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.ValueTrackingVariableLocations =
558       CodeGenOpts.ValueTrackingVariableLocations;
559   Options.XRayOmitFunctionIndex = CodeGenOpts.XRayOmitFunctionIndex;
560 
561   Options.MCOptions.SplitDwarfFile = CodeGenOpts.SplitDwarfFile;
562   Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
563   Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
564   Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
565   Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
566   Options.MCOptions.MCIncrementalLinkerCompatible =
567       CodeGenOpts.IncrementalLinkerCompatible;
568   Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
569   Options.MCOptions.MCNoWarn = CodeGenOpts.NoWarn;
570   Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
571   Options.MCOptions.PreserveAsmComments = CodeGenOpts.PreserveAsmComments;
572   Options.MCOptions.ABIName = TargetOpts.ABI;
573   for (const auto &Entry : HSOpts.UserEntries)
574     if (!Entry.IsFramework &&
575         (Entry.Group == frontend::IncludeDirGroup::Quoted ||
576          Entry.Group == frontend::IncludeDirGroup::Angled ||
577          Entry.Group == frontend::IncludeDirGroup::System))
578       Options.MCOptions.IASSearchPaths.push_back(
579           Entry.IgnoreSysRoot ? Entry.Path : HSOpts.Sysroot + Entry.Path);
580   Options.MCOptions.Argv0 = CodeGenOpts.Argv0;
581   Options.MCOptions.CommandLineArgs = CodeGenOpts.CommandLineArgs;
582 
583   return true;
584 }
585 
586 static Optional<GCOVOptions> getGCOVOptions(const CodeGenOptions &CodeGenOpts,
587                                             const LangOptions &LangOpts) {
588   if (!CodeGenOpts.EmitGcovArcs && !CodeGenOpts.EmitGcovNotes)
589     return None;
590   // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
591   // LLVM's -default-gcov-version flag is set to something invalid.
592   GCOVOptions Options;
593   Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
594   Options.EmitData = CodeGenOpts.EmitGcovArcs;
595   llvm::copy(CodeGenOpts.CoverageVersion, std::begin(Options.Version));
596   Options.NoRedZone = CodeGenOpts.DisableRedZone;
597   Options.Filter = CodeGenOpts.ProfileFilterFiles;
598   Options.Exclude = CodeGenOpts.ProfileExcludeFiles;
599   Options.Atomic = CodeGenOpts.AtomicProfileUpdate;
600   return Options;
601 }
602 
603 static Optional<InstrProfOptions>
604 getInstrProfOptions(const CodeGenOptions &CodeGenOpts,
605                     const LangOptions &LangOpts) {
606   if (!CodeGenOpts.hasProfileClangInstr())
607     return None;
608   InstrProfOptions Options;
609   Options.NoRedZone = CodeGenOpts.DisableRedZone;
610   Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
611   Options.Atomic = CodeGenOpts.AtomicProfileUpdate;
612   return Options;
613 }
614 
615 void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
616                                       legacy::FunctionPassManager &FPM) {
617   // Handle disabling of all LLVM passes, where we want to preserve the
618   // internal module before any optimization.
619   if (CodeGenOpts.DisableLLVMPasses)
620     return;
621 
622   // Figure out TargetLibraryInfo.  This needs to be added to MPM and FPM
623   // manually (and not via PMBuilder), since some passes (eg. InstrProfiling)
624   // are inserted before PMBuilder ones - they'd get the default-constructed
625   // TLI with an unknown target otherwise.
626   Triple TargetTriple(TheModule->getTargetTriple());
627   std::unique_ptr<TargetLibraryInfoImpl> TLII(
628       createTLII(TargetTriple, CodeGenOpts));
629 
630   // If we reached here with a non-empty index file name, then the index file
631   // was empty and we are not performing ThinLTO backend compilation (used in
632   // testing in a distributed build environment). Drop any the type test
633   // assume sequences inserted for whole program vtables so that codegen doesn't
634   // complain.
635   if (!CodeGenOpts.ThinLTOIndexFile.empty())
636     MPM.add(createLowerTypeTestsPass(/*ExportSummary=*/nullptr,
637                                      /*ImportSummary=*/nullptr,
638                                      /*DropTypeTests=*/true));
639 
640   PassManagerBuilderWrapper PMBuilder(TargetTriple, CodeGenOpts, LangOpts);
641 
642   // At O0 and O1 we only run the always inliner which is more efficient. At
643   // higher optimization levels we run the normal inliner.
644   if (CodeGenOpts.OptimizationLevel <= 1) {
645     bool InsertLifetimeIntrinsics = ((CodeGenOpts.OptimizationLevel != 0 &&
646                                       !CodeGenOpts.DisableLifetimeMarkers) ||
647                                      LangOpts.Coroutines);
648     PMBuilder.Inliner = createAlwaysInlinerLegacyPass(InsertLifetimeIntrinsics);
649   } else {
650     // We do not want to inline hot callsites for SamplePGO module-summary build
651     // because profile annotation will happen again in ThinLTO backend, and we
652     // want the IR of the hot path to match the profile.
653     PMBuilder.Inliner = createFunctionInliningPass(
654         CodeGenOpts.OptimizationLevel, CodeGenOpts.OptimizeSize,
655         (!CodeGenOpts.SampleProfileFile.empty() &&
656          CodeGenOpts.PrepareForThinLTO));
657   }
658 
659   PMBuilder.OptLevel = CodeGenOpts.OptimizationLevel;
660   PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
661   PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
662   PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
663   // Only enable CGProfilePass when using integrated assembler, since
664   // non-integrated assemblers don't recognize .cgprofile section.
665   PMBuilder.CallGraphProfile = !CodeGenOpts.DisableIntegratedAS;
666 
667   PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
668   // Loop interleaving in the loop vectorizer has historically been set to be
669   // enabled when loop unrolling is enabled.
670   PMBuilder.LoopsInterleaved = CodeGenOpts.UnrollLoops;
671   PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
672   PMBuilder.PrepareForThinLTO = CodeGenOpts.PrepareForThinLTO;
673   PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
674   PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
675 
676   MPM.add(new TargetLibraryInfoWrapperPass(*TLII));
677 
678   if (TM)
679     TM->adjustPassManager(PMBuilder);
680 
681   if (CodeGenOpts.DebugInfoForProfiling ||
682       !CodeGenOpts.SampleProfileFile.empty())
683     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
684                            addAddDiscriminatorsPass);
685 
686   // In ObjC ARC mode, add the main ARC optimization passes.
687   if (LangOpts.ObjCAutoRefCount) {
688     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
689                            addObjCARCExpandPass);
690     PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
691                            addObjCARCAPElimPass);
692     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
693                            addObjCARCOptPass);
694   }
695 
696   if (LangOpts.Coroutines)
697     addCoroutinePassesToExtensionPoints(PMBuilder);
698 
699   if (!CodeGenOpts.MemoryProfileOutput.empty()) {
700     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
701                            addMemProfilerPasses);
702     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
703                            addMemProfilerPasses);
704   }
705 
706   if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds)) {
707     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
708                            addBoundsCheckingPass);
709     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
710                            addBoundsCheckingPass);
711   }
712 
713   if (CodeGenOpts.SanitizeCoverageType ||
714       CodeGenOpts.SanitizeCoverageIndirectCalls ||
715       CodeGenOpts.SanitizeCoverageTraceCmp) {
716     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
717                            addSanitizerCoveragePass);
718     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
719                            addSanitizerCoveragePass);
720   }
721 
722   if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
723     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
724                            addAddressSanitizerPasses);
725     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
726                            addAddressSanitizerPasses);
727   }
728 
729   if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
730     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
731                            addKernelAddressSanitizerPasses);
732     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
733                            addKernelAddressSanitizerPasses);
734   }
735 
736   if (LangOpts.Sanitize.has(SanitizerKind::HWAddress)) {
737     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
738                            addHWAddressSanitizerPasses);
739     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
740                            addHWAddressSanitizerPasses);
741   }
742 
743   if (LangOpts.Sanitize.has(SanitizerKind::KernelHWAddress)) {
744     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
745                            addKernelHWAddressSanitizerPasses);
746     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
747                            addKernelHWAddressSanitizerPasses);
748   }
749 
750   if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
751     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
752                            addMemorySanitizerPass);
753     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
754                            addMemorySanitizerPass);
755   }
756 
757   if (LangOpts.Sanitize.has(SanitizerKind::KernelMemory)) {
758     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
759                            addKernelMemorySanitizerPass);
760     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
761                            addKernelMemorySanitizerPass);
762   }
763 
764   if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
765     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
766                            addThreadSanitizerPass);
767     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
768                            addThreadSanitizerPass);
769   }
770 
771   if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
772     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
773                            addDataFlowSanitizerPass);
774     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
775                            addDataFlowSanitizerPass);
776   }
777 
778   // Set up the per-function pass manager.
779   FPM.add(new TargetLibraryInfoWrapperPass(*TLII));
780   if (CodeGenOpts.VerifyModule)
781     FPM.add(createVerifierPass());
782 
783   // Set up the per-module pass manager.
784   if (!CodeGenOpts.RewriteMapFiles.empty())
785     addSymbolRewriterPass(CodeGenOpts, &MPM);
786 
787   // Add UniqueInternalLinkageNames Pass which renames internal linkage symbols
788   // with unique names.
789   if (CodeGenOpts.UniqueInternalLinkageNames) {
790     MPM.add(createUniqueInternalLinkageNamesPass());
791   }
792 
793   if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts, LangOpts)) {
794     MPM.add(createGCOVProfilerPass(*Options));
795     if (CodeGenOpts.getDebugInfo() == codegenoptions::NoDebugInfo)
796       MPM.add(createStripSymbolsPass(true));
797   }
798 
799   if (Optional<InstrProfOptions> Options =
800           getInstrProfOptions(CodeGenOpts, LangOpts))
801     MPM.add(createInstrProfilingLegacyPass(*Options, false));
802 
803   bool hasIRInstr = false;
804   if (CodeGenOpts.hasProfileIRInstr()) {
805     PMBuilder.EnablePGOInstrGen = true;
806     hasIRInstr = true;
807   }
808   if (CodeGenOpts.hasProfileCSIRInstr()) {
809     assert(!CodeGenOpts.hasProfileCSIRUse() &&
810            "Cannot have both CSProfileUse pass and CSProfileGen pass at the "
811            "same time");
812     assert(!hasIRInstr &&
813            "Cannot have both ProfileGen pass and CSProfileGen pass at the "
814            "same time");
815     PMBuilder.EnablePGOCSInstrGen = true;
816     hasIRInstr = true;
817   }
818   if (hasIRInstr) {
819     if (!CodeGenOpts.InstrProfileOutput.empty())
820       PMBuilder.PGOInstrGen = CodeGenOpts.InstrProfileOutput;
821     else
822       PMBuilder.PGOInstrGen = std::string(DefaultProfileGenName);
823   }
824   if (CodeGenOpts.hasProfileIRUse()) {
825     PMBuilder.PGOInstrUse = CodeGenOpts.ProfileInstrumentUsePath;
826     PMBuilder.EnablePGOCSInstrUse = CodeGenOpts.hasProfileCSIRUse();
827   }
828 
829   if (!CodeGenOpts.SampleProfileFile.empty())
830     PMBuilder.PGOSampleUse = CodeGenOpts.SampleProfileFile;
831 
832   PMBuilder.populateFunctionPassManager(FPM);
833   PMBuilder.populateModulePassManager(MPM);
834 }
835 
836 static void setCommandLineOpts(const CodeGenOptions &CodeGenOpts) {
837   SmallVector<const char *, 16> BackendArgs;
838   BackendArgs.push_back("clang"); // Fake program name.
839   if (!CodeGenOpts.DebugPass.empty()) {
840     BackendArgs.push_back("-debug-pass");
841     BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
842   }
843   if (!CodeGenOpts.LimitFloatPrecision.empty()) {
844     BackendArgs.push_back("-limit-float-precision");
845     BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
846   }
847   BackendArgs.push_back(nullptr);
848   llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
849                                     BackendArgs.data());
850 }
851 
852 void EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
853   // Create the TargetMachine for generating code.
854   std::string Error;
855   std::string Triple = TheModule->getTargetTriple();
856   const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
857   if (!TheTarget) {
858     if (MustCreateTM)
859       Diags.Report(diag::err_fe_unable_to_create_target) << Error;
860     return;
861   }
862 
863   Optional<llvm::CodeModel::Model> CM = getCodeModel(CodeGenOpts);
864   std::string FeaturesStr =
865       llvm::join(TargetOpts.Features.begin(), TargetOpts.Features.end(), ",");
866   llvm::Reloc::Model RM = CodeGenOpts.RelocationModel;
867   CodeGenOpt::Level OptLevel = getCGOptLevel(CodeGenOpts);
868 
869   llvm::TargetOptions Options;
870   if (!initTargetOptions(Diags, Options, CodeGenOpts, TargetOpts, LangOpts,
871                          HSOpts))
872     return;
873   TM.reset(TheTarget->createTargetMachine(Triple, TargetOpts.CPU, FeaturesStr,
874                                           Options, RM, CM, OptLevel));
875 }
876 
877 bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
878                                        BackendAction Action,
879                                        raw_pwrite_stream &OS,
880                                        raw_pwrite_stream *DwoOS) {
881   // Add LibraryInfo.
882   llvm::Triple TargetTriple(TheModule->getTargetTriple());
883   std::unique_ptr<TargetLibraryInfoImpl> TLII(
884       createTLII(TargetTriple, CodeGenOpts));
885   CodeGenPasses.add(new TargetLibraryInfoWrapperPass(*TLII));
886 
887   // Normal mode, emit a .s or .o file by running the code generator. Note,
888   // this also adds codegenerator level optimization passes.
889   CodeGenFileType CGFT = getCodeGenFileType(Action);
890 
891   // Add ObjC ARC final-cleanup optimizations. This is done as part of the
892   // "codegen" passes so that it isn't run multiple times when there is
893   // inlining happening.
894   if (CodeGenOpts.OptimizationLevel > 0)
895     CodeGenPasses.add(createObjCARCContractPass());
896 
897   if (TM->addPassesToEmitFile(CodeGenPasses, OS, DwoOS, CGFT,
898                               /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
899     Diags.Report(diag::err_fe_unable_to_interface_with_target);
900     return false;
901   }
902 
903   return true;
904 }
905 
906 void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
907                                       std::unique_ptr<raw_pwrite_stream> OS) {
908   TimeRegion Region(FrontendTimesIsEnabled ? &CodeGenerationTime : nullptr);
909 
910   setCommandLineOpts(CodeGenOpts);
911 
912   bool UsesCodeGen = (Action != Backend_EmitNothing &&
913                       Action != Backend_EmitBC &&
914                       Action != Backend_EmitLL);
915   CreateTargetMachine(UsesCodeGen);
916 
917   if (UsesCodeGen && !TM)
918     return;
919   if (TM)
920     TheModule->setDataLayout(TM->createDataLayout());
921 
922   legacy::PassManager PerModulePasses;
923   PerModulePasses.add(
924       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
925 
926   legacy::FunctionPassManager PerFunctionPasses(TheModule);
927   PerFunctionPasses.add(
928       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
929 
930   CreatePasses(PerModulePasses, PerFunctionPasses);
931 
932   legacy::PassManager CodeGenPasses;
933   CodeGenPasses.add(
934       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
935 
936   std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
937 
938   switch (Action) {
939   case Backend_EmitNothing:
940     break;
941 
942   case Backend_EmitBC:
943     if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
944       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
945         ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
946         if (!ThinLinkOS)
947           return;
948       }
949       TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
950                                CodeGenOpts.EnableSplitLTOUnit);
951       PerModulePasses.add(createWriteThinLTOBitcodePass(
952           *OS, ThinLinkOS ? &ThinLinkOS->os() : nullptr));
953     } else {
954       // Emit a module summary by default for Regular LTO except for ld64
955       // targets
956       bool EmitLTOSummary =
957           (CodeGenOpts.PrepareForLTO &&
958            !CodeGenOpts.DisableLLVMPasses &&
959            llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
960                llvm::Triple::Apple);
961       if (EmitLTOSummary) {
962         if (!TheModule->getModuleFlag("ThinLTO"))
963           TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
964         TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
965                                  uint32_t(1));
966       }
967 
968       PerModulePasses.add(createBitcodeWriterPass(
969           *OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
970     }
971     break;
972 
973   case Backend_EmitLL:
974     PerModulePasses.add(
975         createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
976     break;
977 
978   default:
979     if (!CodeGenOpts.SplitDwarfOutput.empty()) {
980       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
981       if (!DwoOS)
982         return;
983     }
984     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
985                        DwoOS ? &DwoOS->os() : nullptr))
986       return;
987   }
988 
989   // Before executing passes, print the final values of the LLVM options.
990   cl::PrintOptionValues();
991 
992   // Run passes. For now we do all passes at once, but eventually we
993   // would like to have the option of streaming code generation.
994 
995   {
996     PrettyStackTraceString CrashInfo("Per-function optimization");
997     llvm::TimeTraceScope TimeScope("PerFunctionPasses");
998 
999     PerFunctionPasses.doInitialization();
1000     for (Function &F : *TheModule)
1001       if (!F.isDeclaration())
1002         PerFunctionPasses.run(F);
1003     PerFunctionPasses.doFinalization();
1004   }
1005 
1006   {
1007     PrettyStackTraceString CrashInfo("Per-module optimization passes");
1008     llvm::TimeTraceScope TimeScope("PerModulePasses");
1009     PerModulePasses.run(*TheModule);
1010   }
1011 
1012   {
1013     PrettyStackTraceString CrashInfo("Code generation");
1014     llvm::TimeTraceScope TimeScope("CodeGenPasses");
1015     CodeGenPasses.run(*TheModule);
1016   }
1017 
1018   if (ThinLinkOS)
1019     ThinLinkOS->keep();
1020   if (DwoOS)
1021     DwoOS->keep();
1022 }
1023 
1024 static PassBuilder::OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
1025   switch (Opts.OptimizationLevel) {
1026   default:
1027     llvm_unreachable("Invalid optimization level!");
1028 
1029   case 0:
1030     return PassBuilder::OptimizationLevel::O0;
1031 
1032   case 1:
1033     return PassBuilder::OptimizationLevel::O1;
1034 
1035   case 2:
1036     switch (Opts.OptimizeSize) {
1037     default:
1038       llvm_unreachable("Invalid optimization level for size!");
1039 
1040     case 0:
1041       return PassBuilder::OptimizationLevel::O2;
1042 
1043     case 1:
1044       return PassBuilder::OptimizationLevel::Os;
1045 
1046     case 2:
1047       return PassBuilder::OptimizationLevel::Oz;
1048     }
1049 
1050   case 3:
1051     return PassBuilder::OptimizationLevel::O3;
1052   }
1053 }
1054 
1055 /// A clean version of `EmitAssembly` that uses the new pass manager.
1056 ///
1057 /// Not all features are currently supported in this system, but where
1058 /// necessary it falls back to the legacy pass manager to at least provide
1059 /// basic functionality.
1060 ///
1061 /// This API is planned to have its functionality finished and then to replace
1062 /// `EmitAssembly` at some point in the future when the default switches.
1063 void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
1064     BackendAction Action, std::unique_ptr<raw_pwrite_stream> OS) {
1065   TimeRegion Region(FrontendTimesIsEnabled ? &CodeGenerationTime : nullptr);
1066   setCommandLineOpts(CodeGenOpts);
1067 
1068   bool RequiresCodeGen = (Action != Backend_EmitNothing &&
1069                           Action != Backend_EmitBC &&
1070                           Action != Backend_EmitLL);
1071   CreateTargetMachine(RequiresCodeGen);
1072 
1073   if (RequiresCodeGen && !TM)
1074     return;
1075   if (TM)
1076     TheModule->setDataLayout(TM->createDataLayout());
1077 
1078   Optional<PGOOptions> PGOOpt;
1079 
1080   if (CodeGenOpts.hasProfileIRInstr())
1081     // -fprofile-generate.
1082     PGOOpt = PGOOptions(CodeGenOpts.InstrProfileOutput.empty()
1083                             ? std::string(DefaultProfileGenName)
1084                             : CodeGenOpts.InstrProfileOutput,
1085                         "", "", PGOOptions::IRInstr, PGOOptions::NoCSAction,
1086                         CodeGenOpts.DebugInfoForProfiling);
1087   else if (CodeGenOpts.hasProfileIRUse()) {
1088     // -fprofile-use.
1089     auto CSAction = CodeGenOpts.hasProfileCSIRUse() ? PGOOptions::CSIRUse
1090                                                     : PGOOptions::NoCSAction;
1091     PGOOpt = PGOOptions(CodeGenOpts.ProfileInstrumentUsePath, "",
1092                         CodeGenOpts.ProfileRemappingFile, PGOOptions::IRUse,
1093                         CSAction, CodeGenOpts.DebugInfoForProfiling);
1094   } else if (!CodeGenOpts.SampleProfileFile.empty())
1095     // -fprofile-sample-use
1096     PGOOpt =
1097         PGOOptions(CodeGenOpts.SampleProfileFile, "",
1098                    CodeGenOpts.ProfileRemappingFile, PGOOptions::SampleUse,
1099                    PGOOptions::NoCSAction, CodeGenOpts.DebugInfoForProfiling);
1100   else if (CodeGenOpts.DebugInfoForProfiling)
1101     // -fdebug-info-for-profiling
1102     PGOOpt = PGOOptions("", "", "", PGOOptions::NoAction,
1103                         PGOOptions::NoCSAction, true);
1104 
1105   // Check to see if we want to generate a CS profile.
1106   if (CodeGenOpts.hasProfileCSIRInstr()) {
1107     assert(!CodeGenOpts.hasProfileCSIRUse() &&
1108            "Cannot have both CSProfileUse pass and CSProfileGen pass at "
1109            "the same time");
1110     if (PGOOpt.hasValue()) {
1111       assert(PGOOpt->Action != PGOOptions::IRInstr &&
1112              PGOOpt->Action != PGOOptions::SampleUse &&
1113              "Cannot run CSProfileGen pass with ProfileGen or SampleUse "
1114              " pass");
1115       PGOOpt->CSProfileGenFile = CodeGenOpts.InstrProfileOutput.empty()
1116                                      ? std::string(DefaultProfileGenName)
1117                                      : CodeGenOpts.InstrProfileOutput;
1118       PGOOpt->CSAction = PGOOptions::CSIRInstr;
1119     } else
1120       PGOOpt = PGOOptions("",
1121                           CodeGenOpts.InstrProfileOutput.empty()
1122                               ? std::string(DefaultProfileGenName)
1123                               : CodeGenOpts.InstrProfileOutput,
1124                           "", PGOOptions::NoAction, PGOOptions::CSIRInstr,
1125                           CodeGenOpts.DebugInfoForProfiling);
1126   }
1127 
1128   PipelineTuningOptions PTO;
1129   PTO.LoopUnrolling = CodeGenOpts.UnrollLoops;
1130   // For historical reasons, loop interleaving is set to mirror setting for loop
1131   // unrolling.
1132   PTO.LoopInterleaving = CodeGenOpts.UnrollLoops;
1133   PTO.LoopVectorization = CodeGenOpts.VectorizeLoop;
1134   PTO.SLPVectorization = CodeGenOpts.VectorizeSLP;
1135   // Only enable CGProfilePass when using integrated assembler, since
1136   // non-integrated assemblers don't recognize .cgprofile section.
1137   PTO.CallGraphProfile = !CodeGenOpts.DisableIntegratedAS;
1138   PTO.Coroutines = LangOpts.Coroutines;
1139 
1140   PassInstrumentationCallbacks PIC;
1141   StandardInstrumentations SI(CodeGenOpts.DebugPassManager);
1142   SI.registerCallbacks(PIC);
1143   PassBuilder PB(CodeGenOpts.DebugPassManager, TM.get(), PTO, PGOOpt, &PIC);
1144 
1145   // Attempt to load pass plugins and register their callbacks with PB.
1146   for (auto &PluginFN : CodeGenOpts.PassPlugins) {
1147     auto PassPlugin = PassPlugin::Load(PluginFN);
1148     if (PassPlugin) {
1149       PassPlugin->registerPassBuilderCallbacks(PB);
1150     } else {
1151       Diags.Report(diag::err_fe_unable_to_load_plugin)
1152           << PluginFN << toString(PassPlugin.takeError());
1153     }
1154   }
1155 #define HANDLE_EXTENSION(Ext)                                                  \
1156   get##Ext##PluginInfo().RegisterPassBuilderCallbacks(PB);
1157 #include "llvm/Support/Extension.def"
1158 
1159   LoopAnalysisManager LAM(CodeGenOpts.DebugPassManager);
1160   FunctionAnalysisManager FAM(CodeGenOpts.DebugPassManager);
1161   CGSCCAnalysisManager CGAM(CodeGenOpts.DebugPassManager);
1162   ModuleAnalysisManager MAM(CodeGenOpts.DebugPassManager);
1163 
1164   // Register the AA manager first so that our version is the one used.
1165   FAM.registerPass([&] { return PB.buildDefaultAAPipeline(); });
1166 
1167   // Register the target library analysis directly and give it a customized
1168   // preset TLI.
1169   Triple TargetTriple(TheModule->getTargetTriple());
1170   std::unique_ptr<TargetLibraryInfoImpl> TLII(
1171       createTLII(TargetTriple, CodeGenOpts));
1172   FAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); });
1173 
1174   // Register all the basic analyses with the managers.
1175   PB.registerModuleAnalyses(MAM);
1176   PB.registerCGSCCAnalyses(CGAM);
1177   PB.registerFunctionAnalyses(FAM);
1178   PB.registerLoopAnalyses(LAM);
1179   PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
1180 
1181   ModulePassManager MPM(CodeGenOpts.DebugPassManager);
1182 
1183   if (!CodeGenOpts.DisableLLVMPasses) {
1184     // Map our optimization levels into one of the distinct levels used to
1185     // configure the pipeline.
1186     PassBuilder::OptimizationLevel Level = mapToLevel(CodeGenOpts);
1187 
1188     bool IsThinLTO = CodeGenOpts.PrepareForThinLTO;
1189     bool IsLTO = CodeGenOpts.PrepareForLTO;
1190 
1191     // If we reached here with a non-empty index file name, then the index
1192     // file was empty and we are not performing ThinLTO backend compilation
1193     // (used in testing in a distributed build environment). Drop any the type
1194     // test assume sequences inserted for whole program vtables so that
1195     // codegen doesn't complain.
1196     if (!CodeGenOpts.ThinLTOIndexFile.empty())
1197       PB.registerPipelineStartEPCallback(
1198           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1199             MPM.addPass(LowerTypeTestsPass(/*ExportSummary=*/nullptr,
1200                                            /*ImportSummary=*/nullptr,
1201                                            /*DropTypeTests=*/true));
1202           });
1203 
1204     if (Level != PassBuilder::OptimizationLevel::O0) {
1205       PB.registerPipelineStartEPCallback(
1206           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1207             MPM.addPass(createModuleToFunctionPassAdaptor(
1208                 EntryExitInstrumenterPass(/*PostInlining=*/false)));
1209           });
1210     }
1211 
1212     // Register callbacks to schedule sanitizer passes at the appropriate part
1213     // of the pipeline.
1214     if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
1215       PB.registerScalarOptimizerLateEPCallback(
1216           [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
1217             FPM.addPass(BoundsCheckingPass());
1218           });
1219 
1220     if (CodeGenOpts.SanitizeCoverageType ||
1221         CodeGenOpts.SanitizeCoverageIndirectCalls ||
1222         CodeGenOpts.SanitizeCoverageTraceCmp) {
1223       PB.registerOptimizerLastEPCallback(
1224           [this](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1225             auto SancovOpts = getSancovOptsFromCGOpts(CodeGenOpts);
1226             MPM.addPass(ModuleSanitizerCoveragePass(
1227                 SancovOpts, CodeGenOpts.SanitizeCoverageAllowlistFiles,
1228                 CodeGenOpts.SanitizeCoverageBlocklistFiles));
1229           });
1230     }
1231 
1232     if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
1233       int TrackOrigins = CodeGenOpts.SanitizeMemoryTrackOrigins;
1234       bool Recover = CodeGenOpts.SanitizeRecover.has(SanitizerKind::Memory);
1235       PB.registerOptimizerLastEPCallback(
1236           [TrackOrigins, Recover](ModulePassManager &MPM,
1237                                   PassBuilder::OptimizationLevel Level) {
1238             MPM.addPass(MemorySanitizerPass({TrackOrigins, Recover, false}));
1239             MPM.addPass(createModuleToFunctionPassAdaptor(
1240                 MemorySanitizerPass({TrackOrigins, Recover, false})));
1241           });
1242     }
1243     if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
1244       PB.registerOptimizerLastEPCallback(
1245           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1246             MPM.addPass(ThreadSanitizerPass());
1247             MPM.addPass(
1248                 createModuleToFunctionPassAdaptor(ThreadSanitizerPass()));
1249           });
1250     }
1251 
1252     auto ASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
1253       if (LangOpts.Sanitize.has(Mask)) {
1254         bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
1255         bool UseAfterScope = CodeGenOpts.SanitizeAddressUseAfterScope;
1256         bool ModuleUseAfterScope = asanUseGlobalsGC(TargetTriple, CodeGenOpts);
1257         bool UseOdrIndicator = CodeGenOpts.SanitizeAddressUseOdrIndicator;
1258         PB.registerOptimizerLastEPCallback(
1259             [CompileKernel, Recover, UseAfterScope, ModuleUseAfterScope,
1260              UseOdrIndicator](ModulePassManager &MPM,
1261                               PassBuilder::OptimizationLevel Level) {
1262               MPM.addPass(
1263                   RequireAnalysisPass<ASanGlobalsMetadataAnalysis, Module>());
1264               MPM.addPass(ModuleAddressSanitizerPass(CompileKernel, Recover,
1265                                                      ModuleUseAfterScope,
1266                                                      UseOdrIndicator));
1267               MPM.addPass(createModuleToFunctionPassAdaptor(
1268                   AddressSanitizerPass(CompileKernel, Recover, UseAfterScope)));
1269             });
1270       }
1271     };
1272     ASanPass(SanitizerKind::Address, false);
1273     ASanPass(SanitizerKind::KernelAddress, true);
1274 
1275     auto HWASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
1276       if (LangOpts.Sanitize.has(Mask)) {
1277         bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
1278         PB.registerOptimizerLastEPCallback(
1279             [CompileKernel, Recover](ModulePassManager &MPM,
1280                                      PassBuilder::OptimizationLevel Level) {
1281               MPM.addPass(HWAddressSanitizerPass(CompileKernel, Recover));
1282             });
1283       }
1284     };
1285     HWASanPass(SanitizerKind::HWAddress, false);
1286     HWASanPass(SanitizerKind::KernelHWAddress, true);
1287 
1288     if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
1289       PB.registerOptimizerLastEPCallback(
1290           [this](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1291             MPM.addPass(
1292                 DataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
1293           });
1294     }
1295 
1296     if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts, LangOpts))
1297       PB.registerPipelineStartEPCallback(
1298           [Options](ModulePassManager &MPM,
1299                     PassBuilder::OptimizationLevel Level) {
1300             MPM.addPass(GCOVProfilerPass(*Options));
1301           });
1302     if (Optional<InstrProfOptions> Options =
1303             getInstrProfOptions(CodeGenOpts, LangOpts))
1304       PB.registerPipelineStartEPCallback(
1305           [Options](ModulePassManager &MPM,
1306                     PassBuilder::OptimizationLevel Level) {
1307             MPM.addPass(InstrProfiling(*Options, false));
1308           });
1309 
1310     if (CodeGenOpts.OptimizationLevel == 0) {
1311       MPM = PB.buildO0DefaultPipeline(Level, IsLTO || IsThinLTO);
1312     } else if (IsThinLTO) {
1313       MPM = PB.buildThinLTOPreLinkDefaultPipeline(Level);
1314     } else if (IsLTO) {
1315       MPM = PB.buildLTOPreLinkDefaultPipeline(Level);
1316     } else {
1317       MPM = PB.buildPerModuleDefaultPipeline(Level);
1318     }
1319 
1320     // Add UniqueInternalLinkageNames Pass which renames internal linkage
1321     // symbols with unique names.
1322     if (CodeGenOpts.UniqueInternalLinkageNames)
1323       MPM.addPass(UniqueInternalLinkageNamesPass());
1324 
1325     if (!CodeGenOpts.MemoryProfileOutput.empty()) {
1326       MPM.addPass(createModuleToFunctionPassAdaptor(MemProfilerPass()));
1327       MPM.addPass(ModuleMemProfilerPass());
1328     }
1329   }
1330 
1331   // FIXME: We still use the legacy pass manager to do code generation. We
1332   // create that pass manager here and use it as needed below.
1333   legacy::PassManager CodeGenPasses;
1334   bool NeedCodeGen = false;
1335   std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
1336 
1337   // Append any output we need to the pass manager.
1338   switch (Action) {
1339   case Backend_EmitNothing:
1340     break;
1341 
1342   case Backend_EmitBC:
1343     if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
1344       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
1345         ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
1346         if (!ThinLinkOS)
1347           return;
1348       }
1349       TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1350                                CodeGenOpts.EnableSplitLTOUnit);
1351       MPM.addPass(ThinLTOBitcodeWriterPass(*OS, ThinLinkOS ? &ThinLinkOS->os()
1352                                                            : nullptr));
1353     } else {
1354       // Emit a module summary by default for Regular LTO except for ld64
1355       // targets
1356       bool EmitLTOSummary =
1357           (CodeGenOpts.PrepareForLTO &&
1358            !CodeGenOpts.DisableLLVMPasses &&
1359            llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
1360                llvm::Triple::Apple);
1361       if (EmitLTOSummary) {
1362         if (!TheModule->getModuleFlag("ThinLTO"))
1363           TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
1364         TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1365                                  uint32_t(1));
1366       }
1367       MPM.addPass(
1368           BitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
1369     }
1370     break;
1371 
1372   case Backend_EmitLL:
1373     MPM.addPass(PrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
1374     break;
1375 
1376   case Backend_EmitAssembly:
1377   case Backend_EmitMCNull:
1378   case Backend_EmitObj:
1379     NeedCodeGen = true;
1380     CodeGenPasses.add(
1381         createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
1382     if (!CodeGenOpts.SplitDwarfOutput.empty()) {
1383       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
1384       if (!DwoOS)
1385         return;
1386     }
1387     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
1388                        DwoOS ? &DwoOS->os() : nullptr))
1389       // FIXME: Should we handle this error differently?
1390       return;
1391     break;
1392   }
1393 
1394   // Before executing passes, print the final values of the LLVM options.
1395   cl::PrintOptionValues();
1396 
1397   // Now that we have all of the passes ready, run them.
1398   {
1399     PrettyStackTraceString CrashInfo("Optimizer");
1400     MPM.run(*TheModule, MAM);
1401   }
1402 
1403   // Now if needed, run the legacy PM for codegen.
1404   if (NeedCodeGen) {
1405     PrettyStackTraceString CrashInfo("Code generation");
1406     CodeGenPasses.run(*TheModule);
1407   }
1408 
1409   if (ThinLinkOS)
1410     ThinLinkOS->keep();
1411   if (DwoOS)
1412     DwoOS->keep();
1413 }
1414 
1415 static void runThinLTOBackend(
1416     DiagnosticsEngine &Diags, ModuleSummaryIndex *CombinedIndex, Module *M,
1417     const HeaderSearchOptions &HeaderOpts, const CodeGenOptions &CGOpts,
1418     const clang::TargetOptions &TOpts, const LangOptions &LOpts,
1419     std::unique_ptr<raw_pwrite_stream> OS, std::string SampleProfile,
1420     std::string ProfileRemapping, BackendAction Action) {
1421   StringMap<DenseMap<GlobalValue::GUID, GlobalValueSummary *>>
1422       ModuleToDefinedGVSummaries;
1423   CombinedIndex->collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries);
1424 
1425   setCommandLineOpts(CGOpts);
1426 
1427   // We can simply import the values mentioned in the combined index, since
1428   // we should only invoke this using the individual indexes written out
1429   // via a WriteIndexesThinBackend.
1430   FunctionImporter::ImportMapTy ImportList;
1431   std::vector<std::unique_ptr<llvm::MemoryBuffer>> OwnedImports;
1432   MapVector<llvm::StringRef, llvm::BitcodeModule> ModuleMap;
1433   if (!lto::loadReferencedModules(*M, *CombinedIndex, ImportList, ModuleMap,
1434                                   OwnedImports))
1435     return;
1436 
1437   auto AddStream = [&](size_t Task) {
1438     return std::make_unique<lto::NativeObjectStream>(std::move(OS));
1439   };
1440   lto::Config Conf;
1441   if (CGOpts.SaveTempsFilePrefix != "") {
1442     if (Error E = Conf.addSaveTemps(CGOpts.SaveTempsFilePrefix + ".",
1443                                     /* UseInputModulePath */ false)) {
1444       handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1445         errs() << "Error setting up ThinLTO save-temps: " << EIB.message()
1446                << '\n';
1447       });
1448     }
1449   }
1450   Conf.CPU = TOpts.CPU;
1451   Conf.CodeModel = getCodeModel(CGOpts);
1452   Conf.MAttrs = TOpts.Features;
1453   Conf.RelocModel = CGOpts.RelocationModel;
1454   Conf.CGOptLevel = getCGOptLevel(CGOpts);
1455   Conf.OptLevel = CGOpts.OptimizationLevel;
1456   initTargetOptions(Diags, Conf.Options, CGOpts, TOpts, LOpts, HeaderOpts);
1457   Conf.SampleProfile = std::move(SampleProfile);
1458   Conf.PTO.LoopUnrolling = CGOpts.UnrollLoops;
1459   // For historical reasons, loop interleaving is set to mirror setting for loop
1460   // unrolling.
1461   Conf.PTO.LoopInterleaving = CGOpts.UnrollLoops;
1462   Conf.PTO.LoopVectorization = CGOpts.VectorizeLoop;
1463   Conf.PTO.SLPVectorization = CGOpts.VectorizeSLP;
1464   // Only enable CGProfilePass when using integrated assembler, since
1465   // non-integrated assemblers don't recognize .cgprofile section.
1466   Conf.PTO.CallGraphProfile = !CGOpts.DisableIntegratedAS;
1467 
1468   // Context sensitive profile.
1469   if (CGOpts.hasProfileCSIRInstr()) {
1470     Conf.RunCSIRInstr = true;
1471     Conf.CSIRProfile = std::move(CGOpts.InstrProfileOutput);
1472   } else if (CGOpts.hasProfileCSIRUse()) {
1473     Conf.RunCSIRInstr = false;
1474     Conf.CSIRProfile = std::move(CGOpts.ProfileInstrumentUsePath);
1475   }
1476 
1477   Conf.ProfileRemapping = std::move(ProfileRemapping);
1478   Conf.UseNewPM = CGOpts.ExperimentalNewPassManager;
1479   Conf.DebugPassManager = CGOpts.DebugPassManager;
1480   Conf.RemarksWithHotness = CGOpts.DiagnosticsWithHotness;
1481   Conf.RemarksFilename = CGOpts.OptRecordFile;
1482   Conf.RemarksPasses = CGOpts.OptRecordPasses;
1483   Conf.RemarksFormat = CGOpts.OptRecordFormat;
1484   Conf.SplitDwarfFile = CGOpts.SplitDwarfFile;
1485   Conf.SplitDwarfOutput = CGOpts.SplitDwarfOutput;
1486   switch (Action) {
1487   case Backend_EmitNothing:
1488     Conf.PreCodeGenModuleHook = [](size_t Task, const Module &Mod) {
1489       return false;
1490     };
1491     break;
1492   case Backend_EmitLL:
1493     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1494       M->print(*OS, nullptr, CGOpts.EmitLLVMUseLists);
1495       return false;
1496     };
1497     break;
1498   case Backend_EmitBC:
1499     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1500       WriteBitcodeToFile(*M, *OS, CGOpts.EmitLLVMUseLists);
1501       return false;
1502     };
1503     break;
1504   default:
1505     Conf.CGFileType = getCodeGenFileType(Action);
1506     break;
1507   }
1508   if (Error E =
1509           thinBackend(Conf, -1, AddStream, *M, *CombinedIndex, ImportList,
1510                       ModuleToDefinedGVSummaries[M->getModuleIdentifier()],
1511                       ModuleMap, CGOpts.CmdArgs)) {
1512     handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1513       errs() << "Error running ThinLTO backend: " << EIB.message() << '\n';
1514     });
1515   }
1516 }
1517 
1518 void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
1519                               const HeaderSearchOptions &HeaderOpts,
1520                               const CodeGenOptions &CGOpts,
1521                               const clang::TargetOptions &TOpts,
1522                               const LangOptions &LOpts,
1523                               const llvm::DataLayout &TDesc, Module *M,
1524                               BackendAction Action,
1525                               std::unique_ptr<raw_pwrite_stream> OS) {
1526 
1527   llvm::TimeTraceScope TimeScope("Backend");
1528 
1529   std::unique_ptr<llvm::Module> EmptyModule;
1530   if (!CGOpts.ThinLTOIndexFile.empty()) {
1531     // If we are performing a ThinLTO importing compile, load the function index
1532     // into memory and pass it into runThinLTOBackend, which will run the
1533     // function importer and invoke LTO passes.
1534     Expected<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
1535         llvm::getModuleSummaryIndexForFile(CGOpts.ThinLTOIndexFile,
1536                                            /*IgnoreEmptyThinLTOIndexFile*/true);
1537     if (!IndexOrErr) {
1538       logAllUnhandledErrors(IndexOrErr.takeError(), errs(),
1539                             "Error loading index file '" +
1540                             CGOpts.ThinLTOIndexFile + "': ");
1541       return;
1542     }
1543     std::unique_ptr<ModuleSummaryIndex> CombinedIndex = std::move(*IndexOrErr);
1544     // A null CombinedIndex means we should skip ThinLTO compilation
1545     // (LLVM will optionally ignore empty index files, returning null instead
1546     // of an error).
1547     if (CombinedIndex) {
1548       if (!CombinedIndex->skipModuleByDistributedBackend()) {
1549         runThinLTOBackend(Diags, CombinedIndex.get(), M, HeaderOpts, CGOpts,
1550                           TOpts, LOpts, std::move(OS), CGOpts.SampleProfileFile,
1551                           CGOpts.ProfileRemappingFile, Action);
1552         return;
1553       }
1554       // Distributed indexing detected that nothing from the module is needed
1555       // for the final linking. So we can skip the compilation. We sill need to
1556       // output an empty object file to make sure that a linker does not fail
1557       // trying to read it. Also for some features, like CFI, we must skip
1558       // the compilation as CombinedIndex does not contain all required
1559       // information.
1560       EmptyModule = std::make_unique<llvm::Module>("empty", M->getContext());
1561       EmptyModule->setTargetTriple(M->getTargetTriple());
1562       M = EmptyModule.get();
1563     }
1564   }
1565 
1566   EmitAssemblyHelper AsmHelper(Diags, HeaderOpts, CGOpts, TOpts, LOpts, M);
1567 
1568   if (CGOpts.ExperimentalNewPassManager)
1569     AsmHelper.EmitAssemblyWithNewPassManager(Action, std::move(OS));
1570   else
1571     AsmHelper.EmitAssembly(Action, std::move(OS));
1572 
1573   // Verify clang's TargetInfo DataLayout against the LLVM TargetMachine's
1574   // DataLayout.
1575   if (AsmHelper.TM) {
1576     std::string DLDesc = M->getDataLayout().getStringRepresentation();
1577     if (DLDesc != TDesc.getStringRepresentation()) {
1578       unsigned DiagID = Diags.getCustomDiagID(
1579           DiagnosticsEngine::Error, "backend data layout '%0' does not match "
1580                                     "expected target description '%1'");
1581       Diags.Report(DiagID) << DLDesc << TDesc.getStringRepresentation();
1582     }
1583   }
1584 }
1585 
1586 // With -fembed-bitcode, save a copy of the llvm IR as data in the
1587 // __LLVM,__bitcode section.
1588 void clang::EmbedBitcode(llvm::Module *M, const CodeGenOptions &CGOpts,
1589                          llvm::MemoryBufferRef Buf) {
1590   if (CGOpts.getEmbedBitcode() == CodeGenOptions::Embed_Off)
1591     return;
1592   llvm::EmbedBitcodeInModule(
1593       *M, Buf, CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Marker,
1594       CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Bitcode,
1595       CGOpts.CmdArgs);
1596 }
1597