clang/lib/CodeGen/BackendUtil.cpp

   1 //===--- BackendUtil.cpp - LLVM Backend Utilities -------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "clang/CodeGen/BackendUtil.h"
  10 #include "clang/Basic/CodeGenOptions.h"
  11 #include "clang/Basic/Diagnostic.h"
  12 #include "clang/Basic/LangOptions.h"
  13 #include "clang/Basic/TargetOptions.h"
  14 #include "clang/Frontend/FrontendDiagnostic.h"
  15 #include "clang/Frontend/Utils.h"
  16 #include "clang/Lex/HeaderSearchOptions.h"
  17 #include "llvm/ADT/SmallSet.h"
  18 #include "llvm/ADT/StringExtras.h"
  19 #include "llvm/ADT/StringSwitch.h"
  20 #include "llvm/Analysis/AliasAnalysis.h"
  21 #include "llvm/Analysis/GlobalsModRef.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/CodeGen/TargetSubtargetInfo.h"
  30 #include "llvm/IR/DataLayout.h"
  31 #include "llvm/IR/DebugInfo.h"
  32 #include "llvm/IR/LegacyPassManager.h"
  33 #include "llvm/IR/Module.h"
  34 #include "llvm/IR/ModuleSummaryIndex.h"
  35 #include "llvm/IR/PassManager.h"
  36 #include "llvm/IR/Verifier.h"
  37 #include "llvm/IRPrinter/IRPrintingPasses.h"
  38 #include "llvm/LTO/LTOBackend.h"
  39 #include "llvm/MC/MCAsmInfo.h"
  40 #include "llvm/MC/SubtargetFeature.h"
  41 #include "llvm/MC/TargetRegistry.h"
  42 #include "llvm/Object/OffloadBinary.h"
  43 #include "llvm/Passes/PassBuilder.h"
  44 #include "llvm/Passes/PassPlugin.h"
  45 #include "llvm/Passes/StandardInstrumentations.h"
  46 #include "llvm/Support/BuryPointer.h"
  47 #include "llvm/Support/CommandLine.h"
  48 #include "llvm/Support/MemoryBuffer.h"
  49 #include "llvm/Support/PrettyStackTrace.h"
  50 #include "llvm/Support/TimeProfiler.h"
  51 #include "llvm/Support/Timer.h"
  52 #include "llvm/Support/ToolOutputFile.h"
  53 #include "llvm/Support/VirtualFileSystem.h"
  54 #include "llvm/Support/raw_ostream.h"
  55 #include "llvm/Target/TargetMachine.h"
  56 #include "llvm/Target/TargetOptions.h"
  57 #include "llvm/TargetParser/Triple.h"
  58 #include "llvm/Transforms/IPO/LowerTypeTests.h"
  59 #include "llvm/Transforms/IPO/ThinLTOBitcodeWriter.h"
  60 #include "llvm/Transforms/InstCombine/InstCombine.h"
  61 #include "llvm/Transforms/Instrumentation.h"
  62 #include "llvm/Transforms/Instrumentation/AddressSanitizer.h"
  63 #include "llvm/Transforms/Instrumentation/AddressSanitizerOptions.h"
  64 #include "llvm/Transforms/Instrumentation/BoundsChecking.h"
  65 #include "llvm/Transforms/Instrumentation/DataFlowSanitizer.h"
  66 #include "llvm/Transforms/Instrumentation/GCOVProfiler.h"
  67 #include "llvm/Transforms/Instrumentation/HWAddressSanitizer.h"
  68 #include "llvm/Transforms/Instrumentation/InstrProfiling.h"
  69 #include "llvm/Transforms/Instrumentation/KCFI.h"
  70 #include "llvm/Transforms/Instrumentation/MemProfiler.h"
  71 #include "llvm/Transforms/Instrumentation/MemorySanitizer.h"
  72 #include "llvm/Transforms/Instrumentation/SanitizerBinaryMetadata.h"
  73 #include "llvm/Transforms/Instrumentation/SanitizerCoverage.h"
  74 #include "llvm/Transforms/Instrumentation/ThreadSanitizer.h"
  75 #include "llvm/Transforms/ObjCARC.h"
  76 #include "llvm/Transforms/Scalar/EarlyCSE.h"
  77 #include "llvm/Transforms/Scalar/GVN.h"
  78 #include "llvm/Transforms/Scalar/JumpThreading.h"
  79 #include "llvm/Transforms/Utils/Debugify.h"
  80 #include "llvm/Transforms/Utils/EntryExitInstrumenter.h"
  81 #include "llvm/Transforms/Utils/ModuleUtils.h"
  82 #include <memory>
  83 #include <optional>
  84 using namespace clang;
  85 using namespace llvm;
  86
  87 #define HANDLE_EXTENSION(Ext)                                                  \
  88   llvm::PassPluginLibraryInfo get##Ext##PluginInfo();
  89 #include "llvm/Support/Extension.def"
  90
  91 namespace llvm {
  92 extern cl::opt<bool> DebugInfoCorrelate;
  93
  94 // Experiment to move sanitizers earlier.
  95 static cl::opt<bool> ClSanitizeOnOptimizerEarlyEP(
  96     "sanitizer-early-opt-ep", cl::Optional,
  97     cl::desc("Insert sanitizers on OptimizerEarlyEP."), cl::init(false));
  98 }
  99
 100 namespace {
 101
 102 // Default filename used for profile generation.
 103 std::string getDefaultProfileGenName() {
 104   return DebugInfoCorrelate ? "default_%p.proflite" : "default_%m.profraw";
 105 }
 106
 107 class EmitAssemblyHelper {
 108   DiagnosticsEngine &Diags;
 109   const HeaderSearchOptions &HSOpts;
 110   const CodeGenOptions &CodeGenOpts;
 111   const clang::TargetOptions &TargetOpts;
 112   const LangOptions &LangOpts;
 113   Module *TheModule;
 114   IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS;
 115
 116   Timer CodeGenerationTime;
 117
 118   std::unique_ptr<raw_pwrite_stream> OS;
 119
 120   Triple TargetTriple;
 121
 122   TargetIRAnalysis getTargetIRAnalysis() const {
 123     if (TM)
 124       return TM->getTargetIRAnalysis();
 125
 126     return TargetIRAnalysis();
 127   }
 128
 129   /// Generates the TargetMachine.
 130   /// Leaves TM unchanged if it is unable to create the target machine.
 131   /// Some of our clang tests specify triples which are not built
 132   /// into clang. This is okay because these tests check the generated
 133   /// IR, and they require DataLayout which depends on the triple.
 134   /// In this case, we allow this method to fail and not report an error.
 135   /// When MustCreateTM is used, we print an error if we are unable to load
 136   /// the requested target.
 137   void CreateTargetMachine(bool MustCreateTM);
 138
 139   /// Add passes necessary to emit assembly or LLVM IR.
 140   ///
 141   /// \return True on success.
 142   bool AddEmitPasses(legacy::PassManager &CodeGenPasses, BackendAction Action,
 143                      raw_pwrite_stream &OS, raw_pwrite_stream *DwoOS);
 144
 145   std::unique_ptr<llvm::ToolOutputFile> openOutputFile(StringRef Path) {
 146     std::error_code EC;
 147     auto F = std::make_unique<llvm::ToolOutputFile>(Path, EC,
 148                                                      llvm::sys::fs::OF_None);
 149     if (EC) {
 150       Diags.Report(diag::err_fe_unable_to_open_output) << Path << EC.message();
 151       F.reset();
 152     }
 153     return F;
 154   }
 155
 156   void
 157   RunOptimizationPipeline(BackendAction Action,
 158                           std::unique_ptr<raw_pwrite_stream> &OS,
 159                           std::unique_ptr<llvm::ToolOutputFile> &ThinLinkOS);
 160   void RunCodegenPipeline(BackendAction Action,
 161                           std::unique_ptr<raw_pwrite_stream> &OS,
 162                           std::unique_ptr<llvm::ToolOutputFile> &DwoOS);
 163
 164   /// Check whether we should emit a module summary for regular LTO.
 165   /// The module summary should be emitted by default for regular LTO
 166   /// except for ld64 targets.
 167   ///
 168   /// \return True if the module summary should be emitted.
 169   bool shouldEmitRegularLTOSummary() const {
 170     return CodeGenOpts.PrepareForLTO && !CodeGenOpts.DisableLLVMPasses &&
 171            TargetTriple.getVendor() != llvm::Triple::Apple;
 172   }
 173
 174 public:
 175   EmitAssemblyHelper(DiagnosticsEngine &_Diags,
 176                      const HeaderSearchOptions &HeaderSearchOpts,
 177                      const CodeGenOptions &CGOpts,
 178                      const clang::TargetOptions &TOpts,
 179                      const LangOptions &LOpts, Module *M,
 180                      IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS)
 181       : Diags(_Diags), HSOpts(HeaderSearchOpts), CodeGenOpts(CGOpts),
 182         TargetOpts(TOpts), LangOpts(LOpts), TheModule(M), VFS(std::move(VFS)),
 183         CodeGenerationTime("codegen", "Code Generation Time"),
 184         TargetTriple(TheModule->getTargetTriple()) {}
 185
 186   ~EmitAssemblyHelper() {
 187     if (CodeGenOpts.DisableFree)
 188       BuryPointer(std::move(TM));
 189   }
 190
 191   std::unique_ptr<TargetMachine> TM;
 192
 193   // Emit output using the new pass manager for the optimization pipeline.
 194   void EmitAssembly(BackendAction Action,
 195                     std::unique_ptr<raw_pwrite_stream> OS);
 196 };
 197 }
 198
 199 static SanitizerCoverageOptions
 200 getSancovOptsFromCGOpts(const CodeGenOptions &CGOpts) {
 201   SanitizerCoverageOptions Opts;
 202   Opts.CoverageType =
 203       static_cast<SanitizerCoverageOptions::Type>(CGOpts.SanitizeCoverageType);
 204   Opts.IndirectCalls = CGOpts.SanitizeCoverageIndirectCalls;
 205   Opts.TraceBB = CGOpts.SanitizeCoverageTraceBB;
 206   Opts.TraceCmp = CGOpts.SanitizeCoverageTraceCmp;
 207   Opts.TraceDiv = CGOpts.SanitizeCoverageTraceDiv;
 208   Opts.TraceGep = CGOpts.SanitizeCoverageTraceGep;
 209   Opts.Use8bitCounters = CGOpts.SanitizeCoverage8bitCounters;
 210   Opts.TracePC = CGOpts.SanitizeCoverageTracePC;
 211   Opts.TracePCGuard = CGOpts.SanitizeCoverageTracePCGuard;
 212   Opts.NoPrune = CGOpts.SanitizeCoverageNoPrune;
 213   Opts.Inline8bitCounters = CGOpts.SanitizeCoverageInline8bitCounters;
 214   Opts.InlineBoolFlag = CGOpts.SanitizeCoverageInlineBoolFlag;
 215   Opts.PCTable = CGOpts.SanitizeCoveragePCTable;
 216   Opts.StackDepth = CGOpts.SanitizeCoverageStackDepth;
 217   Opts.TraceLoads = CGOpts.SanitizeCoverageTraceLoads;
 218   Opts.TraceStores = CGOpts.SanitizeCoverageTraceStores;
 219   Opts.CollectControlFlow = CGOpts.SanitizeCoverageControlFlow;
 220   return Opts;
 221 }
 222
 223 static SanitizerBinaryMetadataOptions
 224 getSanitizerBinaryMetadataOptions(const CodeGenOptions &CGOpts) {
 225   SanitizerBinaryMetadataOptions Opts;
 226   Opts.Covered = CGOpts.SanitizeBinaryMetadataCovered;
 227   Opts.Atomics = CGOpts.SanitizeBinaryMetadataAtomics;
 228   Opts.UAR = CGOpts.SanitizeBinaryMetadataUAR;
 229   return Opts;
 230 }
 231
 232 // Check if ASan should use GC-friendly instrumentation for globals.
 233 // First of all, there is no point if -fdata-sections is off (expect for MachO,
 234 // where this is not a factor). Also, on ELF this feature requires an assembler
 235 // extension that only works with -integrated-as at the moment.
 236 static bool asanUseGlobalsGC(const Triple &T, const CodeGenOptions &CGOpts) {
 237   if (!CGOpts.SanitizeAddressGlobalsDeadStripping)
 238     return false;
 239   switch (T.getObjectFormat()) {
 240   case Triple::MachO:
 241   case Triple::COFF:
 242     return true;
 243   case Triple::ELF:
 244     return !CGOpts.DisableIntegratedAS;
 245   case Triple::GOFF:
 246     llvm::report_fatal_error("ASan not implemented for GOFF");
 247   case Triple::XCOFF:
 248     llvm::report_fatal_error("ASan not implemented for XCOFF.");
 249   case Triple::Wasm:
 250   case Triple::DXContainer:
 251   case Triple::SPIRV:
 252   case Triple::UnknownObjectFormat:
 253     break;
 254   }
 255   return false;
 256 }
 257
 258 static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
 259                                          const CodeGenOptions &CodeGenOpts) {
 260   TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple);
 261
 262   switch (CodeGenOpts.getVecLib()) {
 263   case CodeGenOptions::Accelerate:
 264     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::Accelerate,
 265                                              TargetTriple);
 266     break;
 267   case CodeGenOptions::LIBMVEC:
 268     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::LIBMVEC_X86,
 269                                              TargetTriple);
 270     break;
 271   case CodeGenOptions::MASSV:
 272     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::MASSV,
 273                                              TargetTriple);
 274     break;
 275   case CodeGenOptions::SVML:
 276     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::SVML,
 277                                              TargetTriple);
 278     break;
 279   case CodeGenOptions::SLEEF:
 280     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::SLEEFGNUABI,
 281                                              TargetTriple);
 282     break;
 283   case CodeGenOptions::Darwin_libsystem_m:
 284     TLII->addVectorizableFunctionsFromVecLib(
 285         TargetLibraryInfoImpl::DarwinLibSystemM, TargetTriple);
 286     break;
 287   default:
 288     break;
 289   }
 290   return TLII;
 291 }
 292
 293 static std::optional<llvm::CodeModel::Model>
 294 getCodeModel(const CodeGenOptions &CodeGenOpts) {
 295   unsigned CodeModel = llvm::StringSwitch<unsigned>(CodeGenOpts.CodeModel)
 296                            .Case("tiny", llvm::CodeModel::Tiny)
 297                            .Case("small", llvm::CodeModel::Small)
 298                            .Case("kernel", llvm::CodeModel::Kernel)
 299                            .Case("medium", llvm::CodeModel::Medium)
 300                            .Case("large", llvm::CodeModel::Large)
 301                            .Case("default", ~1u)
 302                            .Default(~0u);
 303   assert(CodeModel != ~0u && "invalid code model!");
 304   if (CodeModel == ~1u)
 305     return std::nullopt;
 306   return static_cast<llvm::CodeModel::Model>(CodeModel);
 307 }
 308
 309 static CodeGenFileType getCodeGenFileType(BackendAction Action) {
 310   if (Action == Backend_EmitObj)
 311     return CGFT_ObjectFile;
 312   else if (Action == Backend_EmitMCNull)
 313     return CGFT_Null;
 314   else {
 315     assert(Action == Backend_EmitAssembly && "Invalid action!");
 316     return CGFT_AssemblyFile;
 317   }
 318 }
 319
 320 static bool actionRequiresCodeGen(BackendAction Action) {
 321   return Action != Backend_EmitNothing && Action != Backend_EmitBC &&
 322          Action != Backend_EmitLL;
 323 }
 324
 325 static bool initTargetOptions(DiagnosticsEngine &Diags,
 326                               llvm::TargetOptions &Options,
 327                               const CodeGenOptions &CodeGenOpts,
 328                               const clang::TargetOptions &TargetOpts,
 329                               const LangOptions &LangOpts,
 330                               const HeaderSearchOptions &HSOpts) {
 331   switch (LangOpts.getThreadModel()) {
 332   case LangOptions::ThreadModelKind::POSIX:
 333     Options.ThreadModel = llvm::ThreadModel::POSIX;
 334     break;
 335   case LangOptions::ThreadModelKind::Single:
 336     Options.ThreadModel = llvm::ThreadModel::Single;
 337     break;
 338   }
 339
 340   // Set float ABI type.
 341   assert((CodeGenOpts.FloatABI == "soft" || CodeGenOpts.FloatABI == "softfp" ||
 342           CodeGenOpts.FloatABI == "hard" || CodeGenOpts.FloatABI.empty()) &&
 343          "Invalid Floating Point ABI!");
 344   Options.FloatABIType =
 345       llvm::StringSwitch<llvm::FloatABI::ABIType>(CodeGenOpts.FloatABI)
 346           .Case("soft", llvm::FloatABI::Soft)
 347           .Case("softfp", llvm::FloatABI::Soft)
 348           .Case("hard", llvm::FloatABI::Hard)
 349           .Default(llvm::FloatABI::Default);
 350
 351   // Set FP fusion mode.
 352   switch (LangOpts.getDefaultFPContractMode()) {
 353   case LangOptions::FPM_Off:
 354     // Preserve any contraction performed by the front-end.  (Strict performs
 355     // splitting of the muladd intrinsic in the backend.)
 356     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
 357     break;
 358   case LangOptions::FPM_On:
 359   case LangOptions::FPM_FastHonorPragmas:
 360     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
 361     break;
 362   case LangOptions::FPM_Fast:
 363     Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
 364     break;
 365   }
 366
 367   Options.BinutilsVersion =
 368       llvm::TargetMachine::parseBinutilsVersion(CodeGenOpts.BinutilsVersion);
 369   Options.UseInitArray = CodeGenOpts.UseInitArray;
 370   Options.LowerGlobalDtorsViaCxaAtExit =
 371       CodeGenOpts.RegisterGlobalDtorsWithAtExit;
 372   Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
 373   Options.CompressDebugSections = CodeGenOpts.getCompressDebugSections();
 374   Options.RelaxELFRelocations = CodeGenOpts.RelaxELFRelocations;
 375
 376   // Set EABI version.
 377   Options.EABIVersion = TargetOpts.EABIVersion;
 378
 379   if (LangOpts.hasSjLjExceptions())
 380     Options.ExceptionModel = llvm::ExceptionHandling::SjLj;
 381   if (LangOpts.hasSEHExceptions())
 382     Options.ExceptionModel = llvm::ExceptionHandling::WinEH;
 383   if (LangOpts.hasDWARFExceptions())
 384     Options.ExceptionModel = llvm::ExceptionHandling::DwarfCFI;
 385   if (LangOpts.hasWasmExceptions())
 386     Options.ExceptionModel = llvm::ExceptionHandling::Wasm;
 387
 388   Options.NoInfsFPMath = LangOpts.NoHonorInfs;
 389   Options.NoNaNsFPMath = LangOpts.NoHonorNaNs;
 390   Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
 391   Options.UnsafeFPMath = LangOpts.AllowFPReassoc && LangOpts.AllowRecip &&
 392                          LangOpts.NoSignedZero && LangOpts.ApproxFunc &&
 393                          (LangOpts.getDefaultFPContractMode() ==
 394                               LangOptions::FPModeKind::FPM_Fast ||
 395                           LangOpts.getDefaultFPContractMode() ==
 396                               LangOptions::FPModeKind::FPM_FastHonorPragmas);
 397   Options.ApproxFuncFPMath = LangOpts.ApproxFunc;
 398
 399   Options.BBSections =
 400       llvm::StringSwitch<llvm::BasicBlockSection>(CodeGenOpts.BBSections)
 401           .Case("all", llvm::BasicBlockSection::All)
 402           .Case("labels", llvm::BasicBlockSection::Labels)
 403           .StartsWith("list=", llvm::BasicBlockSection::List)
 404           .Case("none", llvm::BasicBlockSection::None)
 405           .Default(llvm::BasicBlockSection::None);
 406
 407   if (Options.BBSections == llvm::BasicBlockSection::List) {
 408     ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
 409         MemoryBuffer::getFile(CodeGenOpts.BBSections.substr(5));
 410     if (!MBOrErr) {
 411       Diags.Report(diag::err_fe_unable_to_load_basic_block_sections_file)
 412           << MBOrErr.getError().message();
 413       return false;
 414     }
 415     Options.BBSectionsFuncListBuf = std::move(*MBOrErr);
 416   }
 417
 418   Options.EnableMachineFunctionSplitter = CodeGenOpts.SplitMachineFunctions;
 419   Options.FunctionSections = CodeGenOpts.FunctionSections;
 420   Options.DataSections = CodeGenOpts.DataSections;
 421   Options.IgnoreXCOFFVisibility = LangOpts.IgnoreXCOFFVisibility;
 422   Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
 423   Options.UniqueBasicBlockSectionNames =
 424       CodeGenOpts.UniqueBasicBlockSectionNames;
 425   Options.TLSSize = CodeGenOpts.TLSSize;
 426   Options.EmulatedTLS = CodeGenOpts.EmulatedTLS;
 427   Options.ExplicitEmulatedTLS = true;
 428   Options.DebuggerTuning = CodeGenOpts.getDebuggerTuning();
 429   Options.EmitStackSizeSection = CodeGenOpts.StackSizeSection;
 430   Options.StackUsageOutput = CodeGenOpts.StackUsageOutput;
 431   Options.EmitAddrsig = CodeGenOpts.Addrsig;
 432   Options.ForceDwarfFrameSection = CodeGenOpts.ForceDwarfFrameSection;
 433   Options.EmitCallSiteInfo = CodeGenOpts.EmitCallSiteInfo;
 434   Options.EnableAIXExtendedAltivecABI = CodeGenOpts.EnableAIXExtendedAltivecABI;
 435   Options.XRayOmitFunctionIndex = CodeGenOpts.XRayOmitFunctionIndex;
 436   Options.LoopAlignment = CodeGenOpts.LoopAlignment;
 437   Options.DebugStrictDwarf = CodeGenOpts.DebugStrictDwarf;
 438   Options.ObjectFilenameForDebug = CodeGenOpts.ObjectFilenameForDebug;
 439   Options.Hotpatch = CodeGenOpts.HotPatch;
 440   Options.JMCInstrument = CodeGenOpts.JMCInstrument;
 441
 442   switch (CodeGenOpts.getSwiftAsyncFramePointer()) {
 443   case CodeGenOptions::SwiftAsyncFramePointerKind::Auto:
 444     Options.SwiftAsyncFramePointer =
 445         SwiftAsyncFramePointerMode::DeploymentBased;
 446     break;
 447
 448   case CodeGenOptions::SwiftAsyncFramePointerKind::Always:
 449     Options.SwiftAsyncFramePointer = SwiftAsyncFramePointerMode::Always;
 450     break;
 451
 452   case CodeGenOptions::SwiftAsyncFramePointerKind::Never:
 453     Options.SwiftAsyncFramePointer = SwiftAsyncFramePointerMode::Never;
 454     break;
 455   }
 456
 457   Options.MCOptions.SplitDwarfFile = CodeGenOpts.SplitDwarfFile;
 458   Options.MCOptions.EmitDwarfUnwind = CodeGenOpts.getEmitDwarfUnwind();
 459   Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
 460   Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
 461   Options.MCOptions.MCUseDwarfDirectory =
 462       CodeGenOpts.NoDwarfDirectoryAsm
 463           ? llvm::MCTargetOptions::DisableDwarfDirectory
 464           : llvm::MCTargetOptions::EnableDwarfDirectory;
 465   Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
 466   Options.MCOptions.MCIncrementalLinkerCompatible =
 467       CodeGenOpts.IncrementalLinkerCompatible;
 468   Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
 469   Options.MCOptions.MCNoWarn = CodeGenOpts.NoWarn;
 470   Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
 471   Options.MCOptions.Dwarf64 = CodeGenOpts.Dwarf64;
 472   Options.MCOptions.PreserveAsmComments = CodeGenOpts.PreserveAsmComments;
 473   Options.MCOptions.ABIName = TargetOpts.ABI;
 474   for (const auto &Entry : HSOpts.UserEntries)
 475     if (!Entry.IsFramework &&
 476         (Entry.Group == frontend::IncludeDirGroup::Quoted ||
 477          Entry.Group == frontend::IncludeDirGroup::Angled ||
 478          Entry.Group == frontend::IncludeDirGroup::System))
 479       Options.MCOptions.IASSearchPaths.push_back(
 480           Entry.IgnoreSysRoot ? Entry.Path : HSOpts.Sysroot + Entry.Path);
 481   Options.MCOptions.Argv0 = CodeGenOpts.Argv0;
 482   Options.MCOptions.CommandLineArgs = CodeGenOpts.CommandLineArgs;
 483   Options.MCOptions.AsSecureLogFile = CodeGenOpts.AsSecureLogFile;
 484   Options.MisExpect = CodeGenOpts.MisExpect;
 485
 486   return true;
 487 }
 488
 489 static std::optional<GCOVOptions>
 490 getGCOVOptions(const CodeGenOptions &CodeGenOpts, const LangOptions &LangOpts) {
 491   if (!CodeGenOpts.EmitGcovArcs && !CodeGenOpts.EmitGcovNotes)
 492     return std::nullopt;
 493   // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
 494   // LLVM's -default-gcov-version flag is set to something invalid.
 495   GCOVOptions Options;
 496   Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
 497   Options.EmitData = CodeGenOpts.EmitGcovArcs;
 498   llvm::copy(CodeGenOpts.CoverageVersion, std::begin(Options.Version));
 499   Options.NoRedZone = CodeGenOpts.DisableRedZone;
 500   Options.Filter = CodeGenOpts.ProfileFilterFiles;
 501   Options.Exclude = CodeGenOpts.ProfileExcludeFiles;
 502   Options.Atomic = CodeGenOpts.AtomicProfileUpdate;
 503   return Options;
 504 }
 505
 506 static std::optional<InstrProfOptions>
 507 getInstrProfOptions(const CodeGenOptions &CodeGenOpts,
 508                     const LangOptions &LangOpts) {
 509   if (!CodeGenOpts.hasProfileClangInstr())
 510     return std::nullopt;
 511   InstrProfOptions Options;
 512   Options.NoRedZone = CodeGenOpts.DisableRedZone;
 513   Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
 514   Options.Atomic = CodeGenOpts.AtomicProfileUpdate;
 515   return Options;
 516 }
 517
 518 static void setCommandLineOpts(const CodeGenOptions &CodeGenOpts) {
 519   SmallVector<const char *, 16> BackendArgs;
 520   BackendArgs.push_back("clang"); // Fake program name.
 521   if (!CodeGenOpts.DebugPass.empty()) {
 522     BackendArgs.push_back("-debug-pass");
 523     BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
 524   }
 525   if (!CodeGenOpts.LimitFloatPrecision.empty()) {
 526     BackendArgs.push_back("-limit-float-precision");
 527     BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
 528   }
 529   // Check for the default "clang" invocation that won't set any cl::opt values.
 530   // Skip trying to parse the command line invocation to avoid the issues
 531   // described below.
 532   if (BackendArgs.size() == 1)
 533     return;
 534   BackendArgs.push_back(nullptr);
 535   // FIXME: The command line parser below is not thread-safe and shares a global
 536   // state, so this call might crash or overwrite the options of another Clang
 537   // instance in the same process.
 538   llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
 539                                     BackendArgs.data());
 540 }
 541
 542 void EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
 543   // Create the TargetMachine for generating code.
 544   std::string Error;
 545   std::string Triple = TheModule->getTargetTriple();
 546   const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
 547   if (!TheTarget) {
 548     if (MustCreateTM)
 549       Diags.Report(diag::err_fe_unable_to_create_target) << Error;
 550     return;
 551   }
 552
 553   std::optional<llvm::CodeModel::Model> CM = getCodeModel(CodeGenOpts);
 554   std::string FeaturesStr =
 555       llvm::join(TargetOpts.Features.begin(), TargetOpts.Features.end(), ",");
 556   llvm::Reloc::Model RM = CodeGenOpts.RelocationModel;
 557   std::optional<CodeGenOpt::Level> OptLevelOrNone =
 558       CodeGenOpt::getLevel(CodeGenOpts.OptimizationLevel);
 559   assert(OptLevelOrNone && "Invalid optimization level!");
 560   CodeGenOpt::Level OptLevel = *OptLevelOrNone;
 561
 562   llvm::TargetOptions Options;
 563   if (!initTargetOptions(Diags, Options, CodeGenOpts, TargetOpts, LangOpts,
 564                          HSOpts))
 565     return;
 566   TM.reset(TheTarget->createTargetMachine(Triple, TargetOpts.CPU, FeaturesStr,
 567                                           Options, RM, CM, OptLevel));
 568 }
 569
 570 bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
 571                                        BackendAction Action,
 572                                        raw_pwrite_stream &OS,
 573                                        raw_pwrite_stream *DwoOS) {
 574   // Add LibraryInfo.
 575   std::unique_ptr<TargetLibraryInfoImpl> TLII(
 576       createTLII(TargetTriple, CodeGenOpts));
 577   CodeGenPasses.add(new TargetLibraryInfoWrapperPass(*TLII));
 578
 579   // Normal mode, emit a .s or .o file by running the code generator. Note,
 580   // this also adds codegenerator level optimization passes.
 581   CodeGenFileType CGFT = getCodeGenFileType(Action);
 582
 583   // Add ObjC ARC final-cleanup optimizations. This is done as part of the
 584   // "codegen" passes so that it isn't run multiple times when there is
 585   // inlining happening.
 586   if (CodeGenOpts.OptimizationLevel > 0)
 587     CodeGenPasses.add(createObjCARCContractPass());
 588
 589   if (TM->addPassesToEmitFile(CodeGenPasses, OS, DwoOS, CGFT,
 590                               /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
 591     Diags.Report(diag::err_fe_unable_to_interface_with_target);
 592     return false;
 593   }
 594
 595   return true;
 596 }
 597
 598 static OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
 599   switch (Opts.OptimizationLevel) {
 600   default:
 601     llvm_unreachable("Invalid optimization level!");
 602
 603   case 0:
 604     return OptimizationLevel::O0;
 605
 606   case 1:
 607     return OptimizationLevel::O1;
 608
 609   case 2:
 610     switch (Opts.OptimizeSize) {
 611     default:
 612       llvm_unreachable("Invalid optimization level for size!");
 613
 614     case 0:
 615       return OptimizationLevel::O2;
 616
 617     case 1:
 618       return OptimizationLevel::Os;
 619
 620     case 2:
 621       return OptimizationLevel::Oz;
 622     }
 623
 624   case 3:
 625     return OptimizationLevel::O3;
 626   }
 627 }
 628
 629 static void addKCFIPass(const Triple &TargetTriple, const LangOptions &LangOpts,
 630                         PassBuilder &PB) {
 631   // If the back-end supports KCFI operand bundle lowering, skip KCFIPass.
 632   if (TargetTriple.getArch() == llvm::Triple::x86_64 ||
 633       TargetTriple.isAArch64(64))
 634     return;
 635
 636   // Ensure we lower KCFI operand bundles with -O0.
 637   PB.registerOptimizerLastEPCallback(
 638       [&](ModulePassManager &MPM, OptimizationLevel Level) {
 639         if (Level == OptimizationLevel::O0 &&
 640             LangOpts.Sanitize.has(SanitizerKind::KCFI))
 641           MPM.addPass(createModuleToFunctionPassAdaptor(KCFIPass()));
 642       });
 643
 644   // When optimizations are requested, run KCIFPass after InstCombine to
 645   // avoid unnecessary checks.
 646   PB.registerPeepholeEPCallback(
 647       [&](FunctionPassManager &FPM, OptimizationLevel Level) {
 648         if (Level != OptimizationLevel::O0 &&
 649             LangOpts.Sanitize.has(SanitizerKind::KCFI))
 650           FPM.addPass(KCFIPass());
 651       });
 652 }
 653
 654 static void addSanitizers(const Triple &TargetTriple,
 655                           const CodeGenOptions &CodeGenOpts,
 656                           const LangOptions &LangOpts, PassBuilder &PB) {
 657   auto SanitizersCallback = [&](ModulePassManager &MPM,
 658                                 OptimizationLevel Level) {
 659     if (CodeGenOpts.hasSanitizeCoverage()) {
 660       auto SancovOpts = getSancovOptsFromCGOpts(CodeGenOpts);
 661       MPM.addPass(SanitizerCoveragePass(
 662           SancovOpts, CodeGenOpts.SanitizeCoverageAllowlistFiles,
 663           CodeGenOpts.SanitizeCoverageIgnorelistFiles));
 664     }
 665
 666     if (CodeGenOpts.hasSanitizeBinaryMetadata()) {
 667       MPM.addPass(SanitizerBinaryMetadataPass(
 668           getSanitizerBinaryMetadataOptions(CodeGenOpts),
 669           CodeGenOpts.SanitizeMetadataIgnorelistFiles));
 670     }
 671
 672     auto MSanPass = [&](SanitizerMask Mask, bool CompileKernel) {
 673       if (LangOpts.Sanitize.has(Mask)) {
 674         int TrackOrigins = CodeGenOpts.SanitizeMemoryTrackOrigins;
 675         bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
 676
 677         MemorySanitizerOptions options(TrackOrigins, Recover, CompileKernel,
 678                                        CodeGenOpts.SanitizeMemoryParamRetval);
 679         MPM.addPass(MemorySanitizerPass(options));
 680         if (Level != OptimizationLevel::O0) {
 681           // MemorySanitizer inserts complex instrumentation that mostly follows
 682           // the logic of the original code, but operates on "shadow" values. It
 683           // can benefit from re-running some general purpose optimization
 684           // passes.
 685           MPM.addPass(RequireAnalysisPass<GlobalsAA, Module>());
 686           FunctionPassManager FPM;
 687           FPM.addPass(EarlyCSEPass(true /* Enable mem-ssa. */));
 688           FPM.addPass(InstCombinePass());
 689           FPM.addPass(JumpThreadingPass());
 690           FPM.addPass(GVNPass());
 691           FPM.addPass(InstCombinePass());
 692           MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
 693         }
 694       }
 695     };
 696     MSanPass(SanitizerKind::Memory, false);
 697     MSanPass(SanitizerKind::KernelMemory, true);
 698
 699     if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
 700       MPM.addPass(ModuleThreadSanitizerPass());
 701       MPM.addPass(createModuleToFunctionPassAdaptor(ThreadSanitizerPass()));
 702     }
 703
 704     auto ASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
 705       if (LangOpts.Sanitize.has(Mask)) {
 706         bool UseGlobalGC = asanUseGlobalsGC(TargetTriple, CodeGenOpts);
 707         bool UseOdrIndicator = CodeGenOpts.SanitizeAddressUseOdrIndicator;
 708         llvm::AsanDtorKind DestructorKind =
 709             CodeGenOpts.getSanitizeAddressDtor();
 710         AddressSanitizerOptions Opts;
 711         Opts.CompileKernel = CompileKernel;
 712         Opts.Recover = CodeGenOpts.SanitizeRecover.has(Mask);
 713         Opts.UseAfterScope = CodeGenOpts.SanitizeAddressUseAfterScope;
 714         Opts.UseAfterReturn = CodeGenOpts.getSanitizeAddressUseAfterReturn();
 715         MPM.addPass(AddressSanitizerPass(Opts, UseGlobalGC, UseOdrIndicator,
 716                                          DestructorKind));
 717       }
 718     };
 719     ASanPass(SanitizerKind::Address, false);
 720     ASanPass(SanitizerKind::KernelAddress, true);
 721
 722     auto HWASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
 723       if (LangOpts.Sanitize.has(Mask)) {
 724         bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
 725         MPM.addPass(HWAddressSanitizerPass(
 726             {CompileKernel, Recover,
 727              /*DisableOptimization=*/CodeGenOpts.OptimizationLevel == 0}));
 728       }
 729     };
 730     HWASanPass(SanitizerKind::HWAddress, false);
 731     HWASanPass(SanitizerKind::KernelHWAddress, true);
 732
 733     if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
 734       MPM.addPass(DataFlowSanitizerPass(LangOpts.NoSanitizeFiles));
 735     }
 736   };
 737   if (ClSanitizeOnOptimizerEarlyEP) {
 738     PB.registerOptimizerEarlyEPCallback(
 739         [SanitizersCallback](ModulePassManager &MPM, OptimizationLevel Level) {
 740           ModulePassManager NewMPM;
 741           SanitizersCallback(NewMPM, Level);
 742           if (!NewMPM.isEmpty()) {
 743             // Sanitizers can abandon<GlobalsAA>.
 744             NewMPM.addPass(RequireAnalysisPass<GlobalsAA, Module>());
 745             MPM.addPass(std::move(NewMPM));
 746           }
 747         });
 748   } else {
 749     // LastEP does not need GlobalsAA.
 750     PB.registerOptimizerLastEPCallback(SanitizersCallback);
 751   }
 752 }
 753
 754 void EmitAssemblyHelper::RunOptimizationPipeline(
 755     BackendAction Action, std::unique_ptr<raw_pwrite_stream> &OS,
 756     std::unique_ptr<llvm::ToolOutputFile> &ThinLinkOS) {
 757   std::optional<PGOOptions> PGOOpt;
 758
 759   if (CodeGenOpts.hasProfileIRInstr())
 760     // -fprofile-generate.
 761     PGOOpt = PGOOptions(
 762         CodeGenOpts.InstrProfileOutput.empty() ? getDefaultProfileGenName()
 763                                                : CodeGenOpts.InstrProfileOutput,
 764         "", "", nullptr, PGOOptions::IRInstr, PGOOptions::NoCSAction,
 765         CodeGenOpts.DebugInfoForProfiling);
 766   else if (CodeGenOpts.hasProfileIRUse()) {
 767     // -fprofile-use.
 768     auto CSAction = CodeGenOpts.hasProfileCSIRUse() ? PGOOptions::CSIRUse
 769                                                     : PGOOptions::NoCSAction;
 770     PGOOpt =
 771         PGOOptions(CodeGenOpts.ProfileInstrumentUsePath, "",
 772                    CodeGenOpts.ProfileRemappingFile, VFS, PGOOptions::IRUse,
 773                    CSAction, CodeGenOpts.DebugInfoForProfiling);
 774   } else if (!CodeGenOpts.SampleProfileFile.empty())
 775     // -fprofile-sample-use
 776     PGOOpt = PGOOptions(
 777         CodeGenOpts.SampleProfileFile, "", CodeGenOpts.ProfileRemappingFile,
 778         VFS, PGOOptions::SampleUse, PGOOptions::NoCSAction,
 779         CodeGenOpts.DebugInfoForProfiling, CodeGenOpts.PseudoProbeForProfiling);
 780   else if (CodeGenOpts.PseudoProbeForProfiling)
 781     // -fpseudo-probe-for-profiling
 782     PGOOpt = PGOOptions("", "", "", nullptr, PGOOptions::NoAction,
 783                         PGOOptions::NoCSAction,
 784                         CodeGenOpts.DebugInfoForProfiling, true);
 785   else if (CodeGenOpts.DebugInfoForProfiling)
 786     // -fdebug-info-for-profiling
 787     PGOOpt = PGOOptions("", "", "", nullptr, PGOOptions::NoAction,
 788                         PGOOptions::NoCSAction, true);
 789
 790   // Check to see if we want to generate a CS profile.
 791   if (CodeGenOpts.hasProfileCSIRInstr()) {
 792     assert(!CodeGenOpts.hasProfileCSIRUse() &&
 793            "Cannot have both CSProfileUse pass and CSProfileGen pass at "
 794            "the same time");
 795     if (PGOOpt) {
 796       assert(PGOOpt->Action != PGOOptions::IRInstr &&
 797              PGOOpt->Action != PGOOptions::SampleUse &&
 798              "Cannot run CSProfileGen pass with ProfileGen or SampleUse "
 799              " pass");
 800       PGOOpt->CSProfileGenFile = CodeGenOpts.InstrProfileOutput.empty()
 801                                      ? getDefaultProfileGenName()
 802                                      : CodeGenOpts.InstrProfileOutput;
 803       PGOOpt->CSAction = PGOOptions::CSIRInstr;
 804     } else
 805       PGOOpt =
 806           PGOOptions("",
 807                      CodeGenOpts.InstrProfileOutput.empty()
 808                          ? getDefaultProfileGenName()
 809                          : CodeGenOpts.InstrProfileOutput,
 810                      "", nullptr, PGOOptions::NoAction, PGOOptions::CSIRInstr,
 811                      CodeGenOpts.DebugInfoForProfiling);
 812   }
 813   if (TM)
 814     TM->setPGOOption(PGOOpt);
 815
 816   PipelineTuningOptions PTO;
 817   PTO.LoopUnrolling = CodeGenOpts.UnrollLoops;
 818   // For historical reasons, loop interleaving is set to mirror setting for loop
 819   // unrolling.
 820   PTO.LoopInterleaving = CodeGenOpts.UnrollLoops;
 821   PTO.LoopVectorization = CodeGenOpts.VectorizeLoop;
 822   PTO.SLPVectorization = CodeGenOpts.VectorizeSLP;
 823   PTO.MergeFunctions = CodeGenOpts.MergeFunctions;
 824   // Only enable CGProfilePass when using integrated assembler, since
 825   // non-integrated assemblers don't recognize .cgprofile section.
 826   PTO.CallGraphProfile = !CodeGenOpts.DisableIntegratedAS;
 827
 828   LoopAnalysisManager LAM;
 829   FunctionAnalysisManager FAM;
 830   CGSCCAnalysisManager CGAM;
 831   ModuleAnalysisManager MAM;
 832
 833   bool DebugPassStructure = CodeGenOpts.DebugPass == "Structure";
 834   PassInstrumentationCallbacks PIC;
 835   PrintPassOptions PrintPassOpts;
 836   PrintPassOpts.Indent = DebugPassStructure;
 837   PrintPassOpts.SkipAnalyses = DebugPassStructure;
 838   StandardInstrumentations SI(
 839       TheModule->getContext(),
 840       (CodeGenOpts.DebugPassManager || DebugPassStructure),
 841       /*VerifyEach*/ false, PrintPassOpts);
 842   SI.registerCallbacks(PIC, &FAM);
 843   PassBuilder PB(TM.get(), PTO, PGOOpt, &PIC);
 844
 845   if (CodeGenOpts.EnableAssignmentTracking) {
 846     PB.registerPipelineStartEPCallback(
 847         [&](ModulePassManager &MPM, OptimizationLevel Level) {
 848           MPM.addPass(AssignmentTrackingPass());
 849         });
 850   }
 851
 852   // Enable verify-debuginfo-preserve-each for new PM.
 853   DebugifyEachInstrumentation Debugify;
 854   DebugInfoPerPass DebugInfoBeforePass;
 855   if (CodeGenOpts.EnableDIPreservationVerify) {
 856     Debugify.setDebugifyMode(DebugifyMode::OriginalDebugInfo);
 857     Debugify.setDebugInfoBeforePass(DebugInfoBeforePass);
 858
 859     if (!CodeGenOpts.DIBugsReportFilePath.empty())
 860       Debugify.setOrigDIVerifyBugsReportFilePath(
 861           CodeGenOpts.DIBugsReportFilePath);
 862     Debugify.registerCallbacks(PIC);
 863   }
 864   // Attempt to load pass plugins and register their callbacks with PB.
 865   for (auto &PluginFN : CodeGenOpts.PassPlugins) {
 866     auto PassPlugin = PassPlugin::Load(PluginFN);
 867     if (PassPlugin) {
 868       PassPlugin->registerPassBuilderCallbacks(PB);
 869     } else {
 870       Diags.Report(diag::err_fe_unable_to_load_plugin)
 871           << PluginFN << toString(PassPlugin.takeError());
 872     }
 873   }
 874 #define HANDLE_EXTENSION(Ext)                                                  \
 875   get##Ext##PluginInfo().RegisterPassBuilderCallbacks(PB);
 876 #include "llvm/Support/Extension.def"
 877
 878   // Register the target library analysis directly and give it a customized
 879   // preset TLI.
 880   std::unique_ptr<TargetLibraryInfoImpl> TLII(
 881       createTLII(TargetTriple, CodeGenOpts));
 882   FAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); });
 883
 884   // Register all the basic analyses with the managers.
 885   PB.registerModuleAnalyses(MAM);
 886   PB.registerCGSCCAnalyses(CGAM);
 887   PB.registerFunctionAnalyses(FAM);
 888   PB.registerLoopAnalyses(LAM);
 889   PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
 890
 891   ModulePassManager MPM;
 892
 893   if (!CodeGenOpts.DisableLLVMPasses) {
 894     // Map our optimization levels into one of the distinct levels used to
 895     // configure the pipeline.
 896     OptimizationLevel Level = mapToLevel(CodeGenOpts);
 897
 898     bool IsThinLTO = CodeGenOpts.PrepareForThinLTO;
 899     bool IsLTO = CodeGenOpts.PrepareForLTO;
 900
 901     if (LangOpts.ObjCAutoRefCount) {
 902       PB.registerPipelineStartEPCallback(
 903           [](ModulePassManager &MPM, OptimizationLevel Level) {
 904             if (Level != OptimizationLevel::O0)
 905               MPM.addPass(
 906                   createModuleToFunctionPassAdaptor(ObjCARCExpandPass()));
 907           });
 908       PB.registerPipelineEarlySimplificationEPCallback(
 909           [](ModulePassManager &MPM, OptimizationLevel Level) {
 910             if (Level != OptimizationLevel::O0)
 911               MPM.addPass(ObjCARCAPElimPass());
 912           });
 913       PB.registerScalarOptimizerLateEPCallback(
 914           [](FunctionPassManager &FPM, OptimizationLevel Level) {
 915             if (Level != OptimizationLevel::O0)
 916               FPM.addPass(ObjCARCOptPass());
 917           });
 918     }
 919
 920     // If we reached here with a non-empty index file name, then the index
 921     // file was empty and we are not performing ThinLTO backend compilation
 922     // (used in testing in a distributed build environment).
 923     bool IsThinLTOPostLink = !CodeGenOpts.ThinLTOIndexFile.empty();
 924     // If so drop any the type test assume sequences inserted for whole program
 925     // vtables so that codegen doesn't complain.
 926     if (IsThinLTOPostLink)
 927       PB.registerPipelineStartEPCallback(
 928           [](ModulePassManager &MPM, OptimizationLevel Level) {
 929             MPM.addPass(LowerTypeTestsPass(/*ExportSummary=*/nullptr,
 930                                            /*ImportSummary=*/nullptr,
 931                                            /*DropTypeTests=*/true));
 932           });
 933
 934     if (CodeGenOpts.InstrumentFunctions ||
 935         CodeGenOpts.InstrumentFunctionEntryBare ||
 936         CodeGenOpts.InstrumentFunctionsAfterInlining ||
 937         CodeGenOpts.InstrumentForProfiling) {
 938       PB.registerPipelineStartEPCallback(
 939           [](ModulePassManager &MPM, OptimizationLevel Level) {
 940             MPM.addPass(createModuleToFunctionPassAdaptor(
 941                 EntryExitInstrumenterPass(/*PostInlining=*/false)));
 942           });
 943       PB.registerOptimizerLastEPCallback(
 944           [](ModulePassManager &MPM, OptimizationLevel Level) {
 945             MPM.addPass(createModuleToFunctionPassAdaptor(
 946                 EntryExitInstrumenterPass(/*PostInlining=*/true)));
 947           });
 948     }
 949
 950     // Register callbacks to schedule sanitizer passes at the appropriate part
 951     // of the pipeline.
 952     if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
 953       PB.registerScalarOptimizerLateEPCallback(
 954           [](FunctionPassManager &FPM, OptimizationLevel Level) {
 955             FPM.addPass(BoundsCheckingPass());
 956           });
 957
 958     // Don't add sanitizers if we are here from ThinLTO PostLink. That already
 959     // done on PreLink stage.
 960     if (!IsThinLTOPostLink) {
 961       addSanitizers(TargetTriple, CodeGenOpts, LangOpts, PB);
 962       addKCFIPass(TargetTriple, LangOpts, PB);
 963     }
 964
 965     if (std::optional<GCOVOptions> Options =
 966             getGCOVOptions(CodeGenOpts, LangOpts))
 967       PB.registerPipelineStartEPCallback(
 968           [Options](ModulePassManager &MPM, OptimizationLevel Level) {
 969             MPM.addPass(GCOVProfilerPass(*Options));
 970           });
 971     if (std::optional<InstrProfOptions> Options =
 972             getInstrProfOptions(CodeGenOpts, LangOpts))
 973       PB.registerPipelineStartEPCallback(
 974           [Options](ModulePassManager &MPM, OptimizationLevel Level) {
 975             MPM.addPass(InstrProfiling(*Options, false));
 976           });
 977
 978     if (CodeGenOpts.OptimizationLevel == 0) {
 979       MPM = PB.buildO0DefaultPipeline(Level, IsLTO || IsThinLTO);
 980     } else if (IsThinLTO) {
 981       MPM = PB.buildThinLTOPreLinkDefaultPipeline(Level);
 982     } else if (IsLTO) {
 983       MPM = PB.buildLTOPreLinkDefaultPipeline(Level);
 984     } else {
 985       MPM = PB.buildPerModuleDefaultPipeline(Level);
 986     }
 987
 988     if (!CodeGenOpts.MemoryProfileOutput.empty()) {
 989       MPM.addPass(createModuleToFunctionPassAdaptor(MemProfilerPass()));
 990       MPM.addPass(ModuleMemProfilerPass());
 991     }
 992   }
 993
 994   // Add a verifier pass if requested. We don't have to do this if the action
 995   // requires code generation because there will already be a verifier pass in
 996   // the code-generation pipeline.
 997   if (!actionRequiresCodeGen(Action) && CodeGenOpts.VerifyModule)
 998     MPM.addPass(VerifierPass());
 999
1000   if (Action == Backend_EmitBC || Action == Backend_EmitLL) {
1001     if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
1002       if (!TheModule->getModuleFlag("EnableSplitLTOUnit"))
1003         TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1004                                  CodeGenOpts.EnableSplitLTOUnit);
1005       if (Action == Backend_EmitBC) {
1006         if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
1007           ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
1008           if (!ThinLinkOS)
1009             return;
1010         }
1011         MPM.addPass(ThinLTOBitcodeWriterPass(*OS, ThinLinkOS ? &ThinLinkOS->os()
1012                                                              : nullptr));
1013       } else {
1014         MPM.addPass(PrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists,
1015                                     /*EmitLTOSummary=*/true));
1016       }
1017
1018     } else {
1019       // Emit a module summary by default for Regular LTO except for ld64
1020       // targets
1021       bool EmitLTOSummary = shouldEmitRegularLTOSummary();
1022       if (EmitLTOSummary) {
1023         if (!TheModule->getModuleFlag("ThinLTO"))
1024           TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
1025         if (!TheModule->getModuleFlag("EnableSplitLTOUnit"))
1026           TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1027                                    uint32_t(1));
1028       }
1029       if (Action == Backend_EmitBC)
1030         MPM.addPass(BitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists,
1031                                       EmitLTOSummary));
1032       else
1033         MPM.addPass(PrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists,
1034                                     EmitLTOSummary));
1035     }
1036   }
1037
1038   // Now that we have all of the passes ready, run them.
1039   {
1040     PrettyStackTraceString CrashInfo("Optimizer");
1041     llvm::TimeTraceScope TimeScope("Optimizer");
1042     MPM.run(*TheModule, MAM);
1043   }
1044 }
1045
1046 void EmitAssemblyHelper::RunCodegenPipeline(
1047     BackendAction Action, std::unique_ptr<raw_pwrite_stream> &OS,
1048     std::unique_ptr<llvm::ToolOutputFile> &DwoOS) {
1049   // We still use the legacy PM to run the codegen pipeline since the new PM
1050   // does not work with the codegen pipeline.
1051   // FIXME: make the new PM work with the codegen pipeline.
1052   legacy::PassManager CodeGenPasses;
1053
1054   // Append any output we need to the pass manager.
1055   switch (Action) {
1056   case Backend_EmitAssembly:
1057   case Backend_EmitMCNull:
1058   case Backend_EmitObj:
1059     CodeGenPasses.add(
1060         createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
1061     if (!CodeGenOpts.SplitDwarfOutput.empty()) {
1062       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
1063       if (!DwoOS)
1064         return;
1065     }
1066     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
1067                        DwoOS ? &DwoOS->os() : nullptr))
1068       // FIXME: Should we handle this error differently?
1069       return;
1070     break;
1071   default:
1072     return;
1073   }
1074
1075   {
1076     PrettyStackTraceString CrashInfo("Code generation");
1077     llvm::TimeTraceScope TimeScope("CodeGenPasses");
1078     CodeGenPasses.run(*TheModule);
1079   }
1080 }
1081
1082 void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
1083                                       std::unique_ptr<raw_pwrite_stream> OS) {
1084   TimeRegion Region(CodeGenOpts.TimePasses ? &CodeGenerationTime : nullptr);
1085   setCommandLineOpts(CodeGenOpts);
1086
1087   bool RequiresCodeGen = actionRequiresCodeGen(Action);
1088   CreateTargetMachine(RequiresCodeGen);
1089
1090   if (RequiresCodeGen && !TM)
1091     return;
1092   if (TM)
1093     TheModule->setDataLayout(TM->createDataLayout());
1094
1095   // Before executing passes, print the final values of the LLVM options.
1096   cl::PrintOptionValues();
1097
1098   std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
1099   RunOptimizationPipeline(Action, OS, ThinLinkOS);
1100   RunCodegenPipeline(Action, OS, DwoOS);
1101
1102   if (ThinLinkOS)
1103     ThinLinkOS->keep();
1104   if (DwoOS)
1105     DwoOS->keep();
1106 }
1107
1108 static void runThinLTOBackend(
1109     DiagnosticsEngine &Diags, ModuleSummaryIndex *CombinedIndex, Module *M,
1110     const HeaderSearchOptions &HeaderOpts, const CodeGenOptions &CGOpts,
1111     const clang::TargetOptions &TOpts, const LangOptions &LOpts,
1112     std::unique_ptr<raw_pwrite_stream> OS, std::string SampleProfile,
1113     std::string ProfileRemapping, BackendAction Action) {
1114   StringMap<DenseMap<GlobalValue::GUID, GlobalValueSummary *>>
1115       ModuleToDefinedGVSummaries;
1116   CombinedIndex->collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries);
1117
1118   setCommandLineOpts(CGOpts);
1119
1120   // We can simply import the values mentioned in the combined index, since
1121   // we should only invoke this using the individual indexes written out
1122   // via a WriteIndexesThinBackend.
1123   FunctionImporter::ImportMapTy ImportList;
1124   if (!lto::initImportList(*M, *CombinedIndex, ImportList))
1125     return;
1126
1127   auto AddStream = [&](size_t Task, const Twine &ModuleName) {
1128     return std::make_unique<CachedFileStream>(std::move(OS),
1129                                               CGOpts.ObjectFilenameForDebug);
1130   };
1131   lto::Config Conf;
1132   if (CGOpts.SaveTempsFilePrefix != "") {
1133     if (Error E = Conf.addSaveTemps(CGOpts.SaveTempsFilePrefix + ".",
1134                                     /* UseInputModulePath */ false)) {
1135       handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1136         errs() << "Error setting up ThinLTO save-temps: " << EIB.message()
1137                << '\n';
1138       });
1139     }
1140   }
1141   Conf.CPU = TOpts.CPU;
1142   Conf.CodeModel = getCodeModel(CGOpts);
1143   Conf.MAttrs = TOpts.Features;
1144   Conf.RelocModel = CGOpts.RelocationModel;
1145   std::optional<CodeGenOpt::Level> OptLevelOrNone =
1146       CodeGenOpt::getLevel(CGOpts.OptimizationLevel);
1147   assert(OptLevelOrNone && "Invalid optimization level!");
1148   Conf.CGOptLevel = *OptLevelOrNone;
1149   Conf.OptLevel = CGOpts.OptimizationLevel;
1150   initTargetOptions(Diags, Conf.Options, CGOpts, TOpts, LOpts, HeaderOpts);
1151   Conf.SampleProfile = std::move(SampleProfile);
1152   Conf.PTO.LoopUnrolling = CGOpts.UnrollLoops;
1153   // For historical reasons, loop interleaving is set to mirror setting for loop
1154   // unrolling.
1155   Conf.PTO.LoopInterleaving = CGOpts.UnrollLoops;
1156   Conf.PTO.LoopVectorization = CGOpts.VectorizeLoop;
1157   Conf.PTO.SLPVectorization = CGOpts.VectorizeSLP;
1158   // Only enable CGProfilePass when using integrated assembler, since
1159   // non-integrated assemblers don't recognize .cgprofile section.
1160   Conf.PTO.CallGraphProfile = !CGOpts.DisableIntegratedAS;
1161
1162   // Context sensitive profile.
1163   if (CGOpts.hasProfileCSIRInstr()) {
1164     Conf.RunCSIRInstr = true;
1165     Conf.CSIRProfile = std::move(CGOpts.InstrProfileOutput);
1166   } else if (CGOpts.hasProfileCSIRUse()) {
1167     Conf.RunCSIRInstr = false;
1168     Conf.CSIRProfile = std::move(CGOpts.ProfileInstrumentUsePath);
1169   }
1170
1171   Conf.ProfileRemapping = std::move(ProfileRemapping);
1172   Conf.DebugPassManager = CGOpts.DebugPassManager;
1173   Conf.RemarksWithHotness = CGOpts.DiagnosticsWithHotness;
1174   Conf.RemarksFilename = CGOpts.OptRecordFile;
1175   Conf.RemarksPasses = CGOpts.OptRecordPasses;
1176   Conf.RemarksFormat = CGOpts.OptRecordFormat;
1177   Conf.SplitDwarfFile = CGOpts.SplitDwarfFile;
1178   Conf.SplitDwarfOutput = CGOpts.SplitDwarfOutput;
1179   switch (Action) {
1180   case Backend_EmitNothing:
1181     Conf.PreCodeGenModuleHook = [](size_t Task, const Module &Mod) {
1182       return false;
1183     };
1184     break;
1185   case Backend_EmitLL:
1186     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1187       M->print(*OS, nullptr, CGOpts.EmitLLVMUseLists);
1188       return false;
1189     };
1190     break;
1191   case Backend_EmitBC:
1192     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1193       WriteBitcodeToFile(*M, *OS, CGOpts.EmitLLVMUseLists);
1194       return false;
1195     };
1196     break;
1197   default:
1198     Conf.CGFileType = getCodeGenFileType(Action);
1199     break;
1200   }
1201   if (Error E =
1202           thinBackend(Conf, -1, AddStream, *M, *CombinedIndex, ImportList,
1203                       ModuleToDefinedGVSummaries[M->getModuleIdentifier()],
1204                       /* ModuleMap */ nullptr, CGOpts.CmdArgs)) {
1205     handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1206       errs() << "Error running ThinLTO backend: " << EIB.message() << '\n';
1207     });
1208   }
1209 }
1210
1211 void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
1212                               const HeaderSearchOptions &HeaderOpts,
1213                               const CodeGenOptions &CGOpts,
1214                               const clang::TargetOptions &TOpts,
1215                               const LangOptions &LOpts, StringRef TDesc,
1216                               Module *M, BackendAction Action,
1217                               IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS,
1218                               std::unique_ptr<raw_pwrite_stream> OS) {
1219
1220   llvm::TimeTraceScope TimeScope("Backend");
1221
1222   std::unique_ptr<llvm::Module> EmptyModule;
1223   if (!CGOpts.ThinLTOIndexFile.empty()) {
1224     // If we are performing a ThinLTO importing compile, load the function index
1225     // into memory and pass it into runThinLTOBackend, which will run the
1226     // function importer and invoke LTO passes.
1227     std::unique_ptr<ModuleSummaryIndex> CombinedIndex;
1228     if (Error E = llvm::getModuleSummaryIndexForFile(
1229                       CGOpts.ThinLTOIndexFile,
1230                       /*IgnoreEmptyThinLTOIndexFile*/ true)
1231                       .moveInto(CombinedIndex)) {
1232       logAllUnhandledErrors(std::move(E), errs(),
1233                             "Error loading index file '" +
1234                             CGOpts.ThinLTOIndexFile + "': ");
1235       return;
1236     }
1237
1238     // A null CombinedIndex means we should skip ThinLTO compilation
1239     // (LLVM will optionally ignore empty index files, returning null instead
1240     // of an error).
1241     if (CombinedIndex) {
1242       if (!CombinedIndex->skipModuleByDistributedBackend()) {
1243         runThinLTOBackend(Diags, CombinedIndex.get(), M, HeaderOpts, CGOpts,
1244                           TOpts, LOpts, std::move(OS), CGOpts.SampleProfileFile,
1245                           CGOpts.ProfileRemappingFile, Action);
1246         return;
1247       }
1248       // Distributed indexing detected that nothing from the module is needed
1249       // for the final linking. So we can skip the compilation. We sill need to
1250       // output an empty object file to make sure that a linker does not fail
1251       // trying to read it. Also for some features, like CFI, we must skip
1252       // the compilation as CombinedIndex does not contain all required
1253       // information.
1254       EmptyModule = std::make_unique<llvm::Module>("empty", M->getContext());
1255       EmptyModule->setTargetTriple(M->getTargetTriple());
1256       M = EmptyModule.get();
1257     }
1258   }
1259
1260   EmitAssemblyHelper AsmHelper(Diags, HeaderOpts, CGOpts, TOpts, LOpts, M, VFS);
1261   AsmHelper.EmitAssembly(Action, std::move(OS));
1262
1263   // Verify clang's TargetInfo DataLayout against the LLVM TargetMachine's
1264   // DataLayout.
1265   if (AsmHelper.TM) {
1266     std::string DLDesc = M->getDataLayout().getStringRepresentation();
1267     if (DLDesc != TDesc) {
1268       unsigned DiagID = Diags.getCustomDiagID(
1269           DiagnosticsEngine::Error, "backend data layout '%0' does not match "
1270                                     "expected target description '%1'");
1271       Diags.Report(DiagID) << DLDesc << TDesc;
1272     }
1273   }
1274 }
1275
1276 // With -fembed-bitcode, save a copy of the llvm IR as data in the
1277 // __LLVM,__bitcode section.
1278 void clang::EmbedBitcode(llvm::Module *M, const CodeGenOptions &CGOpts,
1279                          llvm::MemoryBufferRef Buf) {
1280   if (CGOpts.getEmbedBitcode() == CodeGenOptions::Embed_Off)
1281     return;
1282   llvm::embedBitcodeInModule(
1283       *M, Buf, CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Marker,
1284       CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Bitcode,
1285       CGOpts.CmdArgs);
1286 }
1287
1288 void clang::EmbedObject(llvm::Module *M, const CodeGenOptions &CGOpts,
1289                         DiagnosticsEngine &Diags) {
1290   if (CGOpts.OffloadObjects.empty())
1291     return;
1292
1293   for (StringRef OffloadObject : CGOpts.OffloadObjects) {
1294     llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> ObjectOrErr =
1295         llvm::MemoryBuffer::getFileOrSTDIN(OffloadObject);
1296     if (std::error_code EC = ObjectOrErr.getError()) {
1297       auto DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
1298                                           "could not open '%0' for embedding");
1299       Diags.Report(DiagID) << OffloadObject;
1300       return;
1301     }
1302
1303     llvm::embedBufferInModule(*M, **ObjectOrErr, ".llvm.offloading",
1304                               Align(object::OffloadBinary::getAlignment()));
1305   }
1306 }