bitcode section.
1177 void clang::EmbedBitcode(llvm::Module *M, const CodeGenOptions &CGOpts,
1178                          llvm::MemoryBufferRef Buf) {
1179   if (CGOpts.getEmbedBitcode() == CodeGenOptions::Embed_Off)
1180     return;
1181
1182   // Save llvm.compiler.used and remote it.
1183   SmallVector<Constant*, 2> UsedArray;
1184   SmallSet<GlobalValue*, 4> UsedGlobals;
1185   Type *UsedElementType = Type::getInt8Ty(M->getContext())->getPointerTo(0);
1186   GlobalVariable *Used = collectUsedGlobalVariables(*M, UsedGlobals, true);
1187   for (auto *GV : UsedGlobals) {
1188     if (GV->getName() != "llvm.embedded.module" &&
1189         GV->getName() != "llvm.cmdline")
1190       UsedArray.push_back(
1191           ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
1192   }
1193   if (Used)
1194     Used->eraseFromParent();
1195
1196   // Embed the bitcode for the llvm module.
1197   std::string Data;
1198   ArrayRef<uint8_t> ModuleData;
1199   Triple T(M->getTargetTriple());
1200   // Create a constant that contains the bitcode.
1201   // In case of embedding a marker, ignore the input Buf and use the empty
1202   // ArrayRef. It is also legal to create a bitcode marker even Buf is empty.
1203   if (CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Marker) {
1204     if (!isBitcode((const unsigned char *)Buf.getBufferStart(),
1205                    (const unsigned char *)Buf.getBufferEnd())) {
1206       // If the input is LLVM Assembly, bitcode is produced by serializing
1207       // the module. Use-lists order need to be perserved in this case.
1208       llvm::raw_string_ostream OS(Data);
1209       llvm::WriteBitcodeToFile(M, OS, /* ShouldPreserveUseListOrder */ true);
1210       ModuleData =
1211           ArrayRef<uint8_t>((const uint8_t *)OS.str().data(), OS.str().size());
1212     } else
1213       // If the input is LLVM bitcode, write the input byte stream directly.
1214       ModuleData = ArrayRef<uint8_t>((const uint8_t *)Buf.getBufferStart(),
1215                                      Buf.getBufferSize());
1216   }
1217   llvm::Constant *ModuleConstant =
1218       llvm::ConstantDataArray::get(M->getContext(), ModuleData);
1219   llvm::GlobalVariable *GV = new llvm::GlobalVariable(
1220       *M, ModuleConstant->getType(), true, llvm::GlobalValue::PrivateLinkage,
1221       ModuleConstant);
1222   GV->setSection(getSectionNameForBitcode(T));
1223   UsedArray.push_back(
1224       ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
1225   if (llvm::GlobalVariable *Old =
1226           M->getGlobalVariable("llvm.embedded.module", true)) {
1227     assert(Old->hasOneUse() &&
1228            "llvm.embedded.module can only be used once in llvm.compiler.used");
1229     GV->takeName(Old);
1230     Old->eraseFromParent();
1231   } else {
1232     GV->setName("llvm.embedded.module");
1233   }
1234
1235   // Skip if only bitcode needs to be embedded.
1236   if (CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Bitcode) {
1237     // Embed command-line options.
1238     ArrayRef<uint8_t> CmdData(const_cast<uint8_t *>(CGOpts.CmdArgs.data()),
1239                               CGOpts.CmdArgs.size());
1240     llvm::Constant *CmdConstant =
1241       llvm::ConstantDataArray::get(M->getContext(), CmdData);
1242     GV = new llvm::GlobalVariable(*M, CmdConstant->getType(), true,
1243                                   llvm::GlobalValue::PrivateLinkage,
1244                                   CmdConstant);
1245     GV->setSection(getSectionNameForCommandline(T));
1246     UsedArray.push_back(
1247         ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
1248     if (llvm::GlobalVariable *Old =
1249             M->getGlobalVariable("llvm.cmdline", true)) {
1250       assert(Old->hasOneUse() &&
1251              "llvm.cmdline can only be used once in llvm.compiler.used");
1252       GV->takeName(Old);
1253       Old->eraseFromParent();
1254     } else {
1255       GV->setName("llvm.cmdline");
1256     }
1257   }
1258
1259   if (UsedArray.empty())
1260     return;
1261
1262   // Recreate llvm.compiler.used.
1263   ArrayType *ATy = ArrayType::get(UsedElementType, UsedArray.size());
1264   auto *NewUsed = new GlobalVariable(
1265       *M, ATy, false, llvm::GlobalValue::AppendingLinkage,
1266       llvm::ConstantArray::get(ATy, UsedArray), "llvm.compiler.used");
1267   NewUsed->setSection("llvm.metadata");
1268 }