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/ADT/Triple.h"
21 #include "llvm/Analysis/StackSafetyAnalysis.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/IRPrintingPasses.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/LTO/LTOBackend.h"
38 #include "llvm/MC/MCAsmInfo.h"
39 #include "llvm/MC/SubtargetFeature.h"
40 #include "llvm/Passes/PassBuilder.h"
41 #include "llvm/Passes/PassPlugin.h"
42 #include "llvm/Passes/StandardInstrumentations.h"
43 #include "llvm/Support/BuryPointer.h"
44 #include "llvm/Support/CommandLine.h"
45 #include "llvm/Support/MemoryBuffer.h"
46 #include "llvm/Support/PrettyStackTrace.h"
47 #include "llvm/Support/TargetRegistry.h"
48 #include "llvm/Support/TimeProfiler.h"
49 #include "llvm/Support/Timer.h"
50 #include "llvm/Support/ToolOutputFile.h"
51 #include "llvm/Support/raw_ostream.h"
52 #include "llvm/Target/TargetMachine.h"
53 #include "llvm/Target/TargetOptions.h"
54 #include "llvm/Transforms/Coroutines.h"
55 #include "llvm/Transforms/Coroutines/CoroCleanup.h"
56 #include "llvm/Transforms/Coroutines/CoroEarly.h"
57 #include "llvm/Transforms/Coroutines/CoroElide.h"
58 #include "llvm/Transforms/Coroutines/CoroSplit.h"
59 #include "llvm/Transforms/IPO.h"
60 #include "llvm/Transforms/IPO/AlwaysInliner.h"
61 #include "llvm/Transforms/IPO/LowerTypeTests.h"
62 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
63 #include "llvm/Transforms/IPO/ThinLTOBitcodeWriter.h"
64 #include "llvm/Transforms/InstCombine/InstCombine.h"
65 #include "llvm/Transforms/Instrumentation.h"
66 #include "llvm/Transforms/Instrumentation/AddressSanitizer.h"
67 #include "llvm/Transforms/Instrumentation/BoundsChecking.h"
68 #include "llvm/Transforms/Instrumentation/DataFlowSanitizer.h"
69 #include "llvm/Transforms/Instrumentation/GCOVProfiler.h"
70 #include "llvm/Transforms/Instrumentation/HWAddressSanitizer.h"
71 #include "llvm/Transforms/Instrumentation/InstrProfiling.h"
72 #include "llvm/Transforms/Instrumentation/MemProfiler.h"
73 #include "llvm/Transforms/Instrumentation/MemorySanitizer.h"
74 #include "llvm/Transforms/Instrumentation/SanitizerCoverage.h"
75 #include "llvm/Transforms/Instrumentation/ThreadSanitizer.h"
76 #include "llvm/Transforms/ObjCARC.h"
77 #include "llvm/Transforms/Scalar.h"
78 #include "llvm/Transforms/Scalar/GVN.h"
79 #include "llvm/Transforms/Scalar/LowerMatrixIntrinsics.h"
80 #include "llvm/Transforms/Utils.h"
81 #include "llvm/Transforms/Utils/CanonicalizeAliases.h"
82 #include "llvm/Transforms/Utils/EntryExitInstrumenter.h"
83 #include "llvm/Transforms/Utils/NameAnonGlobals.h"
84 #include "llvm/Transforms/Utils/SymbolRewriter.h"
85 #include "llvm/Transforms/Utils/UniqueInternalLinkageNames.h"
86 #include <memory>
87 using namespace clang;
88 using namespace llvm;
89 
90 #define HANDLE_EXTENSION(Ext)                                                  \
91   llvm::PassPluginLibraryInfo get##Ext##PluginInfo();
92 #include "llvm/Support/Extension.def"
93 
94 namespace {
95 
96 // Default filename used for profile generation.
97 static constexpr StringLiteral DefaultProfileGenName = "default_%m.profraw";
98 
99 class EmitAssemblyHelper {
100   DiagnosticsEngine &Diags;
101   const HeaderSearchOptions &HSOpts;
102   const CodeGenOptions &CodeGenOpts;
103   const clang::TargetOptions &TargetOpts;
104   const LangOptions &LangOpts;
105   Module *TheModule;
106 
107   Timer CodeGenerationTime;
108 
109   std::unique_ptr<raw_pwrite_stream> OS;
110 
111   TargetIRAnalysis getTargetIRAnalysis() const {
112     if (TM)
113       return TM->getTargetIRAnalysis();
114 
115     return TargetIRAnalysis();
116   }
117 
118   void CreatePasses(legacy::PassManager &MPM, legacy::FunctionPassManager &FPM);
119 
120   /// Generates the TargetMachine.
121   /// Leaves TM unchanged if it is unable to create the target machine.
122   /// Some of our clang tests specify triples which are not built
123   /// into clang. This is okay because these tests check the generated
124   /// IR, and they require DataLayout which depends on the triple.
125   /// In this case, we allow this method to fail and not report an error.
126   /// When MustCreateTM is used, we print an error if we are unable to load
127   /// the requested target.
128   void CreateTargetMachine(bool MustCreateTM);
129 
130   /// Add passes necessary to emit assembly or LLVM IR.
131   ///
132   /// \return True on success.
133   bool AddEmitPasses(legacy::PassManager &CodeGenPasses, BackendAction Action,
134                      raw_pwrite_stream &OS, raw_pwrite_stream *DwoOS);
135 
136   std::unique_ptr<llvm::ToolOutputFile> openOutputFile(StringRef Path) {
137     std::error_code EC;
138     auto F = std::make_unique<llvm::ToolOutputFile>(Path, EC,
139                                                      llvm::sys::fs::OF_None);
140     if (EC) {
141       Diags.Report(diag::err_fe_unable_to_open_output) << Path << EC.message();
142       F.reset();
143     }
144     return F;
145   }
146 
147 public:
148   EmitAssemblyHelper(DiagnosticsEngine &_Diags,
149                      const HeaderSearchOptions &HeaderSearchOpts,
150                      const CodeGenOptions &CGOpts,
151                      const clang::TargetOptions &TOpts,
152                      const LangOptions &LOpts, Module *M)
153       : Diags(_Diags), HSOpts(HeaderSearchOpts), CodeGenOpts(CGOpts),
154         TargetOpts(TOpts), LangOpts(LOpts), TheModule(M),
155         CodeGenerationTime("codegen", "Code Generation Time") {}
156 
157   ~EmitAssemblyHelper() {
158     if (CodeGenOpts.DisableFree)
159       BuryPointer(std::move(TM));
160   }
161 
162   std::unique_ptr<TargetMachine> TM;
163 
164   void EmitAssembly(BackendAction Action,
165                     std::unique_ptr<raw_pwrite_stream> OS);
166 
167   void EmitAssemblyWithNewPassManager(BackendAction Action,
168                                       std::unique_ptr<raw_pwrite_stream> OS);
169 };
170 
171 // We need this wrapper to access LangOpts and CGOpts from extension functions
172 // that we add to the PassManagerBuilder.
173 class PassManagerBuilderWrapper : public PassManagerBuilder {
174 public:
175   PassManagerBuilderWrapper(const Triple &TargetTriple,
176                             const CodeGenOptions &CGOpts,
177                             const LangOptions &LangOpts)
178       : PassManagerBuilder(), TargetTriple(TargetTriple), CGOpts(CGOpts),
179         LangOpts(LangOpts) {}
180   const Triple &getTargetTriple() const { return TargetTriple; }
181   const CodeGenOptions &getCGOpts() const { return CGOpts; }
182   const LangOptions &getLangOpts() const { return LangOpts; }
183 
184 private:
185   const Triple &TargetTriple;
186   const CodeGenOptions &CGOpts;
187   const LangOptions &LangOpts;
188 };
189 }
190 
191 static void addObjCARCAPElimPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
192   if (Builder.OptLevel > 0)
193     PM.add(createObjCARCAPElimPass());
194 }
195 
196 static void addObjCARCExpandPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
197   if (Builder.OptLevel > 0)
198     PM.add(createObjCARCExpandPass());
199 }
200 
201 static void addObjCARCOptPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
202   if (Builder.OptLevel > 0)
203     PM.add(createObjCARCOptPass());
204 }
205 
206 static void addAddDiscriminatorsPass(const PassManagerBuilder &Builder,
207                                      legacy::PassManagerBase &PM) {
208   PM.add(createAddDiscriminatorsPass());
209 }
210 
211 static void addBoundsCheckingPass(const PassManagerBuilder &Builder,
212                                   legacy::PassManagerBase &PM) {
213   PM.add(createBoundsCheckingLegacyPass());
214 }
215 
216 static SanitizerCoverageOptions
217 getSancovOptsFromCGOpts(const CodeGenOptions &CGOpts) {
218   SanitizerCoverageOptions Opts;
219   Opts.CoverageType =
220       static_cast<SanitizerCoverageOptions::Type>(CGOpts.SanitizeCoverageType);
221   Opts.IndirectCalls = CGOpts.SanitizeCoverageIndirectCalls;
222   Opts.TraceBB = CGOpts.SanitizeCoverageTraceBB;
223   Opts.TraceCmp = CGOpts.SanitizeCoverageTraceCmp;
224   Opts.TraceDiv = CGOpts.SanitizeCoverageTraceDiv;
225   Opts.TraceGep = CGOpts.SanitizeCoverageTraceGep;
226   Opts.Use8bitCounters = CGOpts.SanitizeCoverage8bitCounters;
227   Opts.TracePC = CGOpts.SanitizeCoverageTracePC;
228   Opts.TracePCGuard = CGOpts.SanitizeCoverageTracePCGuard;
229   Opts.NoPrune = CGOpts.SanitizeCoverageNoPrune;
230   Opts.Inline8bitCounters = CGOpts.SanitizeCoverageInline8bitCounters;
231   Opts.InlineBoolFlag = CGOpts.SanitizeCoverageInlineBoolFlag;
232   Opts.PCTable = CGOpts.SanitizeCoveragePCTable;
233   Opts.StackDepth = CGOpts.SanitizeCoverageStackDepth;
234   return Opts;
235 }
236 
237 static void addSanitizerCoveragePass(const PassManagerBuilder &Builder,
238                                      legacy::PassManagerBase &PM) {
239   const PassManagerBuilderWrapper &BuilderWrapper =
240       static_cast<const PassManagerBuilderWrapper &>(Builder);
241   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
242   auto Opts = getSancovOptsFromCGOpts(CGOpts);
243   PM.add(createModuleSanitizerCoverageLegacyPassPass(
244       Opts, CGOpts.SanitizeCoverageAllowlistFiles,
245       CGOpts.SanitizeCoverageBlocklistFiles));
246 }
247 
248 // Check if ASan should use GC-friendly instrumentation for globals.
249 // First of all, there is no point if -fdata-sections is off (expect for MachO,
250 // where this is not a factor). Also, on ELF this feature requires an assembler
251 // extension that only works with -integrated-as at the moment.
252 static bool asanUseGlobalsGC(const Triple &T, const CodeGenOptions &CGOpts) {
253   if (!CGOpts.SanitizeAddressGlobalsDeadStripping)
254     return false;
255   switch (T.getObjectFormat()) {
256   case Triple::MachO:
257   case Triple::COFF:
258     return true;
259   case Triple::ELF:
260     return CGOpts.DataSections && !CGOpts.DisableIntegratedAS;
261   case Triple::GOFF:
262     llvm::report_fatal_error("ASan not implemented for GOFF");
263   case Triple::XCOFF:
264     llvm::report_fatal_error("ASan not implemented for XCOFF.");
265   case Triple::Wasm:
266   case Triple::UnknownObjectFormat:
267     break;
268   }
269   return false;
270 }
271 
272 static void addMemProfilerPasses(const PassManagerBuilder &Builder,
273                                  legacy::PassManagerBase &PM) {
274   PM.add(createMemProfilerFunctionPass());
275   PM.add(createModuleMemProfilerLegacyPassPass());
276 }
277 
278 static void addAddressSanitizerPasses(const PassManagerBuilder &Builder,
279                                       legacy::PassManagerBase &PM) {
280   const PassManagerBuilderWrapper &BuilderWrapper =
281       static_cast<const PassManagerBuilderWrapper&>(Builder);
282   const Triple &T = BuilderWrapper.getTargetTriple();
283   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
284   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Address);
285   bool UseAfterScope = CGOpts.SanitizeAddressUseAfterScope;
286   bool UseOdrIndicator = CGOpts.SanitizeAddressUseOdrIndicator;
287   bool UseGlobalsGC = asanUseGlobalsGC(T, CGOpts);
288   PM.add(createAddressSanitizerFunctionPass(/*CompileKernel*/ false, Recover,
289                                             UseAfterScope));
290   PM.add(createModuleAddressSanitizerLegacyPassPass(
291       /*CompileKernel*/ false, Recover, UseGlobalsGC, UseOdrIndicator));
292 }
293 
294 static void addKernelAddressSanitizerPasses(const PassManagerBuilder &Builder,
295                                             legacy::PassManagerBase &PM) {
296   PM.add(createAddressSanitizerFunctionPass(
297       /*CompileKernel*/ true, /*Recover*/ true, /*UseAfterScope*/ false));
298   PM.add(createModuleAddressSanitizerLegacyPassPass(
299       /*CompileKernel*/ true, /*Recover*/ true, /*UseGlobalsGC*/ true,
300       /*UseOdrIndicator*/ false));
301 }
302 
303 static void addHWAddressSanitizerPasses(const PassManagerBuilder &Builder,
304                                             legacy::PassManagerBase &PM) {
305   const PassManagerBuilderWrapper &BuilderWrapper =
306       static_cast<const PassManagerBuilderWrapper &>(Builder);
307   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
308   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::HWAddress);
309   PM.add(
310       createHWAddressSanitizerLegacyPassPass(/*CompileKernel*/ false, Recover));
311 }
312 
313 static void addKernelHWAddressSanitizerPasses(const PassManagerBuilder &Builder,
314                                             legacy::PassManagerBase &PM) {
315   PM.add(createHWAddressSanitizerLegacyPassPass(
316       /*CompileKernel*/ true, /*Recover*/ true));
317 }
318 
319 static void addGeneralOptsForMemorySanitizer(const PassManagerBuilder &Builder,
320                                              legacy::PassManagerBase &PM,
321                                              bool CompileKernel) {
322   const PassManagerBuilderWrapper &BuilderWrapper =
323       static_cast<const PassManagerBuilderWrapper&>(Builder);
324   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
325   int TrackOrigins = CGOpts.SanitizeMemoryTrackOrigins;
326   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Memory);
327   PM.add(createMemorySanitizerLegacyPassPass(
328       MemorySanitizerOptions{TrackOrigins, Recover, CompileKernel}));
329 
330   // MemorySanitizer inserts complex instrumentation that mostly follows
331   // the logic of the original code, but operates on "shadow" values.
332   // It can benefit from re-running some general purpose optimization passes.
333   if (Builder.OptLevel > 0) {
334     PM.add(createEarlyCSEPass());
335     PM.add(createReassociatePass());
336     PM.add(createLICMPass());
337     PM.add(createGVNPass());
338     PM.add(createInstructionCombiningPass());
339     PM.add(createDeadStoreEliminationPass());
340   }
341 }
342 
343 static void addMemorySanitizerPass(const PassManagerBuilder &Builder,
344                                    legacy::PassManagerBase &PM) {
345   addGeneralOptsForMemorySanitizer(Builder, PM, /*CompileKernel*/ false);
346 }
347 
348 static void addKernelMemorySanitizerPass(const PassManagerBuilder &Builder,
349                                          legacy::PassManagerBase &PM) {
350   addGeneralOptsForMemorySanitizer(Builder, PM, /*CompileKernel*/ true);
351 }
352 
353 static void addThreadSanitizerPass(const PassManagerBuilder &Builder,
354                                    legacy::PassManagerBase &PM) {
355   PM.add(createThreadSanitizerLegacyPassPass());
356 }
357 
358 static void addDataFlowSanitizerPass(const PassManagerBuilder &Builder,
359                                      legacy::PassManagerBase &PM) {
360   const PassManagerBuilderWrapper &BuilderWrapper =
361       static_cast<const PassManagerBuilderWrapper&>(Builder);
362   const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
363   PM.add(
364       createDataFlowSanitizerLegacyPassPass(LangOpts.SanitizerBlacklistFiles));
365 }
366 
367 static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
368                                          const CodeGenOptions &CodeGenOpts) {
369   TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple);
370 
371   switch (CodeGenOpts.getVecLib()) {
372   case CodeGenOptions::Accelerate:
373     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::Accelerate);
374     break;
375   case CodeGenOptions::LIBMVEC:
376     switch(TargetTriple.getArch()) {
377       default:
378         break;
379       case llvm::Triple::x86_64:
380         TLII->addVectorizableFunctionsFromVecLib
381                 (TargetLibraryInfoImpl::LIBMVEC_X86);
382         break;
383     }
384     break;
385   case CodeGenOptions::MASSV:
386     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::MASSV);
387     break;
388   case CodeGenOptions::SVML:
389     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::SVML);
390     break;
391   default:
392     break;
393   }
394   return TLII;
395 }
396 
397 static void addSymbolRewriterPass(const CodeGenOptions &Opts,
398                                   legacy::PassManager *MPM) {
399   llvm::SymbolRewriter::RewriteDescriptorList DL;
400 
401   llvm::SymbolRewriter::RewriteMapParser MapParser;
402   for (const auto &MapFile : Opts.RewriteMapFiles)
403     MapParser.parse(MapFile, &DL);
404 
405   MPM->add(createRewriteSymbolsPass(DL));
406 }
407 
408 static CodeGenOpt::Level getCGOptLevel(const CodeGenOptions &CodeGenOpts) {
409   switch (CodeGenOpts.OptimizationLevel) {
410   default:
411     llvm_unreachable("Invalid optimization level!");
412   case 0:
413     return CodeGenOpt::None;
414   case 1:
415     return CodeGenOpt::Less;
416   case 2:
417     return CodeGenOpt::Default; // O2/Os/Oz
418   case 3:
419     return CodeGenOpt::Aggressive;
420   }
421 }
422 
423 static Optional<llvm::CodeModel::Model>
424 getCodeModel(const CodeGenOptions &CodeGenOpts) {
425   unsigned CodeModel = llvm::StringSwitch<unsigned>(CodeGenOpts.CodeModel)
426                            .Case("tiny", llvm::CodeModel::Tiny)
427                            .Case("small", llvm::CodeModel::Small)
428                            .Case("kernel", llvm::CodeModel::Kernel)
429                            .Case("medium", llvm::CodeModel::Medium)
430                            .Case("large", llvm::CodeModel::Large)
431                            .Case("default", ~1u)
432                            .Default(~0u);
433   assert(CodeModel != ~0u && "invalid code model!");
434   if (CodeModel == ~1u)
435     return None;
436   return static_cast<llvm::CodeModel::Model>(CodeModel);
437 }
438 
439 static CodeGenFileType getCodeGenFileType(BackendAction Action) {
440   if (Action == Backend_EmitObj)
441     return CGFT_ObjectFile;
442   else if (Action == Backend_EmitMCNull)
443     return CGFT_Null;
444   else {
445     assert(Action == Backend_EmitAssembly && "Invalid action!");
446     return CGFT_AssemblyFile;
447   }
448 }
449 
450 static bool initTargetOptions(DiagnosticsEngine &Diags,
451                               llvm::TargetOptions &Options,
452                               const CodeGenOptions &CodeGenOpts,
453                               const clang::TargetOptions &TargetOpts,
454                               const LangOptions &LangOpts,
455                               const HeaderSearchOptions &HSOpts) {
456   switch (LangOpts.getThreadModel()) {
457   case LangOptions::ThreadModelKind::POSIX:
458     Options.ThreadModel = llvm::ThreadModel::POSIX;
459     break;
460   case LangOptions::ThreadModelKind::Single:
461     Options.ThreadModel = llvm::ThreadModel::Single;
462     break;
463   }
464 
465   // Set float ABI type.
466   assert((CodeGenOpts.FloatABI == "soft" || CodeGenOpts.FloatABI == "softfp" ||
467           CodeGenOpts.FloatABI == "hard" || CodeGenOpts.FloatABI.empty()) &&
468          "Invalid Floating Point ABI!");
469   Options.FloatABIType =
470       llvm::StringSwitch<llvm::FloatABI::ABIType>(CodeGenOpts.FloatABI)
471           .Case("soft", llvm::FloatABI::Soft)
472           .Case("softfp", llvm::FloatABI::Soft)
473           .Case("hard", llvm::FloatABI::Hard)
474           .Default(llvm::FloatABI::Default);
475 
476   // Set FP fusion mode.
477   switch (LangOpts.getDefaultFPContractMode()) {
478   case LangOptions::FPM_Off:
479     // Preserve any contraction performed by the front-end.  (Strict performs
480     // splitting of the muladd intrinsic in the backend.)
481     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
482     break;
483   case LangOptions::FPM_On:
484   case LangOptions::FPM_FastHonorPragmas:
485     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
486     break;
487   case LangOptions::FPM_Fast:
488     Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
489     break;
490   }
491 
492   Options.UseInitArray = CodeGenOpts.UseInitArray;
493   Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
494   Options.CompressDebugSections = CodeGenOpts.getCompressDebugSections();
495   Options.RelaxELFRelocations = CodeGenOpts.RelaxELFRelocations;
496 
497   // Set EABI version.
498   Options.EABIVersion = TargetOpts.EABIVersion;
499 
500   if (LangOpts.SjLjExceptions)
501     Options.ExceptionModel = llvm::ExceptionHandling::SjLj;
502   if (LangOpts.SEHExceptions)
503     Options.ExceptionModel = llvm::ExceptionHandling::WinEH;
504   if (LangOpts.DWARFExceptions)
505     Options.ExceptionModel = llvm::ExceptionHandling::DwarfCFI;
506   if (LangOpts.WasmExceptions)
507     Options.ExceptionModel = llvm::ExceptionHandling::Wasm;
508 
509   Options.NoInfsFPMath = LangOpts.NoHonorInfs;
510   Options.NoNaNsFPMath = LangOpts.NoHonorNaNs;
511   Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
512   Options.UnsafeFPMath = LangOpts.UnsafeFPMath;
513   Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
514 
515   Options.BBSections =
516       llvm::StringSwitch<llvm::BasicBlockSection>(CodeGenOpts.BBSections)
517           .Case("all", llvm::BasicBlockSection::All)
518           .Case("labels", llvm::BasicBlockSection::Labels)
519           .StartsWith("list=", llvm::BasicBlockSection::List)
520           .Case("none", llvm::BasicBlockSection::None)
521           .Default(llvm::BasicBlockSection::None);
522 
523   if (Options.BBSections == llvm::BasicBlockSection::List) {
524     ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
525         MemoryBuffer::getFile(CodeGenOpts.BBSections.substr(5));
526     if (!MBOrErr) {
527       Diags.Report(diag::err_fe_unable_to_load_basic_block_sections_file)
528           << MBOrErr.getError().message();
529       return false;
530     }
531     Options.BBSectionsFuncListBuf = std::move(*MBOrErr);
532   }
533 
534   Options.EnableMachineFunctionSplitter = CodeGenOpts.SplitMachineFunctions;
535   Options.FunctionSections = CodeGenOpts.FunctionSections;
536   Options.DataSections = CodeGenOpts.DataSections;
537   Options.IgnoreXCOFFVisibility = CodeGenOpts.IgnoreXCOFFVisibility;
538   Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
539   Options.UniqueBasicBlockSectionNames =
540       CodeGenOpts.UniqueBasicBlockSectionNames;
541   Options.StackProtectorGuard =
542       llvm::StringSwitch<llvm::StackProtectorGuards>(CodeGenOpts
543           .StackProtectorGuard)
544           .Case("tls", llvm::StackProtectorGuards::TLS)
545           .Case("global", llvm::StackProtectorGuards::Global)
546           .Default(llvm::StackProtectorGuards::None);
547   Options.StackProtectorGuardOffset = CodeGenOpts.StackProtectorGuardOffset;
548   Options.StackProtectorGuardReg = CodeGenOpts.StackProtectorGuardReg;
549   Options.TLSSize = CodeGenOpts.TLSSize;
550   Options.EmulatedTLS = CodeGenOpts.EmulatedTLS;
551   Options.ExplicitEmulatedTLS = CodeGenOpts.ExplicitEmulatedTLS;
552   Options.DebuggerTuning = CodeGenOpts.getDebuggerTuning();
553   Options.EmitStackSizeSection = CodeGenOpts.StackSizeSection;
554   Options.EmitAddrsig = CodeGenOpts.Addrsig;
555   Options.ForceDwarfFrameSection = CodeGenOpts.ForceDwarfFrameSection;
556   Options.EmitCallSiteInfo = CodeGenOpts.EmitCallSiteInfo;
557   Options.EnableAIXExtendedAltivecABI = CodeGenOpts.EnableAIXExtendedAltivecABI;
558   Options.ValueTrackingVariableLocations =
559       CodeGenOpts.ValueTrackingVariableLocations;
560   Options.XRayOmitFunctionIndex = CodeGenOpts.XRayOmitFunctionIndex;
561 
562   Options.MCOptions.SplitDwarfFile = CodeGenOpts.SplitDwarfFile;
563   Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
564   Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
565   Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
566   Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
567   Options.MCOptions.MCIncrementalLinkerCompatible =
568       CodeGenOpts.IncrementalLinkerCompatible;
569   Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
570   Options.MCOptions.MCNoWarn = CodeGenOpts.NoWarn;
571   Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
572   Options.MCOptions.PreserveAsmComments = CodeGenOpts.PreserveAsmComments;
573   Options.MCOptions.ABIName = TargetOpts.ABI;
574   for (const auto &Entry : HSOpts.UserEntries)
575     if (!Entry.IsFramework &&
576         (Entry.Group == frontend::IncludeDirGroup::Quoted ||
577          Entry.Group == frontend::IncludeDirGroup::Angled ||
578          Entry.Group == frontend::IncludeDirGroup::System))
579       Options.MCOptions.IASSearchPaths.push_back(
580           Entry.IgnoreSysRoot ? Entry.Path : HSOpts.Sysroot + Entry.Path);
581   Options.MCOptions.Argv0 = CodeGenOpts.Argv0;
582   Options.MCOptions.CommandLineArgs = CodeGenOpts.CommandLineArgs;
583 
584   return true;
585 }
586 
587 static Optional<GCOVOptions> getGCOVOptions(const CodeGenOptions &CodeGenOpts,
588                                             const LangOptions &LangOpts) {
589   if (!CodeGenOpts.EmitGcovArcs && !CodeGenOpts.EmitGcovNotes)
590     return None;
591   // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
592   // LLVM's -default-gcov-version flag is set to something invalid.
593   GCOVOptions Options;
594   Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
595   Options.EmitData = CodeGenOpts.EmitGcovArcs;
596   llvm::copy(CodeGenOpts.CoverageVersion, std::begin(Options.Version));
597   Options.NoRedZone = CodeGenOpts.DisableRedZone;
598   Options.Filter = CodeGenOpts.ProfileFilterFiles;
599   Options.Exclude = CodeGenOpts.ProfileExcludeFiles;
600   Options.Atomic = CodeGenOpts.AtomicProfileUpdate;
601   return Options;
602 }
603 
604 static Optional<InstrProfOptions>
605 getInstrProfOptions(const CodeGenOptions &CodeGenOpts,
606                     const LangOptions &LangOpts) {
607   if (!CodeGenOpts.hasProfileClangInstr())
608     return None;
609   InstrProfOptions Options;
610   Options.NoRedZone = CodeGenOpts.DisableRedZone;
611   Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
612   Options.Atomic = CodeGenOpts.AtomicProfileUpdate;
613   return Options;
614 }
615 
616 void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
617                                       legacy::FunctionPassManager &FPM) {
618   // Handle disabling of all LLVM passes, where we want to preserve the
619   // internal module before any optimization.
620   if (CodeGenOpts.DisableLLVMPasses)
621     return;
622 
623   // Figure out TargetLibraryInfo.  This needs to be added to MPM and FPM
624   // manually (and not via PMBuilder), since some passes (eg. InstrProfiling)
625   // are inserted before PMBuilder ones - they'd get the default-constructed
626   // TLI with an unknown target otherwise.
627   Triple TargetTriple(TheModule->getTargetTriple());
628   std::unique_ptr<TargetLibraryInfoImpl> TLII(
629       createTLII(TargetTriple, CodeGenOpts));
630 
631   // If we reached here with a non-empty index file name, then the index file
632   // was empty and we are not performing ThinLTO backend compilation (used in
633   // testing in a distributed build environment). Drop any the type test
634   // assume sequences inserted for whole program vtables so that codegen doesn't
635   // complain.
636   if (!CodeGenOpts.ThinLTOIndexFile.empty())
637     MPM.add(createLowerTypeTestsPass(/*ExportSummary=*/nullptr,
638                                      /*ImportSummary=*/nullptr,
639                                      /*DropTypeTests=*/true));
640 
641   PassManagerBuilderWrapper PMBuilder(TargetTriple, CodeGenOpts, LangOpts);
642 
643   // At O0 and O1 we only run the always inliner which is more efficient. At
644   // higher optimization levels we run the normal inliner.
645   if (CodeGenOpts.OptimizationLevel <= 1) {
646     bool InsertLifetimeIntrinsics = ((CodeGenOpts.OptimizationLevel != 0 &&
647                                       !CodeGenOpts.DisableLifetimeMarkers) ||
648                                      LangOpts.Coroutines);
649     PMBuilder.Inliner = createAlwaysInlinerLegacyPass(InsertLifetimeIntrinsics);
650   } else {
651     // We do not want to inline hot callsites for SamplePGO module-summary build
652     // because profile annotation will happen again in ThinLTO backend, and we
653     // want the IR of the hot path to match the profile.
654     PMBuilder.Inliner = createFunctionInliningPass(
655         CodeGenOpts.OptimizationLevel, CodeGenOpts.OptimizeSize,
656         (!CodeGenOpts.SampleProfileFile.empty() &&
657          CodeGenOpts.PrepareForThinLTO));
658   }
659 
660   PMBuilder.OptLevel = CodeGenOpts.OptimizationLevel;
661   PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
662   PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
663   PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
664   // Only enable CGProfilePass when using integrated assembler, since
665   // non-integrated assemblers don't recognize .cgprofile section.
666   PMBuilder.CallGraphProfile = !CodeGenOpts.DisableIntegratedAS;
667 
668   PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
669   // Loop interleaving in the loop vectorizer has historically been set to be
670   // enabled when loop unrolling is enabled.
671   PMBuilder.LoopsInterleaved = CodeGenOpts.UnrollLoops;
672   PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
673   PMBuilder.PrepareForThinLTO = CodeGenOpts.PrepareForThinLTO;
674   PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
675   PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
676 
677   MPM.add(new TargetLibraryInfoWrapperPass(*TLII));
678 
679   if (TM)
680     TM->adjustPassManager(PMBuilder);
681 
682   if (CodeGenOpts.DebugInfoForProfiling ||
683       !CodeGenOpts.SampleProfileFile.empty())
684     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
685                            addAddDiscriminatorsPass);
686 
687   // In ObjC ARC mode, add the main ARC optimization passes.
688   if (LangOpts.ObjCAutoRefCount) {
689     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
690                            addObjCARCExpandPass);
691     PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
692                            addObjCARCAPElimPass);
693     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
694                            addObjCARCOptPass);
695   }
696 
697   if (LangOpts.Coroutines)
698     addCoroutinePassesToExtensionPoints(PMBuilder);
699 
700   if (!CodeGenOpts.MemoryProfileOutput.empty()) {
701     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
702                            addMemProfilerPasses);
703     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
704                            addMemProfilerPasses);
705   }
706 
707   if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds)) {
708     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
709                            addBoundsCheckingPass);
710     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
711                            addBoundsCheckingPass);
712   }
713 
714   if (CodeGenOpts.SanitizeCoverageType ||
715       CodeGenOpts.SanitizeCoverageIndirectCalls ||
716       CodeGenOpts.SanitizeCoverageTraceCmp) {
717     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
718                            addSanitizerCoveragePass);
719     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
720                            addSanitizerCoveragePass);
721   }
722 
723   if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
724     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
725                            addAddressSanitizerPasses);
726     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
727                            addAddressSanitizerPasses);
728   }
729 
730   if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
731     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
732                            addKernelAddressSanitizerPasses);
733     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
734                            addKernelAddressSanitizerPasses);
735   }
736 
737   if (LangOpts.Sanitize.has(SanitizerKind::HWAddress)) {
738     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
739                            addHWAddressSanitizerPasses);
740     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
741                            addHWAddressSanitizerPasses);
742   }
743 
744   if (LangOpts.Sanitize.has(SanitizerKind::KernelHWAddress)) {
745     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
746                            addKernelHWAddressSanitizerPasses);
747     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
748                            addKernelHWAddressSanitizerPasses);
749   }
750 
751   if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
752     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
753                            addMemorySanitizerPass);
754     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
755                            addMemorySanitizerPass);
756   }
757 
758   if (LangOpts.Sanitize.has(SanitizerKind::KernelMemory)) {
759     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
760                            addKernelMemorySanitizerPass);
761     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
762                            addKernelMemorySanitizerPass);
763   }
764 
765   if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
766     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
767                            addThreadSanitizerPass);
768     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
769                            addThreadSanitizerPass);
770   }
771 
772   if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
773     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
774                            addDataFlowSanitizerPass);
775     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
776                            addDataFlowSanitizerPass);
777   }
778 
779   // Set up the per-function pass manager.
780   FPM.add(new TargetLibraryInfoWrapperPass(*TLII));
781   if (CodeGenOpts.VerifyModule)
782     FPM.add(createVerifierPass());
783 
784   // Set up the per-module pass manager.
785   if (!CodeGenOpts.RewriteMapFiles.empty())
786     addSymbolRewriterPass(CodeGenOpts, &MPM);
787 
788   // Add UniqueInternalLinkageNames Pass which renames internal linkage symbols
789   // with unique names.
790   if (CodeGenOpts.UniqueInternalLinkageNames) {
791     MPM.add(createUniqueInternalLinkageNamesPass());
792   }
793 
794   if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts, LangOpts)) {
795     MPM.add(createGCOVProfilerPass(*Options));
796     if (CodeGenOpts.getDebugInfo() == codegenoptions::NoDebugInfo)
797       MPM.add(createStripSymbolsPass(true));
798   }
799 
800   if (Optional<InstrProfOptions> Options =
801           getInstrProfOptions(CodeGenOpts, LangOpts))
802     MPM.add(createInstrProfilingLegacyPass(*Options, false));
803 
804   bool hasIRInstr = false;
805   if (CodeGenOpts.hasProfileIRInstr()) {
806     PMBuilder.EnablePGOInstrGen = true;
807     hasIRInstr = true;
808   }
809   if (CodeGenOpts.hasProfileCSIRInstr()) {
810     assert(!CodeGenOpts.hasProfileCSIRUse() &&
811            "Cannot have both CSProfileUse pass and CSProfileGen pass at the "
812            "same time");
813     assert(!hasIRInstr &&
814            "Cannot have both ProfileGen pass and CSProfileGen pass at the "
815            "same time");
816     PMBuilder.EnablePGOCSInstrGen = true;
817     hasIRInstr = true;
818   }
819   if (hasIRInstr) {
820     if (!CodeGenOpts.InstrProfileOutput.empty())
821       PMBuilder.PGOInstrGen = CodeGenOpts.InstrProfileOutput;
822     else
823       PMBuilder.PGOInstrGen = std::string(DefaultProfileGenName);
824   }
825   if (CodeGenOpts.hasProfileIRUse()) {
826     PMBuilder.PGOInstrUse = CodeGenOpts.ProfileInstrumentUsePath;
827     PMBuilder.EnablePGOCSInstrUse = CodeGenOpts.hasProfileCSIRUse();
828   }
829 
830   if (!CodeGenOpts.SampleProfileFile.empty())
831     PMBuilder.PGOSampleUse = CodeGenOpts.SampleProfileFile;
832 
833   PMBuilder.populateFunctionPassManager(FPM);
834   PMBuilder.populateModulePassManager(MPM);
835 }
836 
837 static void setCommandLineOpts(const CodeGenOptions &CodeGenOpts) {
838   SmallVector<const char *, 16> BackendArgs;
839   BackendArgs.push_back("clang"); // Fake program name.
840   if (!CodeGenOpts.DebugPass.empty()) {
841     BackendArgs.push_back("-debug-pass");
842     BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
843   }
844   if (!CodeGenOpts.LimitFloatPrecision.empty()) {
845     BackendArgs.push_back("-limit-float-precision");
846     BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
847   }
848   BackendArgs.push_back(nullptr);
849   llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
850                                     BackendArgs.data());
851 }
852 
853 void EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
854   // Create the TargetMachine for generating code.
855   std::string Error;
856   std::string Triple = TheModule->getTargetTriple();
857   const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
858   if (!TheTarget) {
859     if (MustCreateTM)
860       Diags.Report(diag::err_fe_unable_to_create_target) << Error;
861     return;
862   }
863 
864   Optional<llvm::CodeModel::Model> CM = getCodeModel(CodeGenOpts);
865   std::string FeaturesStr =
866       llvm::join(TargetOpts.Features.begin(), TargetOpts.Features.end(), ",");
867   llvm::Reloc::Model RM = CodeGenOpts.RelocationModel;
868   CodeGenOpt::Level OptLevel = getCGOptLevel(CodeGenOpts);
869 
870   llvm::TargetOptions Options;
871   if (!initTargetOptions(Diags, Options, CodeGenOpts, TargetOpts, LangOpts,
872                          HSOpts))
873     return;
874   TM.reset(TheTarget->createTargetMachine(Triple, TargetOpts.CPU, FeaturesStr,
875                                           Options, RM, CM, OptLevel));
876 }
877 
878 bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
879                                        BackendAction Action,
880                                        raw_pwrite_stream &OS,
881                                        raw_pwrite_stream *DwoOS) {
882   // Add LibraryInfo.
883   llvm::Triple TargetTriple(TheModule->getTargetTriple());
884   std::unique_ptr<TargetLibraryInfoImpl> TLII(
885       createTLII(TargetTriple, CodeGenOpts));
886   CodeGenPasses.add(new TargetLibraryInfoWrapperPass(*TLII));
887 
888   // Normal mode, emit a .s or .o file by running the code generator. Note,
889   // this also adds codegenerator level optimization passes.
890   CodeGenFileType CGFT = getCodeGenFileType(Action);
891 
892   // Add ObjC ARC final-cleanup optimizations. This is done as part of the
893   // "codegen" passes so that it isn't run multiple times when there is
894   // inlining happening.
895   if (CodeGenOpts.OptimizationLevel > 0)
896     CodeGenPasses.add(createObjCARCContractPass());
897 
898   if (TM->addPassesToEmitFile(CodeGenPasses, OS, DwoOS, CGFT,
899                               /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
900     Diags.Report(diag::err_fe_unable_to_interface_with_target);
901     return false;
902   }
903 
904   return true;
905 }
906 
907 void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
908                                       std::unique_ptr<raw_pwrite_stream> OS) {
909   TimeRegion Region(FrontendTimesIsEnabled ? &CodeGenerationTime : nullptr);
910 
911   setCommandLineOpts(CodeGenOpts);
912 
913   bool UsesCodeGen = (Action != Backend_EmitNothing &&
914                       Action != Backend_EmitBC &&
915                       Action != Backend_EmitLL);
916   CreateTargetMachine(UsesCodeGen);
917 
918   if (UsesCodeGen && !TM)
919     return;
920   if (TM)
921     TheModule->setDataLayout(TM->createDataLayout());
922 
923   legacy::PassManager PerModulePasses;
924   PerModulePasses.add(
925       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
926 
927   legacy::FunctionPassManager PerFunctionPasses(TheModule);
928   PerFunctionPasses.add(
929       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
930 
931   CreatePasses(PerModulePasses, PerFunctionPasses);
932 
933   legacy::PassManager CodeGenPasses;
934   CodeGenPasses.add(
935       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
936 
937   std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
938 
939   switch (Action) {
940   case Backend_EmitNothing:
941     break;
942 
943   case Backend_EmitBC:
944     if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
945       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
946         ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
947         if (!ThinLinkOS)
948           return;
949       }
950       TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
951                                CodeGenOpts.EnableSplitLTOUnit);
952       PerModulePasses.add(createWriteThinLTOBitcodePass(
953           *OS, ThinLinkOS ? &ThinLinkOS->os() : nullptr));
954     } else {
955       // Emit a module summary by default for Regular LTO except for ld64
956       // targets
957       bool EmitLTOSummary =
958           (CodeGenOpts.PrepareForLTO &&
959            !CodeGenOpts.DisableLLVMPasses &&
960            llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
961                llvm::Triple::Apple);
962       if (EmitLTOSummary) {
963         if (!TheModule->getModuleFlag("ThinLTO"))
964           TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
965         TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
966                                  uint32_t(1));
967       }
968 
969       PerModulePasses.add(createBitcodeWriterPass(
970           *OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
971     }
972     break;
973 
974   case Backend_EmitLL:
975     PerModulePasses.add(
976         createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
977     break;
978 
979   default:
980     if (!CodeGenOpts.SplitDwarfOutput.empty()) {
981       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
982       if (!DwoOS)
983         return;
984     }
985     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
986                        DwoOS ? &DwoOS->os() : nullptr))
987       return;
988   }
989 
990   // Before executing passes, print the final values of the LLVM options.
991   cl::PrintOptionValues();
992 
993   // Run passes. For now we do all passes at once, but eventually we
994   // would like to have the option of streaming code generation.
995 
996   {
997     PrettyStackTraceString CrashInfo("Per-function optimization");
998     llvm::TimeTraceScope TimeScope("PerFunctionPasses");
999 
1000     PerFunctionPasses.doInitialization();
1001     for (Function &F : *TheModule)
1002       if (!F.isDeclaration())
1003         PerFunctionPasses.run(F);
1004     PerFunctionPasses.doFinalization();
1005   }
1006 
1007   {
1008     PrettyStackTraceString CrashInfo("Per-module optimization passes");
1009     llvm::TimeTraceScope TimeScope("PerModulePasses");
1010     PerModulePasses.run(*TheModule);
1011   }
1012 
1013   {
1014     PrettyStackTraceString CrashInfo("Code generation");
1015     llvm::TimeTraceScope TimeScope("CodeGenPasses");
1016     CodeGenPasses.run(*TheModule);
1017   }
1018 
1019   if (ThinLinkOS)
1020     ThinLinkOS->keep();
1021   if (DwoOS)
1022     DwoOS->keep();
1023 }
1024 
1025 static PassBuilder::OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
1026   switch (Opts.OptimizationLevel) {
1027   default:
1028     llvm_unreachable("Invalid optimization level!");
1029 
1030   case 0:
1031     return PassBuilder::OptimizationLevel::O0;
1032 
1033   case 1:
1034     return PassBuilder::OptimizationLevel::O1;
1035 
1036   case 2:
1037     switch (Opts.OptimizeSize) {
1038     default:
1039       llvm_unreachable("Invalid optimization level for size!");
1040 
1041     case 0:
1042       return PassBuilder::OptimizationLevel::O2;
1043 
1044     case 1:
1045       return PassBuilder::OptimizationLevel::Os;
1046 
1047     case 2:
1048       return PassBuilder::OptimizationLevel::Oz;
1049     }
1050 
1051   case 3:
1052     return PassBuilder::OptimizationLevel::O3;
1053   }
1054 }
1055 
1056 /// A clean version of `EmitAssembly` that uses the new pass manager.
1057 ///
1058 /// Not all features are currently supported in this system, but where
1059 /// necessary it falls back to the legacy pass manager to at least provide
1060 /// basic functionality.
1061 ///
1062 /// This API is planned to have its functionality finished and then to replace
1063 /// `EmitAssembly` at some point in the future when the default switches.
1064 void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
1065     BackendAction Action, std::unique_ptr<raw_pwrite_stream> OS) {
1066   TimeRegion Region(FrontendTimesIsEnabled ? &CodeGenerationTime : nullptr);
1067   setCommandLineOpts(CodeGenOpts);
1068 
1069   bool RequiresCodeGen = (Action != Backend_EmitNothing &&
1070                           Action != Backend_EmitBC &&
1071                           Action != Backend_EmitLL);
1072   CreateTargetMachine(RequiresCodeGen);
1073 
1074   if (RequiresCodeGen && !TM)
1075     return;
1076   if (TM)
1077     TheModule->setDataLayout(TM->createDataLayout());
1078 
1079   Optional<PGOOptions> PGOOpt;
1080 
1081   if (CodeGenOpts.hasProfileIRInstr())
1082     // -fprofile-generate.
1083     PGOOpt = PGOOptions(CodeGenOpts.InstrProfileOutput.empty()
1084                             ? std::string(DefaultProfileGenName)
1085                             : CodeGenOpts.InstrProfileOutput,
1086                         "", "", PGOOptions::IRInstr, PGOOptions::NoCSAction,
1087                         CodeGenOpts.DebugInfoForProfiling);
1088   else if (CodeGenOpts.hasProfileIRUse()) {
1089     // -fprofile-use.
1090     auto CSAction = CodeGenOpts.hasProfileCSIRUse() ? PGOOptions::CSIRUse
1091                                                     : PGOOptions::NoCSAction;
1092     PGOOpt = PGOOptions(CodeGenOpts.ProfileInstrumentUsePath, "",
1093                         CodeGenOpts.ProfileRemappingFile, PGOOptions::IRUse,
1094                         CSAction, CodeGenOpts.DebugInfoForProfiling);
1095   } else if (!CodeGenOpts.SampleProfileFile.empty())
1096     // -fprofile-sample-use
1097     PGOOpt =
1098         PGOOptions(CodeGenOpts.SampleProfileFile, "",
1099                    CodeGenOpts.ProfileRemappingFile, PGOOptions::SampleUse,
1100                    PGOOptions::NoCSAction, CodeGenOpts.DebugInfoForProfiling);
1101   else if (CodeGenOpts.DebugInfoForProfiling)
1102     // -fdebug-info-for-profiling
1103     PGOOpt = PGOOptions("", "", "", PGOOptions::NoAction,
1104                         PGOOptions::NoCSAction, true);
1105 
1106   // Check to see if we want to generate a CS profile.
1107   if (CodeGenOpts.hasProfileCSIRInstr()) {
1108     assert(!CodeGenOpts.hasProfileCSIRUse() &&
1109            "Cannot have both CSProfileUse pass and CSProfileGen pass at "
1110            "the same time");
1111     if (PGOOpt.hasValue()) {
1112       assert(PGOOpt->Action != PGOOptions::IRInstr &&
1113              PGOOpt->Action != PGOOptions::SampleUse &&
1114              "Cannot run CSProfileGen pass with ProfileGen or SampleUse "
1115              " pass");
1116       PGOOpt->CSProfileGenFile = CodeGenOpts.InstrProfileOutput.empty()
1117                                      ? std::string(DefaultProfileGenName)
1118                                      : CodeGenOpts.InstrProfileOutput;
1119       PGOOpt->CSAction = PGOOptions::CSIRInstr;
1120     } else
1121       PGOOpt = PGOOptions("",
1122                           CodeGenOpts.InstrProfileOutput.empty()
1123                               ? std::string(DefaultProfileGenName)
1124                               : CodeGenOpts.InstrProfileOutput,
1125                           "", PGOOptions::NoAction, PGOOptions::CSIRInstr,
1126                           CodeGenOpts.DebugInfoForProfiling);
1127   }
1128 
1129   PipelineTuningOptions PTO;
1130   PTO.LoopUnrolling = CodeGenOpts.UnrollLoops;
1131   // For historical reasons, loop interleaving is set to mirror setting for loop
1132   // unrolling.
1133   PTO.LoopInterleaving = CodeGenOpts.UnrollLoops;
1134   PTO.LoopVectorization = CodeGenOpts.VectorizeLoop;
1135   PTO.SLPVectorization = CodeGenOpts.VectorizeSLP;
1136   // Only enable CGProfilePass when using integrated assembler, since
1137   // non-integrated assemblers don't recognize .cgprofile section.
1138   PTO.CallGraphProfile = !CodeGenOpts.DisableIntegratedAS;
1139   PTO.Coroutines = LangOpts.Coroutines;
1140 
1141   PassInstrumentationCallbacks PIC;
1142   StandardInstrumentations SI(CodeGenOpts.DebugPassManager);
1143   SI.registerCallbacks(PIC);
1144   PassBuilder PB(CodeGenOpts.DebugPassManager, TM.get(), PTO, PGOOpt, &PIC);
1145 
1146   // Attempt to load pass plugins and register their callbacks with PB.
1147   for (auto &PluginFN : CodeGenOpts.PassPlugins) {
1148     auto PassPlugin = PassPlugin::Load(PluginFN);
1149     if (PassPlugin) {
1150       PassPlugin->registerPassBuilderCallbacks(PB);
1151     } else {
1152       Diags.Report(diag::err_fe_unable_to_load_plugin)
1153           << PluginFN << toString(PassPlugin.takeError());
1154     }
1155   }
1156 #define HANDLE_EXTENSION(Ext)                                                  \
1157   get##Ext##PluginInfo().RegisterPassBuilderCallbacks(PB);
1158 #include "llvm/Support/Extension.def"
1159 
1160   LoopAnalysisManager LAM(CodeGenOpts.DebugPassManager);
1161   FunctionAnalysisManager FAM(CodeGenOpts.DebugPassManager);
1162   CGSCCAnalysisManager CGAM(CodeGenOpts.DebugPassManager);
1163   ModuleAnalysisManager MAM(CodeGenOpts.DebugPassManager);
1164 
1165   // Register the AA manager first so that our version is the one used.
1166   FAM.registerPass([&] { return PB.buildDefaultAAPipeline(); });
1167 
1168   // Register the target library analysis directly and give it a customized
1169   // preset TLI.
1170   Triple TargetTriple(TheModule->getTargetTriple());
1171   std::unique_ptr<TargetLibraryInfoImpl> TLII(
1172       createTLII(TargetTriple, CodeGenOpts));
1173   FAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); });
1174 
1175   // Register all the basic analyses with the managers.
1176   PB.registerModuleAnalyses(MAM);
1177   PB.registerCGSCCAnalyses(CGAM);
1178   PB.registerFunctionAnalyses(FAM);
1179   PB.registerLoopAnalyses(LAM);
1180   PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
1181 
1182   ModulePassManager MPM(CodeGenOpts.DebugPassManager);
1183 
1184   if (!CodeGenOpts.DisableLLVMPasses) {
1185     // Map our optimization levels into one of the distinct levels used to
1186     // configure the pipeline.
1187     PassBuilder::OptimizationLevel Level = mapToLevel(CodeGenOpts);
1188 
1189     bool IsThinLTO = CodeGenOpts.PrepareForThinLTO;
1190     bool IsLTO = CodeGenOpts.PrepareForLTO;
1191 
1192     // If we reached here with a non-empty index file name, then the index
1193     // file was empty and we are not performing ThinLTO backend compilation
1194     // (used in testing in a distributed build environment). Drop any the type
1195     // test assume sequences inserted for whole program vtables so that
1196     // codegen doesn't complain.
1197     if (!CodeGenOpts.ThinLTOIndexFile.empty())
1198       PB.registerPipelineStartEPCallback(
1199           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1200             MPM.addPass(LowerTypeTestsPass(/*ExportSummary=*/nullptr,
1201                                            /*ImportSummary=*/nullptr,
1202                                            /*DropTypeTests=*/true));
1203           });
1204 
1205     if (Level != PassBuilder::OptimizationLevel::O0) {
1206       PB.registerPipelineStartEPCallback(
1207           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1208             MPM.addPass(createModuleToFunctionPassAdaptor(
1209                 EntryExitInstrumenterPass(/*PostInlining=*/false)));
1210           });
1211     }
1212 
1213     // Register callbacks to schedule sanitizer passes at the appropriate part
1214     // of the pipeline.
1215     if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
1216       PB.registerScalarOptimizerLateEPCallback(
1217           [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
1218             FPM.addPass(BoundsCheckingPass());
1219           });
1220 
1221     if (CodeGenOpts.SanitizeCoverageType ||
1222         CodeGenOpts.SanitizeCoverageIndirectCalls ||
1223         CodeGenOpts.SanitizeCoverageTraceCmp) {
1224       PB.registerOptimizerLastEPCallback(
1225           [this](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1226             auto SancovOpts = getSancovOptsFromCGOpts(CodeGenOpts);
1227             MPM.addPass(ModuleSanitizerCoveragePass(
1228                 SancovOpts, CodeGenOpts.SanitizeCoverageAllowlistFiles,
1229                 CodeGenOpts.SanitizeCoverageBlocklistFiles));
1230           });
1231     }
1232 
1233     if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
1234       int TrackOrigins = CodeGenOpts.SanitizeMemoryTrackOrigins;
1235       bool Recover = CodeGenOpts.SanitizeRecover.has(SanitizerKind::Memory);
1236       PB.registerOptimizerLastEPCallback(
1237           [TrackOrigins, Recover](ModulePassManager &MPM,
1238                                   PassBuilder::OptimizationLevel Level) {
1239             MPM.addPass(MemorySanitizerPass({TrackOrigins, Recover, false}));
1240             MPM.addPass(createModuleToFunctionPassAdaptor(
1241                 MemorySanitizerPass({TrackOrigins, Recover, false})));
1242           });
1243     }
1244     if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
1245       PB.registerOptimizerLastEPCallback(
1246           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1247             MPM.addPass(ThreadSanitizerPass());
1248             MPM.addPass(
1249                 createModuleToFunctionPassAdaptor(ThreadSanitizerPass()));
1250           });
1251     }
1252 
1253     auto ASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
1254       if (LangOpts.Sanitize.has(Mask)) {
1255         bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
1256         bool UseAfterScope = CodeGenOpts.SanitizeAddressUseAfterScope;
1257         bool ModuleUseAfterScope = asanUseGlobalsGC(TargetTriple, CodeGenOpts);
1258         bool UseOdrIndicator = CodeGenOpts.SanitizeAddressUseOdrIndicator;
1259         PB.registerOptimizerLastEPCallback(
1260             [CompileKernel, Recover, UseAfterScope, ModuleUseAfterScope,
1261              UseOdrIndicator](ModulePassManager &MPM,
1262                               PassBuilder::OptimizationLevel Level) {
1263               MPM.addPass(
1264                   RequireAnalysisPass<ASanGlobalsMetadataAnalysis, Module>());
1265               MPM.addPass(ModuleAddressSanitizerPass(CompileKernel, Recover,
1266                                                      ModuleUseAfterScope,
1267                                                      UseOdrIndicator));
1268               MPM.addPass(createModuleToFunctionPassAdaptor(
1269                   AddressSanitizerPass(CompileKernel, Recover, UseAfterScope)));
1270             });
1271       }
1272     };
1273     ASanPass(SanitizerKind::Address, false);
1274     ASanPass(SanitizerKind::KernelAddress, true);
1275 
1276     auto HWASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
1277       if (LangOpts.Sanitize.has(Mask)) {
1278         bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
1279         PB.registerOptimizerLastEPCallback(
1280             [CompileKernel, Recover](ModulePassManager &MPM,
1281                                      PassBuilder::OptimizationLevel Level) {
1282               MPM.addPass(HWAddressSanitizerPass(CompileKernel, Recover));
1283             });
1284       }
1285     };
1286     HWASanPass(SanitizerKind::HWAddress, false);
1287     HWASanPass(SanitizerKind::KernelHWAddress, true);
1288 
1289     if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
1290       PB.registerOptimizerLastEPCallback(
1291           [this](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1292             MPM.addPass(
1293                 DataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
1294           });
1295     }
1296 
1297     if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts, LangOpts))
1298       PB.registerPipelineStartEPCallback(
1299           [Options](ModulePassManager &MPM,
1300                     PassBuilder::OptimizationLevel Level) {
1301             MPM.addPass(GCOVProfilerPass(*Options));
1302           });
1303     if (Optional<InstrProfOptions> Options =
1304             getInstrProfOptions(CodeGenOpts, LangOpts))
1305       PB.registerPipelineStartEPCallback(
1306           [Options](ModulePassManager &MPM,
1307                     PassBuilder::OptimizationLevel Level) {
1308             MPM.addPass(InstrProfiling(*Options, false));
1309           });
1310 
1311     if (CodeGenOpts.OptimizationLevel == 0) {
1312       MPM = PB.buildO0DefaultPipeline(Level, IsLTO || IsThinLTO);
1313     } else if (IsThinLTO) {
1314       MPM = PB.buildThinLTOPreLinkDefaultPipeline(Level);
1315     } else if (IsLTO) {
1316       MPM = PB.buildLTOPreLinkDefaultPipeline(Level);
1317     } else {
1318       MPM = PB.buildPerModuleDefaultPipeline(Level);
1319     }
1320 
1321     // Add UniqueInternalLinkageNames Pass which renames internal linkage
1322     // symbols with unique names.
1323     if (CodeGenOpts.UniqueInternalLinkageNames)
1324       MPM.addPass(UniqueInternalLinkageNamesPass());
1325 
1326     if (!CodeGenOpts.MemoryProfileOutput.empty()) {
1327       MPM.addPass(createModuleToFunctionPassAdaptor(MemProfilerPass()));
1328       MPM.addPass(ModuleMemProfilerPass());
1329     }
1330   }
1331 
1332   // FIXME: We still use the legacy pass manager to do code generation. We
1333   // create that pass manager here and use it as needed below.
1334   legacy::PassManager CodeGenPasses;
1335   bool NeedCodeGen = false;
1336   std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
1337 
1338   // Append any output we need to the pass manager.
1339   switch (Action) {
1340   case Backend_EmitNothing:
1341     break;
1342 
1343   case Backend_EmitBC:
1344     if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
1345       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
1346         ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
1347         if (!ThinLinkOS)
1348           return;
1349       }
1350       TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1351                                CodeGenOpts.EnableSplitLTOUnit);
1352       MPM.addPass(ThinLTOBitcodeWriterPass(*OS, ThinLinkOS ? &ThinLinkOS->os()
1353                                                            : nullptr));
1354     } else {
1355       // Emit a module summary by default for Regular LTO except for ld64
1356       // targets
1357       bool EmitLTOSummary =
1358           (CodeGenOpts.PrepareForLTO &&
1359            !CodeGenOpts.DisableLLVMPasses &&
1360            llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
1361                llvm::Triple::Apple);
1362       if (EmitLTOSummary) {
1363         if (!TheModule->getModuleFlag("ThinLTO"))
1364           TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
1365         TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1366                                  uint32_t(1));
1367       }
1368       MPM.addPass(
1369           BitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
1370     }
1371     break;
1372 
1373   case Backend_EmitLL:
1374     MPM.addPass(PrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
1375     break;
1376 
1377   case Backend_EmitAssembly:
1378   case Backend_EmitMCNull:
1379   case Backend_EmitObj:
1380     NeedCodeGen = true;
1381     CodeGenPasses.add(
1382         createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
1383     if (!CodeGenOpts.SplitDwarfOutput.empty()) {
1384       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
1385       if (!DwoOS)
1386         return;
1387     }
1388     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
1389                        DwoOS ? &DwoOS->os() : nullptr))
1390       // FIXME: Should we handle this error differently?
1391       return;
1392     break;
1393   }
1394 
1395   // Before executing passes, print the final values of the LLVM options.
1396   cl::PrintOptionValues();
1397 
1398   // Now that we have all of the passes ready, run them.
1399   {
1400     PrettyStackTraceString CrashInfo("Optimizer");
1401     MPM.run(*TheModule, MAM);
1402   }
1403 
1404   // Now if needed, run the legacy PM for codegen.
1405   if (NeedCodeGen) {
1406     PrettyStackTraceString CrashInfo("Code generation");
1407     CodeGenPasses.run(*TheModule);
1408   }
1409 
1410   if (ThinLinkOS)
1411     ThinLinkOS->keep();
1412   if (DwoOS)
1413     DwoOS->keep();
1414 }
1415 
1416 static void runThinLTOBackend(
1417     DiagnosticsEngine &Diags, ModuleSummaryIndex *CombinedIndex, Module *M,
1418     const HeaderSearchOptions &HeaderOpts, const CodeGenOptions &CGOpts,
1419     const clang::TargetOptions &TOpts, const LangOptions &LOpts,
1420     std::unique_ptr<raw_pwrite_stream> OS, std::string SampleProfile,
1421     std::string ProfileRemapping, BackendAction Action) {
1422   StringMap<DenseMap<GlobalValue::GUID, GlobalValueSummary *>>
1423       ModuleToDefinedGVSummaries;
1424   CombinedIndex->collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries);
1425 
1426   setCommandLineOpts(CGOpts);
1427 
1428   // We can simply import the values mentioned in the combined index, since
1429   // we should only invoke this using the individual indexes written out
1430   // via a WriteIndexesThinBackend.
1431   FunctionImporter::ImportMapTy ImportList;
1432   std::vector<std::unique_ptr<llvm::MemoryBuffer>> OwnedImports;
1433   MapVector<llvm::StringRef, llvm::BitcodeModule> ModuleMap;
1434   if (!lto::loadReferencedModules(*M, *CombinedIndex, ImportList, ModuleMap,
1435                                   OwnedImports))
1436     return;
1437 
1438   auto AddStream = [&](size_t Task) {
1439     return std::make_unique<lto::NativeObjectStream>(std::move(OS));
1440   };
1441   lto::Config Conf;
1442   if (CGOpts.SaveTempsFilePrefix != "") {
1443     if (Error E = Conf.addSaveTemps(CGOpts.SaveTempsFilePrefix + ".",
1444                                     /* UseInputModulePath */ false)) {
1445       handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1446         errs() << "Error setting up ThinLTO save-temps: " << EIB.message()
1447                << '\n';
1448       });
1449     }
1450   }
1451   Conf.CPU = TOpts.CPU;
1452   Conf.CodeModel = getCodeModel(CGOpts);
1453   Conf.MAttrs = TOpts.Features;
1454   Conf.RelocModel = CGOpts.RelocationModel;
1455   Conf.CGOptLevel = getCGOptLevel(CGOpts);
1456   Conf.OptLevel = CGOpts.OptimizationLevel;
1457   initTargetOptions(Diags, Conf.Options, CGOpts, TOpts, LOpts, HeaderOpts);
1458   Conf.SampleProfile = std::move(SampleProfile);
1459   Conf.PTO.LoopUnrolling = CGOpts.UnrollLoops;
1460   // For historical reasons, loop interleaving is set to mirror setting for loop
1461   // unrolling.
1462   Conf.PTO.LoopInterleaving = CGOpts.UnrollLoops;
1463   Conf.PTO.LoopVectorization = CGOpts.VectorizeLoop;
1464   Conf.PTO.SLPVectorization = CGOpts.VectorizeSLP;
1465   // Only enable CGProfilePass when using integrated assembler, since
1466   // non-integrated assemblers don't recognize .cgprofile section.
1467   Conf.PTO.CallGraphProfile = !CGOpts.DisableIntegratedAS;
1468 
1469   // Context sensitive profile.
1470   if (CGOpts.hasProfileCSIRInstr()) {
1471     Conf.RunCSIRInstr = true;
1472     Conf.CSIRProfile = std::move(CGOpts.InstrProfileOutput);
1473   } else if (CGOpts.hasProfileCSIRUse()) {
1474     Conf.RunCSIRInstr = false;
1475     Conf.CSIRProfile = std::move(CGOpts.ProfileInstrumentUsePath);
1476   }
1477 
1478   Conf.ProfileRemapping = std::move(ProfileRemapping);
1479   Conf.UseNewPM = CGOpts.ExperimentalNewPassManager;
1480   Conf.DebugPassManager = CGOpts.DebugPassManager;
1481   Conf.RemarksWithHotness = CGOpts.DiagnosticsWithHotness;
1482   Conf.RemarksFilename = CGOpts.OptRecordFile;
1483   Conf.RemarksPasses = CGOpts.OptRecordPasses;
1484   Conf.RemarksFormat = CGOpts.OptRecordFormat;
1485   Conf.SplitDwarfFile = CGOpts.SplitDwarfFile;
1486   Conf.SplitDwarfOutput = CGOpts.SplitDwarfOutput;
1487   switch (Action) {
1488   case Backend_EmitNothing:
1489     Conf.PreCodeGenModuleHook = [](size_t Task, const Module &Mod) {
1490       return false;
1491     };
1492     break;
1493   case Backend_EmitLL:
1494     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1495       M->print(*OS, nullptr, CGOpts.EmitLLVMUseLists);
1496       return false;
1497     };
1498     break;
1499   case Backend_EmitBC:
1500     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1501       WriteBitcodeToFile(*M, *OS, CGOpts.EmitLLVMUseLists);
1502       return false;
1503     };
1504     break;
1505   default:
1506     Conf.CGFileType = getCodeGenFileType(Action);
1507     break;
1508   }
1509   if (Error E =
1510           thinBackend(Conf, -1, AddStream, *M, *CombinedIndex, ImportList,
1511                       ModuleToDefinedGVSummaries[M->getModuleIdentifier()],
1512                       ModuleMap, CGOpts.CmdArgs)) {
1513     handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1514       errs() << "Error running ThinLTO backend: " << EIB.message() << '\n';
1515     });
1516   }
1517 }
1518 
1519 void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
1520                               const HeaderSearchOptions &HeaderOpts,
1521                               const CodeGenOptions &CGOpts,
1522                               const clang::TargetOptions &TOpts,
1523                               const LangOptions &LOpts,
1524                               const llvm::DataLayout &TDesc, Module *M,
1525                               BackendAction Action,
1526                               std::unique_ptr<raw_pwrite_stream> OS) {
1527 
1528   llvm::TimeTraceScope TimeScope("Backend");
1529 
1530   std::unique_ptr<llvm::Module> EmptyModule;
1531   if (!CGOpts.ThinLTOIndexFile.empty()) {
1532     // If we are performing a ThinLTO importing compile, load the function index
1533     // into memory and pass it into runThinLTOBackend, which will run the
1534     // function importer and invoke LTO passes.
1535     Expected<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
1536         llvm::getModuleSummaryIndexForFile(CGOpts.ThinLTOIndexFile,
1537                                            /*IgnoreEmptyThinLTOIndexFile*/true);
1538     if (!IndexOrErr) {
1539       logAllUnhandledErrors(IndexOrErr.takeError(), errs(),
1540                             "Error loading index file '" +
1541                             CGOpts.ThinLTOIndexFile + "': ");
1542       return;
1543     }
1544     std::unique_ptr<ModuleSummaryIndex> CombinedIndex = std::move(*IndexOrErr);
1545     // A null CombinedIndex means we should skip ThinLTO compilation
1546     // (LLVM will optionally ignore empty index files, returning null instead
1547     // of an error).
1548     if (CombinedIndex) {
1549       if (!CombinedIndex->skipModuleByDistributedBackend()) {
1550         runThinLTOBackend(Diags, CombinedIndex.get(), M, HeaderOpts, CGOpts,
1551                           TOpts, LOpts, std::move(OS), CGOpts.SampleProfileFile,
1552                           CGOpts.ProfileRemappingFile, Action);
1553         return;
1554       }
1555       // Distributed indexing detected that nothing from the module is needed
1556       // for the final linking. So we can skip the compilation. We sill need to
1557       // output an empty object file to make sure that a linker does not fail
1558       // trying to read it. Also for some features, like CFI, we must skip
1559       // the compilation as CombinedIndex does not contain all required
1560       // information.
1561       EmptyModule = std::make_unique<llvm::Module>("empty", M->getContext());
1562       EmptyModule->setTargetTriple(M->getTargetTriple());
1563       M = EmptyModule.get();
1564     }
1565   }
1566 
1567   EmitAssemblyHelper AsmHelper(Diags, HeaderOpts, CGOpts, TOpts, LOpts, M);
1568 
1569   if (CGOpts.ExperimentalNewPassManager)
1570     AsmHelper.EmitAssemblyWithNewPassManager(Action, std::move(OS));
1571   else
1572     AsmHelper.EmitAssembly(Action, std::move(OS));
1573 
1574   // Verify clang's TargetInfo DataLayout against the LLVM TargetMachine's
1575   // DataLayout.
1576   if (AsmHelper.TM) {
1577     std::string DLDesc = M->getDataLayout().getStringRepresentation();
1578     if (DLDesc != TDesc.getStringRepresentation()) {
1579       unsigned DiagID = Diags.getCustomDiagID(
1580           DiagnosticsEngine::Error, "backend data layout '%0' does not match "
1581                                     "expected target description '%1'");
1582       Diags.Report(DiagID) << DLDesc << TDesc.getStringRepresentation();
1583     }
1584   }
1585 }
1586 
1587 // With -fembed-bitcode, save a copy of the llvm IR as data in the
1588 // __LLVM,__bitcode section.
1589 void clang::EmbedBitcode(llvm::Module *M, const CodeGenOptions &CGOpts,
1590                          llvm::MemoryBufferRef Buf) {
1591   if (CGOpts.getEmbedBitcode() == CodeGenOptions::Embed_Off)
1592     return;
1593   llvm::EmbedBitcodeInModule(
1594       *M, Buf, CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Marker,
1595       CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Bitcode,
1596       CGOpts.CmdArgs);
1597 }
1598