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     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
485     break;
486   case LangOptions::FPM_Fast:
487     Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
488     break;
489   }
490 
491   Options.UseInitArray = CodeGenOpts.UseInitArray;
492   Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
493   Options.CompressDebugSections = CodeGenOpts.getCompressDebugSections();
494   Options.RelaxELFRelocations = CodeGenOpts.RelaxELFRelocations;
495 
496   // Set EABI version.
497   Options.EABIVersion = TargetOpts.EABIVersion;
498 
499   if (LangOpts.SjLjExceptions)
500     Options.ExceptionModel = llvm::ExceptionHandling::SjLj;
501   if (LangOpts.SEHExceptions)
502     Options.ExceptionModel = llvm::ExceptionHandling::WinEH;
503   if (LangOpts.DWARFExceptions)
504     Options.ExceptionModel = llvm::ExceptionHandling::DwarfCFI;
505   if (LangOpts.WasmExceptions)
506     Options.ExceptionModel = llvm::ExceptionHandling::Wasm;
507 
508   Options.NoInfsFPMath = LangOpts.NoHonorInfs;
509   Options.NoNaNsFPMath = LangOpts.NoHonorNaNs;
510   Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
511   Options.UnsafeFPMath = LangOpts.UnsafeFPMath;
512   Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
513 
514   Options.BBSections =
515       llvm::StringSwitch<llvm::BasicBlockSection>(CodeGenOpts.BBSections)
516           .Case("all", llvm::BasicBlockSection::All)
517           .Case("labels", llvm::BasicBlockSection::Labels)
518           .StartsWith("list=", llvm::BasicBlockSection::List)
519           .Case("none", llvm::BasicBlockSection::None)
520           .Default(llvm::BasicBlockSection::None);
521 
522   if (Options.BBSections == llvm::BasicBlockSection::List) {
523     ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
524         MemoryBuffer::getFile(CodeGenOpts.BBSections.substr(5));
525     if (!MBOrErr) {
526       Diags.Report(diag::err_fe_unable_to_load_basic_block_sections_file)
527           << MBOrErr.getError().message();
528       return false;
529     }
530     Options.BBSectionsFuncListBuf = std::move(*MBOrErr);
531   }
532 
533   Options.EnableMachineFunctionSplitter = CodeGenOpts.SplitMachineFunctions;
534   Options.FunctionSections = CodeGenOpts.FunctionSections;
535   Options.DataSections = CodeGenOpts.DataSections;
536   Options.IgnoreXCOFFVisibility = CodeGenOpts.IgnoreXCOFFVisibility;
537   Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
538   Options.UniqueBasicBlockSectionNames =
539       CodeGenOpts.UniqueBasicBlockSectionNames;
540   Options.StackProtectorGuard =
541       llvm::StringSwitch<llvm::StackProtectorGuards>(CodeGenOpts
542           .StackProtectorGuard)
543           .Case("tls", llvm::StackProtectorGuards::TLS)
544           .Case("global", llvm::StackProtectorGuards::Global)
545           .Default(llvm::StackProtectorGuards::None);
546   Options.StackProtectorGuardOffset = CodeGenOpts.StackProtectorGuardOffset;
547   Options.StackProtectorGuardReg = CodeGenOpts.StackProtectorGuardReg;
548   Options.TLSSize = CodeGenOpts.TLSSize;
549   Options.EmulatedTLS = CodeGenOpts.EmulatedTLS;
550   Options.ExplicitEmulatedTLS = CodeGenOpts.ExplicitEmulatedTLS;
551   Options.DebuggerTuning = CodeGenOpts.getDebuggerTuning();
552   Options.EmitStackSizeSection = CodeGenOpts.StackSizeSection;
553   Options.EmitAddrsig = CodeGenOpts.Addrsig;
554   Options.ForceDwarfFrameSection = CodeGenOpts.ForceDwarfFrameSection;
555   Options.EmitCallSiteInfo = CodeGenOpts.EmitCallSiteInfo;
556   Options.ValueTrackingVariableLocations =
557       CodeGenOpts.ValueTrackingVariableLocations;
558   Options.XRayOmitFunctionIndex = CodeGenOpts.XRayOmitFunctionIndex;
559 
560   Options.MCOptions.SplitDwarfFile = CodeGenOpts.SplitDwarfFile;
561   Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
562   Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
563   Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
564   Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
565   Options.MCOptions.MCIncrementalLinkerCompatible =
566       CodeGenOpts.IncrementalLinkerCompatible;
567   Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
568   Options.MCOptions.MCNoWarn = CodeGenOpts.NoWarn;
569   Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
570   Options.MCOptions.PreserveAsmComments = CodeGenOpts.PreserveAsmComments;
571   Options.MCOptions.ABIName = TargetOpts.ABI;
572   for (const auto &Entry : HSOpts.UserEntries)
573     if (!Entry.IsFramework &&
574         (Entry.Group == frontend::IncludeDirGroup::Quoted ||
575          Entry.Group == frontend::IncludeDirGroup::Angled ||
576          Entry.Group == frontend::IncludeDirGroup::System))
577       Options.MCOptions.IASSearchPaths.push_back(
578           Entry.IgnoreSysRoot ? Entry.Path : HSOpts.Sysroot + Entry.Path);
579   Options.MCOptions.Argv0 = CodeGenOpts.Argv0;
580   Options.MCOptions.CommandLineArgs = CodeGenOpts.CommandLineArgs;
581 
582   return true;
583 }
584 
585 static Optional<GCOVOptions> getGCOVOptions(const CodeGenOptions &CodeGenOpts,
586                                             const LangOptions &LangOpts) {
587   if (!CodeGenOpts.EmitGcovArcs && !CodeGenOpts.EmitGcovNotes)
588     return None;
589   // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
590   // LLVM's -default-gcov-version flag is set to something invalid.
591   GCOVOptions Options;
592   Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
593   Options.EmitData = CodeGenOpts.EmitGcovArcs;
594   llvm::copy(CodeGenOpts.CoverageVersion, std::begin(Options.Version));
595   Options.NoRedZone = CodeGenOpts.DisableRedZone;
596   Options.Filter = CodeGenOpts.ProfileFilterFiles;
597   Options.Exclude = CodeGenOpts.ProfileExcludeFiles;
598   Options.Atomic = CodeGenOpts.AtomicProfileUpdate;
599   return Options;
600 }
601 
602 static Optional<InstrProfOptions>
603 getInstrProfOptions(const CodeGenOptions &CodeGenOpts,
604                     const LangOptions &LangOpts) {
605   if (!CodeGenOpts.hasProfileClangInstr())
606     return None;
607   InstrProfOptions Options;
608   Options.NoRedZone = CodeGenOpts.DisableRedZone;
609   Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
610   Options.Atomic = CodeGenOpts.AtomicProfileUpdate;
611   return Options;
612 }
613 
614 void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
615                                       legacy::FunctionPassManager &FPM) {
616   // Handle disabling of all LLVM passes, where we want to preserve the
617   // internal module before any optimization.
618   if (CodeGenOpts.DisableLLVMPasses)
619     return;
620 
621   // Figure out TargetLibraryInfo.  This needs to be added to MPM and FPM
622   // manually (and not via PMBuilder), since some passes (eg. InstrProfiling)
623   // are inserted before PMBuilder ones - they'd get the default-constructed
624   // TLI with an unknown target otherwise.
625   Triple TargetTriple(TheModule->getTargetTriple());
626   std::unique_ptr<TargetLibraryInfoImpl> TLII(
627       createTLII(TargetTriple, CodeGenOpts));
628 
629   // If we reached here with a non-empty index file name, then the index file
630   // was empty and we are not performing ThinLTO backend compilation (used in
631   // testing in a distributed build environment). Drop any the type test
632   // assume sequences inserted for whole program vtables so that codegen doesn't
633   // complain.
634   if (!CodeGenOpts.ThinLTOIndexFile.empty())
635     MPM.add(createLowerTypeTestsPass(/*ExportSummary=*/nullptr,
636                                      /*ImportSummary=*/nullptr,
637                                      /*DropTypeTests=*/true));
638 
639   PassManagerBuilderWrapper PMBuilder(TargetTriple, CodeGenOpts, LangOpts);
640 
641   // At O0 and O1 we only run the always inliner which is more efficient. At
642   // higher optimization levels we run the normal inliner.
643   if (CodeGenOpts.OptimizationLevel <= 1) {
644     bool InsertLifetimeIntrinsics = ((CodeGenOpts.OptimizationLevel != 0 &&
645                                       !CodeGenOpts.DisableLifetimeMarkers) ||
646                                      LangOpts.Coroutines);
647     PMBuilder.Inliner = createAlwaysInlinerLegacyPass(InsertLifetimeIntrinsics);
648   } else {
649     // We do not want to inline hot callsites for SamplePGO module-summary build
650     // because profile annotation will happen again in ThinLTO backend, and we
651     // want the IR of the hot path to match the profile.
652     PMBuilder.Inliner = createFunctionInliningPass(
653         CodeGenOpts.OptimizationLevel, CodeGenOpts.OptimizeSize,
654         (!CodeGenOpts.SampleProfileFile.empty() &&
655          CodeGenOpts.PrepareForThinLTO));
656   }
657 
658   PMBuilder.OptLevel = CodeGenOpts.OptimizationLevel;
659   PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
660   PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
661   PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
662   // Only enable CGProfilePass when using integrated assembler, since
663   // non-integrated assemblers don't recognize .cgprofile section.
664   PMBuilder.CallGraphProfile = !CodeGenOpts.DisableIntegratedAS;
665 
666   PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
667   // Loop interleaving in the loop vectorizer has historically been set to be
668   // enabled when loop unrolling is enabled.
669   PMBuilder.LoopsInterleaved = CodeGenOpts.UnrollLoops;
670   PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
671   PMBuilder.PrepareForThinLTO = CodeGenOpts.PrepareForThinLTO;
672   PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
673   PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
674 
675   MPM.add(new TargetLibraryInfoWrapperPass(*TLII));
676 
677   if (TM)
678     TM->adjustPassManager(PMBuilder);
679 
680   if (CodeGenOpts.DebugInfoForProfiling ||
681       !CodeGenOpts.SampleProfileFile.empty())
682     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
683                            addAddDiscriminatorsPass);
684 
685   // In ObjC ARC mode, add the main ARC optimization passes.
686   if (LangOpts.ObjCAutoRefCount) {
687     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
688                            addObjCARCExpandPass);
689     PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
690                            addObjCARCAPElimPass);
691     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
692                            addObjCARCOptPass);
693   }
694 
695   if (LangOpts.Coroutines)
696     addCoroutinePassesToExtensionPoints(PMBuilder);
697 
698   if (!CodeGenOpts.MemoryProfileOutput.empty()) {
699     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
700                            addMemProfilerPasses);
701     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
702                            addMemProfilerPasses);
703   }
704 
705   if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds)) {
706     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
707                            addBoundsCheckingPass);
708     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
709                            addBoundsCheckingPass);
710   }
711 
712   if (CodeGenOpts.SanitizeCoverageType ||
713       CodeGenOpts.SanitizeCoverageIndirectCalls ||
714       CodeGenOpts.SanitizeCoverageTraceCmp) {
715     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
716                            addSanitizerCoveragePass);
717     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
718                            addSanitizerCoveragePass);
719   }
720 
721   if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
722     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
723                            addAddressSanitizerPasses);
724     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
725                            addAddressSanitizerPasses);
726   }
727 
728   if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
729     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
730                            addKernelAddressSanitizerPasses);
731     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
732                            addKernelAddressSanitizerPasses);
733   }
734 
735   if (LangOpts.Sanitize.has(SanitizerKind::HWAddress)) {
736     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
737                            addHWAddressSanitizerPasses);
738     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
739                            addHWAddressSanitizerPasses);
740   }
741 
742   if (LangOpts.Sanitize.has(SanitizerKind::KernelHWAddress)) {
743     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
744                            addKernelHWAddressSanitizerPasses);
745     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
746                            addKernelHWAddressSanitizerPasses);
747   }
748 
749   if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
750     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
751                            addMemorySanitizerPass);
752     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
753                            addMemorySanitizerPass);
754   }
755 
756   if (LangOpts.Sanitize.has(SanitizerKind::KernelMemory)) {
757     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
758                            addKernelMemorySanitizerPass);
759     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
760                            addKernelMemorySanitizerPass);
761   }
762 
763   if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
764     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
765                            addThreadSanitizerPass);
766     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
767                            addThreadSanitizerPass);
768   }
769 
770   if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
771     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
772                            addDataFlowSanitizerPass);
773     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
774                            addDataFlowSanitizerPass);
775   }
776 
777   // Set up the per-function pass manager.
778   FPM.add(new TargetLibraryInfoWrapperPass(*TLII));
779   if (CodeGenOpts.VerifyModule)
780     FPM.add(createVerifierPass());
781 
782   // Set up the per-module pass manager.
783   if (!CodeGenOpts.RewriteMapFiles.empty())
784     addSymbolRewriterPass(CodeGenOpts, &MPM);
785 
786   // Add UniqueInternalLinkageNames Pass which renames internal linkage symbols
787   // with unique names.
788   if (CodeGenOpts.UniqueInternalLinkageNames) {
789     MPM.add(createUniqueInternalLinkageNamesPass());
790   }
791 
792   if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts, LangOpts)) {
793     MPM.add(createGCOVProfilerPass(*Options));
794     if (CodeGenOpts.getDebugInfo() == codegenoptions::NoDebugInfo)
795       MPM.add(createStripSymbolsPass(true));
796   }
797 
798   if (Optional<InstrProfOptions> Options =
799           getInstrProfOptions(CodeGenOpts, LangOpts))
800     MPM.add(createInstrProfilingLegacyPass(*Options, false));
801 
802   bool hasIRInstr = false;
803   if (CodeGenOpts.hasProfileIRInstr()) {
804     PMBuilder.EnablePGOInstrGen = true;
805     hasIRInstr = true;
806   }
807   if (CodeGenOpts.hasProfileCSIRInstr()) {
808     assert(!CodeGenOpts.hasProfileCSIRUse() &&
809            "Cannot have both CSProfileUse pass and CSProfileGen pass at the "
810            "same time");
811     assert(!hasIRInstr &&
812            "Cannot have both ProfileGen pass and CSProfileGen pass at the "
813            "same time");
814     PMBuilder.EnablePGOCSInstrGen = true;
815     hasIRInstr = true;
816   }
817   if (hasIRInstr) {
818     if (!CodeGenOpts.InstrProfileOutput.empty())
819       PMBuilder.PGOInstrGen = CodeGenOpts.InstrProfileOutput;
820     else
821       PMBuilder.PGOInstrGen = std::string(DefaultProfileGenName);
822   }
823   if (CodeGenOpts.hasProfileIRUse()) {
824     PMBuilder.PGOInstrUse = CodeGenOpts.ProfileInstrumentUsePath;
825     PMBuilder.EnablePGOCSInstrUse = CodeGenOpts.hasProfileCSIRUse();
826   }
827 
828   if (!CodeGenOpts.SampleProfileFile.empty())
829     PMBuilder.PGOSampleUse = CodeGenOpts.SampleProfileFile;
830 
831   PMBuilder.populateFunctionPassManager(FPM);
832   PMBuilder.populateModulePassManager(MPM);
833 }
834 
835 static void setCommandLineOpts(const CodeGenOptions &CodeGenOpts) {
836   SmallVector<const char *, 16> BackendArgs;
837   BackendArgs.push_back("clang"); // Fake program name.
838   if (!CodeGenOpts.DebugPass.empty()) {
839     BackendArgs.push_back("-debug-pass");
840     BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
841   }
842   if (!CodeGenOpts.LimitFloatPrecision.empty()) {
843     BackendArgs.push_back("-limit-float-precision");
844     BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
845   }
846   BackendArgs.push_back(nullptr);
847   llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
848                                     BackendArgs.data());
849 }
850 
851 void EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
852   // Create the TargetMachine for generating code.
853   std::string Error;
854   std::string Triple = TheModule->getTargetTriple();
855   const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
856   if (!TheTarget) {
857     if (MustCreateTM)
858       Diags.Report(diag::err_fe_unable_to_create_target) << Error;
859     return;
860   }
861 
862   Optional<llvm::CodeModel::Model> CM = getCodeModel(CodeGenOpts);
863   std::string FeaturesStr =
864       llvm::join(TargetOpts.Features.begin(), TargetOpts.Features.end(), ",");
865   llvm::Reloc::Model RM = CodeGenOpts.RelocationModel;
866   CodeGenOpt::Level OptLevel = getCGOptLevel(CodeGenOpts);
867 
868   llvm::TargetOptions Options;
869   if (!initTargetOptions(Diags, Options, CodeGenOpts, TargetOpts, LangOpts,
870                          HSOpts))
871     return;
872   TM.reset(TheTarget->createTargetMachine(Triple, TargetOpts.CPU, FeaturesStr,
873                                           Options, RM, CM, OptLevel));
874 }
875 
876 bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
877                                        BackendAction Action,
878                                        raw_pwrite_stream &OS,
879                                        raw_pwrite_stream *DwoOS) {
880   // Add LibraryInfo.
881   llvm::Triple TargetTriple(TheModule->getTargetTriple());
882   std::unique_ptr<TargetLibraryInfoImpl> TLII(
883       createTLII(TargetTriple, CodeGenOpts));
884   CodeGenPasses.add(new TargetLibraryInfoWrapperPass(*TLII));
885 
886   // Normal mode, emit a .s or .o file by running the code generator. Note,
887   // this also adds codegenerator level optimization passes.
888   CodeGenFileType CGFT = getCodeGenFileType(Action);
889 
890   // Add ObjC ARC final-cleanup optimizations. This is done as part of the
891   // "codegen" passes so that it isn't run multiple times when there is
892   // inlining happening.
893   if (CodeGenOpts.OptimizationLevel > 0)
894     CodeGenPasses.add(createObjCARCContractPass());
895 
896   if (TM->addPassesToEmitFile(CodeGenPasses, OS, DwoOS, CGFT,
897                               /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
898     Diags.Report(diag::err_fe_unable_to_interface_with_target);
899     return false;
900   }
901 
902   return true;
903 }
904 
905 void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
906                                       std::unique_ptr<raw_pwrite_stream> OS) {
907   TimeRegion Region(FrontendTimesIsEnabled ? &CodeGenerationTime : nullptr);
908 
909   setCommandLineOpts(CodeGenOpts);
910 
911   bool UsesCodeGen = (Action != Backend_EmitNothing &&
912                       Action != Backend_EmitBC &&
913                       Action != Backend_EmitLL);
914   CreateTargetMachine(UsesCodeGen);
915 
916   if (UsesCodeGen && !TM)
917     return;
918   if (TM)
919     TheModule->setDataLayout(TM->createDataLayout());
920 
921   legacy::PassManager PerModulePasses;
922   PerModulePasses.add(
923       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
924 
925   legacy::FunctionPassManager PerFunctionPasses(TheModule);
926   PerFunctionPasses.add(
927       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
928 
929   CreatePasses(PerModulePasses, PerFunctionPasses);
930 
931   legacy::PassManager CodeGenPasses;
932   CodeGenPasses.add(
933       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
934 
935   std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
936 
937   switch (Action) {
938   case Backend_EmitNothing:
939     break;
940 
941   case Backend_EmitBC:
942     if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
943       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
944         ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
945         if (!ThinLinkOS)
946           return;
947       }
948       TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
949                                CodeGenOpts.EnableSplitLTOUnit);
950       PerModulePasses.add(createWriteThinLTOBitcodePass(
951           *OS, ThinLinkOS ? &ThinLinkOS->os() : nullptr));
952     } else {
953       // Emit a module summary by default for Regular LTO except for ld64
954       // targets
955       bool EmitLTOSummary =
956           (CodeGenOpts.PrepareForLTO &&
957            !CodeGenOpts.DisableLLVMPasses &&
958            llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
959                llvm::Triple::Apple);
960       if (EmitLTOSummary) {
961         if (!TheModule->getModuleFlag("ThinLTO"))
962           TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
963         TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
964                                  uint32_t(1));
965       }
966 
967       PerModulePasses.add(createBitcodeWriterPass(
968           *OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
969     }
970     break;
971 
972   case Backend_EmitLL:
973     PerModulePasses.add(
974         createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
975     break;
976 
977   default:
978     if (!CodeGenOpts.SplitDwarfOutput.empty()) {
979       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
980       if (!DwoOS)
981         return;
982     }
983     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
984                        DwoOS ? &DwoOS->os() : nullptr))
985       return;
986   }
987 
988   // Before executing passes, print the final values of the LLVM options.
989   cl::PrintOptionValues();
990 
991   // Run passes. For now we do all passes at once, but eventually we
992   // would like to have the option of streaming code generation.
993 
994   {
995     PrettyStackTraceString CrashInfo("Per-function optimization");
996     llvm::TimeTraceScope TimeScope("PerFunctionPasses");
997 
998     PerFunctionPasses.doInitialization();
999     for (Function &F : *TheModule)
1000       if (!F.isDeclaration())
1001         PerFunctionPasses.run(F);
1002     PerFunctionPasses.doFinalization();
1003   }
1004 
1005   {
1006     PrettyStackTraceString CrashInfo("Per-module optimization passes");
1007     llvm::TimeTraceScope TimeScope("PerModulePasses");
1008     PerModulePasses.run(*TheModule);
1009   }
1010 
1011   {
1012     PrettyStackTraceString CrashInfo("Code generation");
1013     llvm::TimeTraceScope TimeScope("CodeGenPasses");
1014     CodeGenPasses.run(*TheModule);
1015   }
1016 
1017   if (ThinLinkOS)
1018     ThinLinkOS->keep();
1019   if (DwoOS)
1020     DwoOS->keep();
1021 }
1022 
1023 static PassBuilder::OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
1024   switch (Opts.OptimizationLevel) {
1025   default:
1026     llvm_unreachable("Invalid optimization level!");
1027 
1028   case 0:
1029     return PassBuilder::OptimizationLevel::O0;
1030 
1031   case 1:
1032     return PassBuilder::OptimizationLevel::O1;
1033 
1034   case 2:
1035     switch (Opts.OptimizeSize) {
1036     default:
1037       llvm_unreachable("Invalid optimization level for size!");
1038 
1039     case 0:
1040       return PassBuilder::OptimizationLevel::O2;
1041 
1042     case 1:
1043       return PassBuilder::OptimizationLevel::Os;
1044 
1045     case 2:
1046       return PassBuilder::OptimizationLevel::Oz;
1047     }
1048 
1049   case 3:
1050     return PassBuilder::OptimizationLevel::O3;
1051   }
1052 }
1053 
1054 /// A clean version of `EmitAssembly` that uses the new pass manager.
1055 ///
1056 /// Not all features are currently supported in this system, but where
1057 /// necessary it falls back to the legacy pass manager to at least provide
1058 /// basic functionality.
1059 ///
1060 /// This API is planned to have its functionality finished and then to replace
1061 /// `EmitAssembly` at some point in the future when the default switches.
1062 void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
1063     BackendAction Action, std::unique_ptr<raw_pwrite_stream> OS) {
1064   TimeRegion Region(FrontendTimesIsEnabled ? &CodeGenerationTime : nullptr);
1065   setCommandLineOpts(CodeGenOpts);
1066 
1067   bool RequiresCodeGen = (Action != Backend_EmitNothing &&
1068                           Action != Backend_EmitBC &&
1069                           Action != Backend_EmitLL);
1070   CreateTargetMachine(RequiresCodeGen);
1071 
1072   if (RequiresCodeGen && !TM)
1073     return;
1074   if (TM)
1075     TheModule->setDataLayout(TM->createDataLayout());
1076 
1077   Optional<PGOOptions> PGOOpt;
1078 
1079   if (CodeGenOpts.hasProfileIRInstr())
1080     // -fprofile-generate.
1081     PGOOpt = PGOOptions(CodeGenOpts.InstrProfileOutput.empty()
1082                             ? std::string(DefaultProfileGenName)
1083                             : CodeGenOpts.InstrProfileOutput,
1084                         "", "", PGOOptions::IRInstr, PGOOptions::NoCSAction,
1085                         CodeGenOpts.DebugInfoForProfiling);
1086   else if (CodeGenOpts.hasProfileIRUse()) {
1087     // -fprofile-use.
1088     auto CSAction = CodeGenOpts.hasProfileCSIRUse() ? PGOOptions::CSIRUse
1089                                                     : PGOOptions::NoCSAction;
1090     PGOOpt = PGOOptions(CodeGenOpts.ProfileInstrumentUsePath, "",
1091                         CodeGenOpts.ProfileRemappingFile, PGOOptions::IRUse,
1092                         CSAction, CodeGenOpts.DebugInfoForProfiling);
1093   } else if (!CodeGenOpts.SampleProfileFile.empty())
1094     // -fprofile-sample-use
1095     PGOOpt =
1096         PGOOptions(CodeGenOpts.SampleProfileFile, "",
1097                    CodeGenOpts.ProfileRemappingFile, PGOOptions::SampleUse,
1098                    PGOOptions::NoCSAction, CodeGenOpts.DebugInfoForProfiling);
1099   else if (CodeGenOpts.DebugInfoForProfiling)
1100     // -fdebug-info-for-profiling
1101     PGOOpt = PGOOptions("", "", "", PGOOptions::NoAction,
1102                         PGOOptions::NoCSAction, true);
1103 
1104   // Check to see if we want to generate a CS profile.
1105   if (CodeGenOpts.hasProfileCSIRInstr()) {
1106     assert(!CodeGenOpts.hasProfileCSIRUse() &&
1107            "Cannot have both CSProfileUse pass and CSProfileGen pass at "
1108            "the same time");
1109     if (PGOOpt.hasValue()) {
1110       assert(PGOOpt->Action != PGOOptions::IRInstr &&
1111              PGOOpt->Action != PGOOptions::SampleUse &&
1112              "Cannot run CSProfileGen pass with ProfileGen or SampleUse "
1113              " pass");
1114       PGOOpt->CSProfileGenFile = CodeGenOpts.InstrProfileOutput.empty()
1115                                      ? std::string(DefaultProfileGenName)
1116                                      : CodeGenOpts.InstrProfileOutput;
1117       PGOOpt->CSAction = PGOOptions::CSIRInstr;
1118     } else
1119       PGOOpt = PGOOptions("",
1120                           CodeGenOpts.InstrProfileOutput.empty()
1121                               ? std::string(DefaultProfileGenName)
1122                               : CodeGenOpts.InstrProfileOutput,
1123                           "", PGOOptions::NoAction, PGOOptions::CSIRInstr,
1124                           CodeGenOpts.DebugInfoForProfiling);
1125   }
1126 
1127   PipelineTuningOptions PTO;
1128   PTO.LoopUnrolling = CodeGenOpts.UnrollLoops;
1129   // For historical reasons, loop interleaving is set to mirror setting for loop
1130   // unrolling.
1131   PTO.LoopInterleaving = CodeGenOpts.UnrollLoops;
1132   PTO.LoopVectorization = CodeGenOpts.VectorizeLoop;
1133   PTO.SLPVectorization = CodeGenOpts.VectorizeSLP;
1134   // Only enable CGProfilePass when using integrated assembler, since
1135   // non-integrated assemblers don't recognize .cgprofile section.
1136   PTO.CallGraphProfile = !CodeGenOpts.DisableIntegratedAS;
1137   PTO.Coroutines = LangOpts.Coroutines;
1138 
1139   PassInstrumentationCallbacks PIC;
1140   StandardInstrumentations SI(CodeGenOpts.DebugPassManager);
1141   SI.registerCallbacks(PIC);
1142   PassBuilder PB(CodeGenOpts.DebugPassManager, TM.get(), PTO, PGOOpt, &PIC);
1143 
1144   // Attempt to load pass plugins and register their callbacks with PB.
1145   for (auto &PluginFN : CodeGenOpts.PassPlugins) {
1146     auto PassPlugin = PassPlugin::Load(PluginFN);
1147     if (PassPlugin) {
1148       PassPlugin->registerPassBuilderCallbacks(PB);
1149     } else {
1150       Diags.Report(diag::err_fe_unable_to_load_plugin)
1151           << PluginFN << toString(PassPlugin.takeError());
1152     }
1153   }
1154 #define HANDLE_EXTENSION(Ext)                                                  \
1155   get##Ext##PluginInfo().RegisterPassBuilderCallbacks(PB);
1156 #include "llvm/Support/Extension.def"
1157 
1158   LoopAnalysisManager LAM(CodeGenOpts.DebugPassManager);
1159   FunctionAnalysisManager FAM(CodeGenOpts.DebugPassManager);
1160   CGSCCAnalysisManager CGAM(CodeGenOpts.DebugPassManager);
1161   ModuleAnalysisManager MAM(CodeGenOpts.DebugPassManager);
1162 
1163   // Register the AA manager first so that our version is the one used.
1164   FAM.registerPass([&] { return PB.buildDefaultAAPipeline(); });
1165 
1166   // Register the target library analysis directly and give it a customized
1167   // preset TLI.
1168   Triple TargetTriple(TheModule->getTargetTriple());
1169   std::unique_ptr<TargetLibraryInfoImpl> TLII(
1170       createTLII(TargetTriple, CodeGenOpts));
1171   FAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); });
1172 
1173   // Register all the basic analyses with the managers.
1174   PB.registerModuleAnalyses(MAM);
1175   PB.registerCGSCCAnalyses(CGAM);
1176   PB.registerFunctionAnalyses(FAM);
1177   PB.registerLoopAnalyses(LAM);
1178   PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
1179 
1180   ModulePassManager MPM(CodeGenOpts.DebugPassManager);
1181 
1182   if (!CodeGenOpts.DisableLLVMPasses) {
1183     // Map our optimization levels into one of the distinct levels used to
1184     // configure the pipeline.
1185     PassBuilder::OptimizationLevel Level = mapToLevel(CodeGenOpts);
1186 
1187     bool IsThinLTO = CodeGenOpts.PrepareForThinLTO;
1188     bool IsLTO = CodeGenOpts.PrepareForLTO;
1189 
1190     // If we reached here with a non-empty index file name, then the index
1191     // file was empty and we are not performing ThinLTO backend compilation
1192     // (used in testing in a distributed build environment). Drop any the type
1193     // test assume sequences inserted for whole program vtables so that
1194     // codegen doesn't complain.
1195     if (!CodeGenOpts.ThinLTOIndexFile.empty())
1196       PB.registerPipelineStartEPCallback(
1197           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1198             MPM.addPass(LowerTypeTestsPass(/*ExportSummary=*/nullptr,
1199                                            /*ImportSummary=*/nullptr,
1200                                            /*DropTypeTests=*/true));
1201           });
1202 
1203     if (Level != PassBuilder::OptimizationLevel::O0) {
1204       PB.registerPipelineStartEPCallback(
1205           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1206             MPM.addPass(createModuleToFunctionPassAdaptor(
1207                 EntryExitInstrumenterPass(/*PostInlining=*/false)));
1208           });
1209     }
1210 
1211     // Register callbacks to schedule sanitizer passes at the appropriate part
1212     // of the pipeline.
1213     if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
1214       PB.registerScalarOptimizerLateEPCallback(
1215           [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
1216             FPM.addPass(BoundsCheckingPass());
1217           });
1218 
1219     if (CodeGenOpts.SanitizeCoverageType ||
1220         CodeGenOpts.SanitizeCoverageIndirectCalls ||
1221         CodeGenOpts.SanitizeCoverageTraceCmp) {
1222       PB.registerOptimizerLastEPCallback(
1223           [this](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1224             auto SancovOpts = getSancovOptsFromCGOpts(CodeGenOpts);
1225             MPM.addPass(ModuleSanitizerCoveragePass(
1226                 SancovOpts, CodeGenOpts.SanitizeCoverageAllowlistFiles,
1227                 CodeGenOpts.SanitizeCoverageBlocklistFiles));
1228           });
1229     }
1230 
1231     if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
1232       int TrackOrigins = CodeGenOpts.SanitizeMemoryTrackOrigins;
1233       bool Recover = CodeGenOpts.SanitizeRecover.has(SanitizerKind::Memory);
1234       PB.registerOptimizerLastEPCallback(
1235           [TrackOrigins, Recover](ModulePassManager &MPM,
1236                                   PassBuilder::OptimizationLevel Level) {
1237             MPM.addPass(MemorySanitizerPass({TrackOrigins, Recover, false}));
1238             MPM.addPass(createModuleToFunctionPassAdaptor(
1239                 MemorySanitizerPass({TrackOrigins, Recover, false})));
1240           });
1241     }
1242     if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
1243       PB.registerOptimizerLastEPCallback(
1244           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1245             MPM.addPass(ThreadSanitizerPass());
1246             MPM.addPass(
1247                 createModuleToFunctionPassAdaptor(ThreadSanitizerPass()));
1248           });
1249     }
1250 
1251     auto ASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
1252       if (LangOpts.Sanitize.has(Mask)) {
1253         bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
1254         bool UseAfterScope = CodeGenOpts.SanitizeAddressUseAfterScope;
1255         bool ModuleUseAfterScope = asanUseGlobalsGC(TargetTriple, CodeGenOpts);
1256         bool UseOdrIndicator = CodeGenOpts.SanitizeAddressUseOdrIndicator;
1257         PB.registerOptimizerLastEPCallback(
1258             [CompileKernel, Recover, UseAfterScope, ModuleUseAfterScope,
1259              UseOdrIndicator](ModulePassManager &MPM,
1260                               PassBuilder::OptimizationLevel Level) {
1261               MPM.addPass(
1262                   RequireAnalysisPass<ASanGlobalsMetadataAnalysis, Module>());
1263               MPM.addPass(ModuleAddressSanitizerPass(CompileKernel, Recover,
1264                                                      ModuleUseAfterScope,
1265                                                      UseOdrIndicator));
1266               MPM.addPass(createModuleToFunctionPassAdaptor(
1267                   AddressSanitizerPass(CompileKernel, Recover, UseAfterScope)));
1268             });
1269       }
1270     };
1271     ASanPass(SanitizerKind::Address, false);
1272     ASanPass(SanitizerKind::KernelAddress, true);
1273 
1274     auto HWASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
1275       if (LangOpts.Sanitize.has(Mask)) {
1276         bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
1277         PB.registerOptimizerLastEPCallback(
1278             [CompileKernel, Recover](ModulePassManager &MPM,
1279                                      PassBuilder::OptimizationLevel Level) {
1280               MPM.addPass(HWAddressSanitizerPass(CompileKernel, Recover));
1281             });
1282       }
1283     };
1284     HWASanPass(SanitizerKind::HWAddress, false);
1285     HWASanPass(SanitizerKind::KernelHWAddress, true);
1286 
1287     if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
1288       PB.registerOptimizerLastEPCallback(
1289           [this](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1290             MPM.addPass(
1291                 DataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
1292           });
1293     }
1294 
1295     if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts, LangOpts))
1296       PB.registerPipelineStartEPCallback(
1297           [Options](ModulePassManager &MPM,
1298                     PassBuilder::OptimizationLevel Level) {
1299             MPM.addPass(GCOVProfilerPass(*Options));
1300           });
1301     if (Optional<InstrProfOptions> Options =
1302             getInstrProfOptions(CodeGenOpts, LangOpts))
1303       PB.registerPipelineStartEPCallback(
1304           [Options](ModulePassManager &MPM,
1305                     PassBuilder::OptimizationLevel Level) {
1306             MPM.addPass(InstrProfiling(*Options, false));
1307           });
1308 
1309     if (CodeGenOpts.OptimizationLevel == 0) {
1310       MPM = PB.buildO0DefaultPipeline(Level, IsLTO || IsThinLTO);
1311     } else if (IsThinLTO) {
1312       MPM = PB.buildThinLTOPreLinkDefaultPipeline(Level);
1313     } else if (IsLTO) {
1314       MPM = PB.buildLTOPreLinkDefaultPipeline(Level);
1315     } else {
1316       MPM = PB.buildPerModuleDefaultPipeline(Level);
1317     }
1318 
1319     // Add UniqueInternalLinkageNames Pass which renames internal linkage
1320     // symbols with unique names.
1321     if (CodeGenOpts.UniqueInternalLinkageNames)
1322       MPM.addPass(UniqueInternalLinkageNamesPass());
1323 
1324     if (!CodeGenOpts.MemoryProfileOutput.empty()) {
1325       MPM.addPass(createModuleToFunctionPassAdaptor(MemProfilerPass()));
1326       MPM.addPass(ModuleMemProfilerPass());
1327     }
1328   }
1329 
1330   // FIXME: We still use the legacy pass manager to do code generation. We
1331   // create that pass manager here and use it as needed below.
1332   legacy::PassManager CodeGenPasses;
1333   bool NeedCodeGen = false;
1334   std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
1335 
1336   // Append any output we need to the pass manager.
1337   switch (Action) {
1338   case Backend_EmitNothing:
1339     break;
1340 
1341   case Backend_EmitBC:
1342     if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
1343       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
1344         ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
1345         if (!ThinLinkOS)
1346           return;
1347       }
1348       TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1349                                CodeGenOpts.EnableSplitLTOUnit);
1350       MPM.addPass(ThinLTOBitcodeWriterPass(*OS, ThinLinkOS ? &ThinLinkOS->os()
1351                                                            : nullptr));
1352     } else {
1353       // Emit a module summary by default for Regular LTO except for ld64
1354       // targets
1355       bool EmitLTOSummary =
1356           (CodeGenOpts.PrepareForLTO &&
1357            !CodeGenOpts.DisableLLVMPasses &&
1358            llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
1359                llvm::Triple::Apple);
1360       if (EmitLTOSummary) {
1361         if (!TheModule->getModuleFlag("ThinLTO"))
1362           TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
1363         TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1364                                  uint32_t(1));
1365       }
1366       MPM.addPass(
1367           BitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
1368     }
1369     break;
1370 
1371   case Backend_EmitLL:
1372     MPM.addPass(PrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
1373     break;
1374 
1375   case Backend_EmitAssembly:
1376   case Backend_EmitMCNull:
1377   case Backend_EmitObj:
1378     NeedCodeGen = true;
1379     CodeGenPasses.add(
1380         createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
1381     if (!CodeGenOpts.SplitDwarfOutput.empty()) {
1382       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
1383       if (!DwoOS)
1384         return;
1385     }
1386     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
1387                        DwoOS ? &DwoOS->os() : nullptr))
1388       // FIXME: Should we handle this error differently?
1389       return;
1390     break;
1391   }
1392 
1393   // Before executing passes, print the final values of the LLVM options.
1394   cl::PrintOptionValues();
1395 
1396   // Now that we have all of the passes ready, run them.
1397   {
1398     PrettyStackTraceString CrashInfo("Optimizer");
1399     MPM.run(*TheModule, MAM);
1400   }
1401 
1402   // Now if needed, run the legacy PM for codegen.
1403   if (NeedCodeGen) {
1404     PrettyStackTraceString CrashInfo("Code generation");
1405     CodeGenPasses.run(*TheModule);
1406   }
1407 
1408   if (ThinLinkOS)
1409     ThinLinkOS->keep();
1410   if (DwoOS)
1411     DwoOS->keep();
1412 }
1413 
1414 static void runThinLTOBackend(
1415     DiagnosticsEngine &Diags, ModuleSummaryIndex *CombinedIndex, Module *M,
1416     const HeaderSearchOptions &HeaderOpts, const CodeGenOptions &CGOpts,
1417     const clang::TargetOptions &TOpts, const LangOptions &LOpts,
1418     std::unique_ptr<raw_pwrite_stream> OS, std::string SampleProfile,
1419     std::string ProfileRemapping, BackendAction Action) {
1420   StringMap<DenseMap<GlobalValue::GUID, GlobalValueSummary *>>
1421       ModuleToDefinedGVSummaries;
1422   CombinedIndex->collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries);
1423 
1424   setCommandLineOpts(CGOpts);
1425 
1426   // We can simply import the values mentioned in the combined index, since
1427   // we should only invoke this using the individual indexes written out
1428   // via a WriteIndexesThinBackend.
1429   FunctionImporter::ImportMapTy ImportList;
1430   std::vector<std::unique_ptr<llvm::MemoryBuffer>> OwnedImports;
1431   MapVector<llvm::StringRef, llvm::BitcodeModule> ModuleMap;
1432   if (!lto::loadReferencedModules(*M, *CombinedIndex, ImportList, ModuleMap,
1433                                   OwnedImports))
1434     return;
1435 
1436   auto AddStream = [&](size_t Task) {
1437     return std::make_unique<lto::NativeObjectStream>(std::move(OS));
1438   };
1439   lto::Config Conf;
1440   if (CGOpts.SaveTempsFilePrefix != "") {
1441     if (Error E = Conf.addSaveTemps(CGOpts.SaveTempsFilePrefix + ".",
1442                                     /* UseInputModulePath */ false)) {
1443       handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1444         errs() << "Error setting up ThinLTO save-temps: " << EIB.message()
1445                << '\n';
1446       });
1447     }
1448   }
1449   Conf.CPU = TOpts.CPU;
1450   Conf.CodeModel = getCodeModel(CGOpts);
1451   Conf.MAttrs = TOpts.Features;
1452   Conf.RelocModel = CGOpts.RelocationModel;
1453   Conf.CGOptLevel = getCGOptLevel(CGOpts);
1454   Conf.OptLevel = CGOpts.OptimizationLevel;
1455   initTargetOptions(Diags, Conf.Options, CGOpts, TOpts, LOpts, HeaderOpts);
1456   Conf.SampleProfile = std::move(SampleProfile);
1457   Conf.PTO.LoopUnrolling = CGOpts.UnrollLoops;
1458   // For historical reasons, loop interleaving is set to mirror setting for loop
1459   // unrolling.
1460   Conf.PTO.LoopInterleaving = CGOpts.UnrollLoops;
1461   Conf.PTO.LoopVectorization = CGOpts.VectorizeLoop;
1462   Conf.PTO.SLPVectorization = CGOpts.VectorizeSLP;
1463   // Only enable CGProfilePass when using integrated assembler, since
1464   // non-integrated assemblers don't recognize .cgprofile section.
1465   Conf.PTO.CallGraphProfile = !CGOpts.DisableIntegratedAS;
1466 
1467   // Context sensitive profile.
1468   if (CGOpts.hasProfileCSIRInstr()) {
1469     Conf.RunCSIRInstr = true;
1470     Conf.CSIRProfile = std::move(CGOpts.InstrProfileOutput);
1471   } else if (CGOpts.hasProfileCSIRUse()) {
1472     Conf.RunCSIRInstr = false;
1473     Conf.CSIRProfile = std::move(CGOpts.ProfileInstrumentUsePath);
1474   }
1475 
1476   Conf.ProfileRemapping = std::move(ProfileRemapping);
1477   Conf.UseNewPM = CGOpts.ExperimentalNewPassManager;
1478   Conf.DebugPassManager = CGOpts.DebugPassManager;
1479   Conf.RemarksWithHotness = CGOpts.DiagnosticsWithHotness;
1480   Conf.RemarksFilename = CGOpts.OptRecordFile;
1481   Conf.RemarksPasses = CGOpts.OptRecordPasses;
1482   Conf.RemarksFormat = CGOpts.OptRecordFormat;
1483   Conf.SplitDwarfFile = CGOpts.SplitDwarfFile;
1484   Conf.SplitDwarfOutput = CGOpts.SplitDwarfOutput;
1485   switch (Action) {
1486   case Backend_EmitNothing:
1487     Conf.PreCodeGenModuleHook = [](size_t Task, const Module &Mod) {
1488       return false;
1489     };
1490     break;
1491   case Backend_EmitLL:
1492     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1493       M->print(*OS, nullptr, CGOpts.EmitLLVMUseLists);
1494       return false;
1495     };
1496     break;
1497   case Backend_EmitBC:
1498     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1499       WriteBitcodeToFile(*M, *OS, CGOpts.EmitLLVMUseLists);
1500       return false;
1501     };
1502     break;
1503   default:
1504     Conf.CGFileType = getCodeGenFileType(Action);
1505     break;
1506   }
1507   if (Error E =
1508           thinBackend(Conf, -1, AddStream, *M, *CombinedIndex, ImportList,
1509                       ModuleToDefinedGVSummaries[M->getModuleIdentifier()],
1510                       ModuleMap, CGOpts.CmdArgs)) {
1511     handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1512       errs() << "Error running ThinLTO backend: " << EIB.message() << '\n';
1513     });
1514   }
1515 }
1516 
1517 void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
1518                               const HeaderSearchOptions &HeaderOpts,
1519                               const CodeGenOptions &CGOpts,
1520                               const clang::TargetOptions &TOpts,
1521                               const LangOptions &LOpts,
1522                               const llvm::DataLayout &TDesc, Module *M,
1523                               BackendAction Action,
1524                               std::unique_ptr<raw_pwrite_stream> OS) {
1525 
1526   llvm::TimeTraceScope TimeScope("Backend");
1527 
1528   std::unique_ptr<llvm::Module> EmptyModule;
1529   if (!CGOpts.ThinLTOIndexFile.empty()) {
1530     // If we are performing a ThinLTO importing compile, load the function index
1531     // into memory and pass it into runThinLTOBackend, which will run the
1532     // function importer and invoke LTO passes.
1533     Expected<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
1534         llvm::getModuleSummaryIndexForFile(CGOpts.ThinLTOIndexFile,
1535                                            /*IgnoreEmptyThinLTOIndexFile*/true);
1536     if (!IndexOrErr) {
1537       logAllUnhandledErrors(IndexOrErr.takeError(), errs(),
1538                             "Error loading index file '" +
1539                             CGOpts.ThinLTOIndexFile + "': ");
1540       return;
1541     }
1542     std::unique_ptr<ModuleSummaryIndex> CombinedIndex = std::move(*IndexOrErr);
1543     // A null CombinedIndex means we should skip ThinLTO compilation
1544     // (LLVM will optionally ignore empty index files, returning null instead
1545     // of an error).
1546     if (CombinedIndex) {
1547       if (!CombinedIndex->skipModuleByDistributedBackend()) {
1548         runThinLTOBackend(Diags, CombinedIndex.get(), M, HeaderOpts, CGOpts,
1549                           TOpts, LOpts, std::move(OS), CGOpts.SampleProfileFile,
1550                           CGOpts.ProfileRemappingFile, Action);
1551         return;
1552       }
1553       // Distributed indexing detected that nothing from the module is needed
1554       // for the final linking. So we can skip the compilation. We sill need to
1555       // output an empty object file to make sure that a linker does not fail
1556       // trying to read it. Also for some features, like CFI, we must skip
1557       // the compilation as CombinedIndex does not contain all required
1558       // information.
1559       EmptyModule = std::make_unique<llvm::Module>("empty", M->getContext());
1560       EmptyModule->setTargetTriple(M->getTargetTriple());
1561       M = EmptyModule.get();
1562     }
1563   }
1564 
1565   EmitAssemblyHelper AsmHelper(Diags, HeaderOpts, CGOpts, TOpts, LOpts, M);
1566 
1567   if (CGOpts.ExperimentalNewPassManager)
1568     AsmHelper.EmitAssemblyWithNewPassManager(Action, std::move(OS));
1569   else
1570     AsmHelper.EmitAssembly(Action, std::move(OS));
1571 
1572   // Verify clang's TargetInfo DataLayout against the LLVM TargetMachine's
1573   // DataLayout.
1574   if (AsmHelper.TM) {
1575     std::string DLDesc = M->getDataLayout().getStringRepresentation();
1576     if (DLDesc != TDesc.getStringRepresentation()) {
1577       unsigned DiagID = Diags.getCustomDiagID(
1578           DiagnosticsEngine::Error, "backend data layout '%0' does not match "
1579                                     "expected target description '%1'");
1580       Diags.Report(DiagID) << DLDesc << TDesc.getStringRepresentation();
1581     }
1582   }
1583 }
1584 
1585 // With -fembed-bitcode, save a copy of the llvm IR as data in the
1586 // __LLVM,__bitcode section.
1587 void clang::EmbedBitcode(llvm::Module *M, const CodeGenOptions &CGOpts,
1588                          llvm::MemoryBufferRef Buf) {
1589   if (CGOpts.getEmbedBitcode() == CodeGenOptions::Embed_Off)
1590     return;
1591   llvm::EmbedBitcodeInModule(
1592       *M, Buf, CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Marker,
1593       CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Bitcode,
1594       CGOpts.CmdArgs);
1595 }
1596