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   Options.ThreadModel =
457       llvm::StringSwitch<llvm::ThreadModel::Model>(CodeGenOpts.ThreadModel)
458           .Case("posix", llvm::ThreadModel::POSIX)
459           .Case("single", llvm::ThreadModel::Single);
460 
461   // Set float ABI type.
462   assert((CodeGenOpts.FloatABI == "soft" || CodeGenOpts.FloatABI == "softfp" ||
463           CodeGenOpts.FloatABI == "hard" || CodeGenOpts.FloatABI.empty()) &&
464          "Invalid Floating Point ABI!");
465   Options.FloatABIType =
466       llvm::StringSwitch<llvm::FloatABI::ABIType>(CodeGenOpts.FloatABI)
467           .Case("soft", llvm::FloatABI::Soft)
468           .Case("softfp", llvm::FloatABI::Soft)
469           .Case("hard", llvm::FloatABI::Hard)
470           .Default(llvm::FloatABI::Default);
471 
472   // Set FP fusion mode.
473   switch (LangOpts.getDefaultFPContractMode()) {
474   case LangOptions::FPM_Off:
475     // Preserve any contraction performed by the front-end.  (Strict performs
476     // splitting of the muladd intrinsic in the backend.)
477     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
478     break;
479   case LangOptions::FPM_On:
480     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
481     break;
482   case LangOptions::FPM_Fast:
483     Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
484     break;
485   }
486 
487   Options.UseInitArray = CodeGenOpts.UseInitArray;
488   Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
489   Options.CompressDebugSections = CodeGenOpts.getCompressDebugSections();
490   Options.RelaxELFRelocations = CodeGenOpts.RelaxELFRelocations;
491 
492   // Set EABI version.
493   Options.EABIVersion = TargetOpts.EABIVersion;
494 
495   if (LangOpts.SjLjExceptions)
496     Options.ExceptionModel = llvm::ExceptionHandling::SjLj;
497   if (LangOpts.SEHExceptions)
498     Options.ExceptionModel = llvm::ExceptionHandling::WinEH;
499   if (LangOpts.DWARFExceptions)
500     Options.ExceptionModel = llvm::ExceptionHandling::DwarfCFI;
501   if (LangOpts.WasmExceptions)
502     Options.ExceptionModel = llvm::ExceptionHandling::Wasm;
503 
504   Options.NoInfsFPMath = LangOpts.NoHonorInfs;
505   Options.NoNaNsFPMath = LangOpts.NoHonorNaNs;
506   Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
507   Options.UnsafeFPMath = LangOpts.UnsafeFPMath;
508   Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
509 
510   Options.BBSections =
511       llvm::StringSwitch<llvm::BasicBlockSection>(CodeGenOpts.BBSections)
512           .Case("all", llvm::BasicBlockSection::All)
513           .Case("labels", llvm::BasicBlockSection::Labels)
514           .StartsWith("list=", llvm::BasicBlockSection::List)
515           .Case("none", llvm::BasicBlockSection::None)
516           .Default(llvm::BasicBlockSection::None);
517 
518   if (Options.BBSections == llvm::BasicBlockSection::List) {
519     ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
520         MemoryBuffer::getFile(CodeGenOpts.BBSections.substr(5));
521     if (!MBOrErr) {
522       Diags.Report(diag::err_fe_unable_to_load_basic_block_sections_file)
523           << MBOrErr.getError().message();
524       return false;
525     }
526     Options.BBSectionsFuncListBuf = std::move(*MBOrErr);
527   }
528 
529   Options.EnableMachineFunctionSplitter = CodeGenOpts.SplitMachineFunctions;
530   Options.FunctionSections = CodeGenOpts.FunctionSections;
531   Options.DataSections = CodeGenOpts.DataSections;
532   Options.IgnoreXCOFFVisibility = CodeGenOpts.IgnoreXCOFFVisibility;
533   Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
534   Options.UniqueBasicBlockSectionNames =
535       CodeGenOpts.UniqueBasicBlockSectionNames;
536   Options.StackProtectorGuard =
537       llvm::StringSwitch<llvm::StackProtectorGuards>(CodeGenOpts
538           .StackProtectorGuard)
539           .Case("tls", llvm::StackProtectorGuards::TLS)
540           .Case("global", llvm::StackProtectorGuards::Global)
541           .Default(llvm::StackProtectorGuards::None);
542   Options.StackProtectorGuardOffset = CodeGenOpts.StackProtectorGuardOffset;
543   Options.StackProtectorGuardReg = CodeGenOpts.StackProtectorGuardReg;
544   Options.TLSSize = CodeGenOpts.TLSSize;
545   Options.EmulatedTLS = CodeGenOpts.EmulatedTLS;
546   Options.ExplicitEmulatedTLS = CodeGenOpts.ExplicitEmulatedTLS;
547   Options.DebuggerTuning = CodeGenOpts.getDebuggerTuning();
548   Options.EmitStackSizeSection = CodeGenOpts.StackSizeSection;
549   Options.EmitAddrsig = CodeGenOpts.Addrsig;
550   Options.ForceDwarfFrameSection = CodeGenOpts.ForceDwarfFrameSection;
551   Options.EmitCallSiteInfo = CodeGenOpts.EmitCallSiteInfo;
552   Options.ValueTrackingVariableLocations =
553       CodeGenOpts.ValueTrackingVariableLocations;
554   Options.XRayOmitFunctionIndex = CodeGenOpts.XRayOmitFunctionIndex;
555 
556   Options.MCOptions.SplitDwarfFile = CodeGenOpts.SplitDwarfFile;
557   Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
558   Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
559   Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
560   Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
561   Options.MCOptions.MCIncrementalLinkerCompatible =
562       CodeGenOpts.IncrementalLinkerCompatible;
563   Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
564   Options.MCOptions.MCNoWarn = CodeGenOpts.NoWarn;
565   Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
566   Options.MCOptions.PreserveAsmComments = CodeGenOpts.PreserveAsmComments;
567   Options.MCOptions.ABIName = TargetOpts.ABI;
568   for (const auto &Entry : HSOpts.UserEntries)
569     if (!Entry.IsFramework &&
570         (Entry.Group == frontend::IncludeDirGroup::Quoted ||
571          Entry.Group == frontend::IncludeDirGroup::Angled ||
572          Entry.Group == frontend::IncludeDirGroup::System))
573       Options.MCOptions.IASSearchPaths.push_back(
574           Entry.IgnoreSysRoot ? Entry.Path : HSOpts.Sysroot + Entry.Path);
575   Options.MCOptions.Argv0 = CodeGenOpts.Argv0;
576   Options.MCOptions.CommandLineArgs = CodeGenOpts.CommandLineArgs;
577 
578   return true;
579 }
580 
581 static Optional<GCOVOptions> getGCOVOptions(const CodeGenOptions &CodeGenOpts,
582                                             const LangOptions &LangOpts) {
583   if (!CodeGenOpts.EmitGcovArcs && !CodeGenOpts.EmitGcovNotes)
584     return None;
585   // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
586   // LLVM's -default-gcov-version flag is set to something invalid.
587   GCOVOptions Options;
588   Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
589   Options.EmitData = CodeGenOpts.EmitGcovArcs;
590   llvm::copy(CodeGenOpts.CoverageVersion, std::begin(Options.Version));
591   Options.NoRedZone = CodeGenOpts.DisableRedZone;
592   Options.Filter = CodeGenOpts.ProfileFilterFiles;
593   Options.Exclude = CodeGenOpts.ProfileExcludeFiles;
594   Options.Atomic = CodeGenOpts.AtomicProfileUpdate;
595   return Options;
596 }
597 
598 static Optional<InstrProfOptions>
599 getInstrProfOptions(const CodeGenOptions &CodeGenOpts,
600                     const LangOptions &LangOpts) {
601   if (!CodeGenOpts.hasProfileClangInstr())
602     return None;
603   InstrProfOptions Options;
604   Options.NoRedZone = CodeGenOpts.DisableRedZone;
605   Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
606   Options.Atomic = CodeGenOpts.AtomicProfileUpdate;
607   return Options;
608 }
609 
610 void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
611                                       legacy::FunctionPassManager &FPM) {
612   // Handle disabling of all LLVM passes, where we want to preserve the
613   // internal module before any optimization.
614   if (CodeGenOpts.DisableLLVMPasses)
615     return;
616 
617   // Figure out TargetLibraryInfo.  This needs to be added to MPM and FPM
618   // manually (and not via PMBuilder), since some passes (eg. InstrProfiling)
619   // are inserted before PMBuilder ones - they'd get the default-constructed
620   // TLI with an unknown target otherwise.
621   Triple TargetTriple(TheModule->getTargetTriple());
622   std::unique_ptr<TargetLibraryInfoImpl> TLII(
623       createTLII(TargetTriple, CodeGenOpts));
624 
625   // If we reached here with a non-empty index file name, then the index file
626   // was empty and we are not performing ThinLTO backend compilation (used in
627   // testing in a distributed build environment). Drop any the type test
628   // assume sequences inserted for whole program vtables so that codegen doesn't
629   // complain.
630   if (!CodeGenOpts.ThinLTOIndexFile.empty())
631     MPM.add(createLowerTypeTestsPass(/*ExportSummary=*/nullptr,
632                                      /*ImportSummary=*/nullptr,
633                                      /*DropTypeTests=*/true));
634 
635   PassManagerBuilderWrapper PMBuilder(TargetTriple, CodeGenOpts, LangOpts);
636 
637   // At O0 and O1 we only run the always inliner which is more efficient. At
638   // higher optimization levels we run the normal inliner.
639   if (CodeGenOpts.OptimizationLevel <= 1) {
640     bool InsertLifetimeIntrinsics = ((CodeGenOpts.OptimizationLevel != 0 &&
641                                       !CodeGenOpts.DisableLifetimeMarkers) ||
642                                      LangOpts.Coroutines);
643     PMBuilder.Inliner = createAlwaysInlinerLegacyPass(InsertLifetimeIntrinsics);
644   } else {
645     // We do not want to inline hot callsites for SamplePGO module-summary build
646     // because profile annotation will happen again in ThinLTO backend, and we
647     // want the IR of the hot path to match the profile.
648     PMBuilder.Inliner = createFunctionInliningPass(
649         CodeGenOpts.OptimizationLevel, CodeGenOpts.OptimizeSize,
650         (!CodeGenOpts.SampleProfileFile.empty() &&
651          CodeGenOpts.PrepareForThinLTO));
652   }
653 
654   PMBuilder.OptLevel = CodeGenOpts.OptimizationLevel;
655   PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
656   PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
657   PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
658   // Only enable CGProfilePass when using integrated assembler, since
659   // non-integrated assemblers don't recognize .cgprofile section.
660   PMBuilder.CallGraphProfile = !CodeGenOpts.DisableIntegratedAS;
661 
662   PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
663   // Loop interleaving in the loop vectorizer has historically been set to be
664   // enabled when loop unrolling is enabled.
665   PMBuilder.LoopsInterleaved = CodeGenOpts.UnrollLoops;
666   PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
667   PMBuilder.PrepareForThinLTO = CodeGenOpts.PrepareForThinLTO;
668   PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
669   PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
670 
671   MPM.add(new TargetLibraryInfoWrapperPass(*TLII));
672 
673   if (TM)
674     TM->adjustPassManager(PMBuilder);
675 
676   if (CodeGenOpts.DebugInfoForProfiling ||
677       !CodeGenOpts.SampleProfileFile.empty())
678     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
679                            addAddDiscriminatorsPass);
680 
681   // In ObjC ARC mode, add the main ARC optimization passes.
682   if (LangOpts.ObjCAutoRefCount) {
683     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
684                            addObjCARCExpandPass);
685     PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
686                            addObjCARCAPElimPass);
687     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
688                            addObjCARCOptPass);
689   }
690 
691   if (LangOpts.Coroutines)
692     addCoroutinePassesToExtensionPoints(PMBuilder);
693 
694   if (!CodeGenOpts.MemoryProfileOutput.empty()) {
695     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
696                            addMemProfilerPasses);
697     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
698                            addMemProfilerPasses);
699   }
700 
701   if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds)) {
702     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
703                            addBoundsCheckingPass);
704     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
705                            addBoundsCheckingPass);
706   }
707 
708   if (CodeGenOpts.SanitizeCoverageType ||
709       CodeGenOpts.SanitizeCoverageIndirectCalls ||
710       CodeGenOpts.SanitizeCoverageTraceCmp) {
711     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
712                            addSanitizerCoveragePass);
713     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
714                            addSanitizerCoveragePass);
715   }
716 
717   if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
718     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
719                            addAddressSanitizerPasses);
720     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
721                            addAddressSanitizerPasses);
722   }
723 
724   if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
725     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
726                            addKernelAddressSanitizerPasses);
727     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
728                            addKernelAddressSanitizerPasses);
729   }
730 
731   if (LangOpts.Sanitize.has(SanitizerKind::HWAddress)) {
732     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
733                            addHWAddressSanitizerPasses);
734     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
735                            addHWAddressSanitizerPasses);
736   }
737 
738   if (LangOpts.Sanitize.has(SanitizerKind::KernelHWAddress)) {
739     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
740                            addKernelHWAddressSanitizerPasses);
741     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
742                            addKernelHWAddressSanitizerPasses);
743   }
744 
745   if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
746     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
747                            addMemorySanitizerPass);
748     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
749                            addMemorySanitizerPass);
750   }
751 
752   if (LangOpts.Sanitize.has(SanitizerKind::KernelMemory)) {
753     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
754                            addKernelMemorySanitizerPass);
755     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
756                            addKernelMemorySanitizerPass);
757   }
758 
759   if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
760     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
761                            addThreadSanitizerPass);
762     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
763                            addThreadSanitizerPass);
764   }
765 
766   if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
767     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
768                            addDataFlowSanitizerPass);
769     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
770                            addDataFlowSanitizerPass);
771   }
772 
773   // Set up the per-function pass manager.
774   FPM.add(new TargetLibraryInfoWrapperPass(*TLII));
775   if (CodeGenOpts.VerifyModule)
776     FPM.add(createVerifierPass());
777 
778   // Set up the per-module pass manager.
779   if (!CodeGenOpts.RewriteMapFiles.empty())
780     addSymbolRewriterPass(CodeGenOpts, &MPM);
781 
782   // Add UniqueInternalLinkageNames Pass which renames internal linkage symbols
783   // with unique names.
784   if (CodeGenOpts.UniqueInternalLinkageNames) {
785     MPM.add(createUniqueInternalLinkageNamesPass());
786   }
787 
788   if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts, LangOpts)) {
789     MPM.add(createGCOVProfilerPass(*Options));
790     if (CodeGenOpts.getDebugInfo() == codegenoptions::NoDebugInfo)
791       MPM.add(createStripSymbolsPass(true));
792   }
793 
794   if (Optional<InstrProfOptions> Options =
795           getInstrProfOptions(CodeGenOpts, LangOpts))
796     MPM.add(createInstrProfilingLegacyPass(*Options, false));
797 
798   bool hasIRInstr = false;
799   if (CodeGenOpts.hasProfileIRInstr()) {
800     PMBuilder.EnablePGOInstrGen = true;
801     hasIRInstr = true;
802   }
803   if (CodeGenOpts.hasProfileCSIRInstr()) {
804     assert(!CodeGenOpts.hasProfileCSIRUse() &&
805            "Cannot have both CSProfileUse pass and CSProfileGen pass at the "
806            "same time");
807     assert(!hasIRInstr &&
808            "Cannot have both ProfileGen pass and CSProfileGen pass at the "
809            "same time");
810     PMBuilder.EnablePGOCSInstrGen = true;
811     hasIRInstr = true;
812   }
813   if (hasIRInstr) {
814     if (!CodeGenOpts.InstrProfileOutput.empty())
815       PMBuilder.PGOInstrGen = CodeGenOpts.InstrProfileOutput;
816     else
817       PMBuilder.PGOInstrGen = std::string(DefaultProfileGenName);
818   }
819   if (CodeGenOpts.hasProfileIRUse()) {
820     PMBuilder.PGOInstrUse = CodeGenOpts.ProfileInstrumentUsePath;
821     PMBuilder.EnablePGOCSInstrUse = CodeGenOpts.hasProfileCSIRUse();
822   }
823 
824   if (!CodeGenOpts.SampleProfileFile.empty())
825     PMBuilder.PGOSampleUse = CodeGenOpts.SampleProfileFile;
826 
827   PMBuilder.populateFunctionPassManager(FPM);
828   PMBuilder.populateModulePassManager(MPM);
829 }
830 
831 static void setCommandLineOpts(const CodeGenOptions &CodeGenOpts) {
832   SmallVector<const char *, 16> BackendArgs;
833   BackendArgs.push_back("clang"); // Fake program name.
834   if (!CodeGenOpts.DebugPass.empty()) {
835     BackendArgs.push_back("-debug-pass");
836     BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
837   }
838   if (!CodeGenOpts.LimitFloatPrecision.empty()) {
839     BackendArgs.push_back("-limit-float-precision");
840     BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
841   }
842   BackendArgs.push_back(nullptr);
843   llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
844                                     BackendArgs.data());
845 }
846 
847 void EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
848   // Create the TargetMachine for generating code.
849   std::string Error;
850   std::string Triple = TheModule->getTargetTriple();
851   const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
852   if (!TheTarget) {
853     if (MustCreateTM)
854       Diags.Report(diag::err_fe_unable_to_create_target) << Error;
855     return;
856   }
857 
858   Optional<llvm::CodeModel::Model> CM = getCodeModel(CodeGenOpts);
859   std::string FeaturesStr =
860       llvm::join(TargetOpts.Features.begin(), TargetOpts.Features.end(), ",");
861   llvm::Reloc::Model RM = CodeGenOpts.RelocationModel;
862   CodeGenOpt::Level OptLevel = getCGOptLevel(CodeGenOpts);
863 
864   llvm::TargetOptions Options;
865   if (!initTargetOptions(Diags, Options, CodeGenOpts, TargetOpts, LangOpts,
866                          HSOpts))
867     return;
868   TM.reset(TheTarget->createTargetMachine(Triple, TargetOpts.CPU, FeaturesStr,
869                                           Options, RM, CM, OptLevel));
870 }
871 
872 bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
873                                        BackendAction Action,
874                                        raw_pwrite_stream &OS,
875                                        raw_pwrite_stream *DwoOS) {
876   // Add LibraryInfo.
877   llvm::Triple TargetTriple(TheModule->getTargetTriple());
878   std::unique_ptr<TargetLibraryInfoImpl> TLII(
879       createTLII(TargetTriple, CodeGenOpts));
880   CodeGenPasses.add(new TargetLibraryInfoWrapperPass(*TLII));
881 
882   // Normal mode, emit a .s or .o file by running the code generator. Note,
883   // this also adds codegenerator level optimization passes.
884   CodeGenFileType CGFT = getCodeGenFileType(Action);
885 
886   // Add ObjC ARC final-cleanup optimizations. This is done as part of the
887   // "codegen" passes so that it isn't run multiple times when there is
888   // inlining happening.
889   if (CodeGenOpts.OptimizationLevel > 0)
890     CodeGenPasses.add(createObjCARCContractPass());
891 
892   if (TM->addPassesToEmitFile(CodeGenPasses, OS, DwoOS, CGFT,
893                               /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
894     Diags.Report(diag::err_fe_unable_to_interface_with_target);
895     return false;
896   }
897 
898   return true;
899 }
900 
901 void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
902                                       std::unique_ptr<raw_pwrite_stream> OS) {
903   TimeRegion Region(FrontendTimesIsEnabled ? &CodeGenerationTime : nullptr);
904 
905   setCommandLineOpts(CodeGenOpts);
906 
907   bool UsesCodeGen = (Action != Backend_EmitNothing &&
908                       Action != Backend_EmitBC &&
909                       Action != Backend_EmitLL);
910   CreateTargetMachine(UsesCodeGen);
911 
912   if (UsesCodeGen && !TM)
913     return;
914   if (TM)
915     TheModule->setDataLayout(TM->createDataLayout());
916 
917   legacy::PassManager PerModulePasses;
918   PerModulePasses.add(
919       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
920 
921   legacy::FunctionPassManager PerFunctionPasses(TheModule);
922   PerFunctionPasses.add(
923       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
924 
925   CreatePasses(PerModulePasses, PerFunctionPasses);
926 
927   legacy::PassManager CodeGenPasses;
928   CodeGenPasses.add(
929       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
930 
931   std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
932 
933   switch (Action) {
934   case Backend_EmitNothing:
935     break;
936 
937   case Backend_EmitBC:
938     if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
939       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
940         ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
941         if (!ThinLinkOS)
942           return;
943       }
944       TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
945                                CodeGenOpts.EnableSplitLTOUnit);
946       PerModulePasses.add(createWriteThinLTOBitcodePass(
947           *OS, ThinLinkOS ? &ThinLinkOS->os() : nullptr));
948     } else {
949       // Emit a module summary by default for Regular LTO except for ld64
950       // targets
951       bool EmitLTOSummary =
952           (CodeGenOpts.PrepareForLTO &&
953            !CodeGenOpts.DisableLLVMPasses &&
954            llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
955                llvm::Triple::Apple);
956       if (EmitLTOSummary) {
957         if (!TheModule->getModuleFlag("ThinLTO"))
958           TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
959         TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
960                                  uint32_t(1));
961       }
962 
963       PerModulePasses.add(createBitcodeWriterPass(
964           *OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
965     }
966     break;
967 
968   case Backend_EmitLL:
969     PerModulePasses.add(
970         createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
971     break;
972 
973   default:
974     if (!CodeGenOpts.SplitDwarfOutput.empty()) {
975       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
976       if (!DwoOS)
977         return;
978     }
979     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
980                        DwoOS ? &DwoOS->os() : nullptr))
981       return;
982   }
983 
984   // Before executing passes, print the final values of the LLVM options.
985   cl::PrintOptionValues();
986 
987   // Run passes. For now we do all passes at once, but eventually we
988   // would like to have the option of streaming code generation.
989 
990   {
991     PrettyStackTraceString CrashInfo("Per-function optimization");
992     llvm::TimeTraceScope TimeScope("PerFunctionPasses");
993 
994     PerFunctionPasses.doInitialization();
995     for (Function &F : *TheModule)
996       if (!F.isDeclaration())
997         PerFunctionPasses.run(F);
998     PerFunctionPasses.doFinalization();
999   }
1000 
1001   {
1002     PrettyStackTraceString CrashInfo("Per-module optimization passes");
1003     llvm::TimeTraceScope TimeScope("PerModulePasses");
1004     PerModulePasses.run(*TheModule);
1005   }
1006 
1007   {
1008     PrettyStackTraceString CrashInfo("Code generation");
1009     llvm::TimeTraceScope TimeScope("CodeGenPasses");
1010     CodeGenPasses.run(*TheModule);
1011   }
1012 
1013   if (ThinLinkOS)
1014     ThinLinkOS->keep();
1015   if (DwoOS)
1016     DwoOS->keep();
1017 }
1018 
1019 static PassBuilder::OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
1020   switch (Opts.OptimizationLevel) {
1021   default:
1022     llvm_unreachable("Invalid optimization level!");
1023 
1024   case 0:
1025     return PassBuilder::OptimizationLevel::O0;
1026 
1027   case 1:
1028     return PassBuilder::OptimizationLevel::O1;
1029 
1030   case 2:
1031     switch (Opts.OptimizeSize) {
1032     default:
1033       llvm_unreachable("Invalid optimization level for size!");
1034 
1035     case 0:
1036       return PassBuilder::OptimizationLevel::O2;
1037 
1038     case 1:
1039       return PassBuilder::OptimizationLevel::Os;
1040 
1041     case 2:
1042       return PassBuilder::OptimizationLevel::Oz;
1043     }
1044 
1045   case 3:
1046     return PassBuilder::OptimizationLevel::O3;
1047   }
1048 }
1049 
1050 /// A clean version of `EmitAssembly` that uses the new pass manager.
1051 ///
1052 /// Not all features are currently supported in this system, but where
1053 /// necessary it falls back to the legacy pass manager to at least provide
1054 /// basic functionality.
1055 ///
1056 /// This API is planned to have its functionality finished and then to replace
1057 /// `EmitAssembly` at some point in the future when the default switches.
1058 void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
1059     BackendAction Action, std::unique_ptr<raw_pwrite_stream> OS) {
1060   TimeRegion Region(FrontendTimesIsEnabled ? &CodeGenerationTime : nullptr);
1061   setCommandLineOpts(CodeGenOpts);
1062 
1063   bool RequiresCodeGen = (Action != Backend_EmitNothing &&
1064                           Action != Backend_EmitBC &&
1065                           Action != Backend_EmitLL);
1066   CreateTargetMachine(RequiresCodeGen);
1067 
1068   if (RequiresCodeGen && !TM)
1069     return;
1070   if (TM)
1071     TheModule->setDataLayout(TM->createDataLayout());
1072 
1073   Optional<PGOOptions> PGOOpt;
1074 
1075   if (CodeGenOpts.hasProfileIRInstr())
1076     // -fprofile-generate.
1077     PGOOpt = PGOOptions(CodeGenOpts.InstrProfileOutput.empty()
1078                             ? std::string(DefaultProfileGenName)
1079                             : CodeGenOpts.InstrProfileOutput,
1080                         "", "", PGOOptions::IRInstr, PGOOptions::NoCSAction,
1081                         CodeGenOpts.DebugInfoForProfiling);
1082   else if (CodeGenOpts.hasProfileIRUse()) {
1083     // -fprofile-use.
1084     auto CSAction = CodeGenOpts.hasProfileCSIRUse() ? PGOOptions::CSIRUse
1085                                                     : PGOOptions::NoCSAction;
1086     PGOOpt = PGOOptions(CodeGenOpts.ProfileInstrumentUsePath, "",
1087                         CodeGenOpts.ProfileRemappingFile, PGOOptions::IRUse,
1088                         CSAction, CodeGenOpts.DebugInfoForProfiling);
1089   } else if (!CodeGenOpts.SampleProfileFile.empty())
1090     // -fprofile-sample-use
1091     PGOOpt =
1092         PGOOptions(CodeGenOpts.SampleProfileFile, "",
1093                    CodeGenOpts.ProfileRemappingFile, PGOOptions::SampleUse,
1094                    PGOOptions::NoCSAction, CodeGenOpts.DebugInfoForProfiling);
1095   else if (CodeGenOpts.DebugInfoForProfiling)
1096     // -fdebug-info-for-profiling
1097     PGOOpt = PGOOptions("", "", "", PGOOptions::NoAction,
1098                         PGOOptions::NoCSAction, true);
1099 
1100   // Check to see if we want to generate a CS profile.
1101   if (CodeGenOpts.hasProfileCSIRInstr()) {
1102     assert(!CodeGenOpts.hasProfileCSIRUse() &&
1103            "Cannot have both CSProfileUse pass and CSProfileGen pass at "
1104            "the same time");
1105     if (PGOOpt.hasValue()) {
1106       assert(PGOOpt->Action != PGOOptions::IRInstr &&
1107              PGOOpt->Action != PGOOptions::SampleUse &&
1108              "Cannot run CSProfileGen pass with ProfileGen or SampleUse "
1109              " pass");
1110       PGOOpt->CSProfileGenFile = CodeGenOpts.InstrProfileOutput.empty()
1111                                      ? std::string(DefaultProfileGenName)
1112                                      : CodeGenOpts.InstrProfileOutput;
1113       PGOOpt->CSAction = PGOOptions::CSIRInstr;
1114     } else
1115       PGOOpt = PGOOptions("",
1116                           CodeGenOpts.InstrProfileOutput.empty()
1117                               ? std::string(DefaultProfileGenName)
1118                               : CodeGenOpts.InstrProfileOutput,
1119                           "", PGOOptions::NoAction, PGOOptions::CSIRInstr,
1120                           CodeGenOpts.DebugInfoForProfiling);
1121   }
1122 
1123   PipelineTuningOptions PTO;
1124   PTO.LoopUnrolling = CodeGenOpts.UnrollLoops;
1125   // For historical reasons, loop interleaving is set to mirror setting for loop
1126   // unrolling.
1127   PTO.LoopInterleaving = CodeGenOpts.UnrollLoops;
1128   PTO.LoopVectorization = CodeGenOpts.VectorizeLoop;
1129   PTO.SLPVectorization = CodeGenOpts.VectorizeSLP;
1130   // Only enable CGProfilePass when using integrated assembler, since
1131   // non-integrated assemblers don't recognize .cgprofile section.
1132   PTO.CallGraphProfile = !CodeGenOpts.DisableIntegratedAS;
1133   PTO.Coroutines = LangOpts.Coroutines;
1134 
1135   PassInstrumentationCallbacks PIC;
1136   StandardInstrumentations SI(CodeGenOpts.DebugPassManager);
1137   SI.registerCallbacks(PIC);
1138   PassBuilder PB(CodeGenOpts.DebugPassManager, TM.get(), PTO, PGOOpt, &PIC);
1139 
1140   // Attempt to load pass plugins and register their callbacks with PB.
1141   for (auto &PluginFN : CodeGenOpts.PassPlugins) {
1142     auto PassPlugin = PassPlugin::Load(PluginFN);
1143     if (PassPlugin) {
1144       PassPlugin->registerPassBuilderCallbacks(PB);
1145     } else {
1146       Diags.Report(diag::err_fe_unable_to_load_plugin)
1147           << PluginFN << toString(PassPlugin.takeError());
1148     }
1149   }
1150 #define HANDLE_EXTENSION(Ext)                                                  \
1151   get##Ext##PluginInfo().RegisterPassBuilderCallbacks(PB);
1152 #include "llvm/Support/Extension.def"
1153 
1154   LoopAnalysisManager LAM(CodeGenOpts.DebugPassManager);
1155   FunctionAnalysisManager FAM(CodeGenOpts.DebugPassManager);
1156   CGSCCAnalysisManager CGAM(CodeGenOpts.DebugPassManager);
1157   ModuleAnalysisManager MAM(CodeGenOpts.DebugPassManager);
1158 
1159   // Register the AA manager first so that our version is the one used.
1160   FAM.registerPass([&] { return PB.buildDefaultAAPipeline(); });
1161 
1162   // Register the target library analysis directly and give it a customized
1163   // preset TLI.
1164   Triple TargetTriple(TheModule->getTargetTriple());
1165   std::unique_ptr<TargetLibraryInfoImpl> TLII(
1166       createTLII(TargetTriple, CodeGenOpts));
1167   FAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); });
1168 
1169   // Register all the basic analyses with the managers.
1170   PB.registerModuleAnalyses(MAM);
1171   PB.registerCGSCCAnalyses(CGAM);
1172   PB.registerFunctionAnalyses(FAM);
1173   PB.registerLoopAnalyses(LAM);
1174   PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
1175 
1176   ModulePassManager MPM(CodeGenOpts.DebugPassManager);
1177 
1178   if (!CodeGenOpts.DisableLLVMPasses) {
1179     // Map our optimization levels into one of the distinct levels used to
1180     // configure the pipeline.
1181     PassBuilder::OptimizationLevel Level = mapToLevel(CodeGenOpts);
1182 
1183     bool IsThinLTO = CodeGenOpts.PrepareForThinLTO;
1184     bool IsLTO = CodeGenOpts.PrepareForLTO;
1185 
1186     // If we reached here with a non-empty index file name, then the index
1187     // file was empty and we are not performing ThinLTO backend compilation
1188     // (used in testing in a distributed build environment). Drop any the type
1189     // test assume sequences inserted for whole program vtables so that
1190     // codegen doesn't complain.
1191     if (!CodeGenOpts.ThinLTOIndexFile.empty())
1192       PB.registerPipelineStartEPCallback(
1193           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1194             MPM.addPass(LowerTypeTestsPass(/*ExportSummary=*/nullptr,
1195                                            /*ImportSummary=*/nullptr,
1196                                            /*DropTypeTests=*/true));
1197           });
1198 
1199     if (Level != PassBuilder::OptimizationLevel::O0) {
1200       PB.registerPipelineStartEPCallback(
1201           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1202             MPM.addPass(createModuleToFunctionPassAdaptor(
1203                 EntryExitInstrumenterPass(/*PostInlining=*/false)));
1204           });
1205     }
1206 
1207     // Register callbacks to schedule sanitizer passes at the appropriate part
1208     // of the pipeline.
1209     if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
1210       PB.registerScalarOptimizerLateEPCallback(
1211           [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
1212             FPM.addPass(BoundsCheckingPass());
1213           });
1214 
1215     if (CodeGenOpts.SanitizeCoverageType ||
1216         CodeGenOpts.SanitizeCoverageIndirectCalls ||
1217         CodeGenOpts.SanitizeCoverageTraceCmp) {
1218       PB.registerOptimizerLastEPCallback(
1219           [this](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1220             auto SancovOpts = getSancovOptsFromCGOpts(CodeGenOpts);
1221             MPM.addPass(ModuleSanitizerCoveragePass(
1222                 SancovOpts, CodeGenOpts.SanitizeCoverageAllowlistFiles,
1223                 CodeGenOpts.SanitizeCoverageBlocklistFiles));
1224           });
1225     }
1226 
1227     if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
1228       int TrackOrigins = CodeGenOpts.SanitizeMemoryTrackOrigins;
1229       bool Recover = CodeGenOpts.SanitizeRecover.has(SanitizerKind::Memory);
1230       PB.registerOptimizerLastEPCallback(
1231           [TrackOrigins, Recover](ModulePassManager &MPM,
1232                                   PassBuilder::OptimizationLevel Level) {
1233             MPM.addPass(MemorySanitizerPass({TrackOrigins, Recover, false}));
1234             MPM.addPass(createModuleToFunctionPassAdaptor(
1235                 MemorySanitizerPass({TrackOrigins, Recover, false})));
1236           });
1237     }
1238     if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
1239       PB.registerOptimizerLastEPCallback(
1240           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1241             MPM.addPass(ThreadSanitizerPass());
1242             MPM.addPass(
1243                 createModuleToFunctionPassAdaptor(ThreadSanitizerPass()));
1244           });
1245     }
1246 
1247     auto ASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
1248       if (LangOpts.Sanitize.has(Mask)) {
1249         bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
1250         bool UseAfterScope = CodeGenOpts.SanitizeAddressUseAfterScope;
1251         bool ModuleUseAfterScope = asanUseGlobalsGC(TargetTriple, CodeGenOpts);
1252         bool UseOdrIndicator = CodeGenOpts.SanitizeAddressUseOdrIndicator;
1253         PB.registerOptimizerLastEPCallback(
1254             [CompileKernel, Recover, UseAfterScope, ModuleUseAfterScope,
1255              UseOdrIndicator](ModulePassManager &MPM,
1256                               PassBuilder::OptimizationLevel Level) {
1257               MPM.addPass(
1258                   RequireAnalysisPass<ASanGlobalsMetadataAnalysis, Module>());
1259               MPM.addPass(ModuleAddressSanitizerPass(CompileKernel, Recover,
1260                                                      ModuleUseAfterScope,
1261                                                      UseOdrIndicator));
1262               MPM.addPass(createModuleToFunctionPassAdaptor(
1263                   AddressSanitizerPass(CompileKernel, Recover, UseAfterScope)));
1264             });
1265       }
1266     };
1267     ASanPass(SanitizerKind::Address, false);
1268     ASanPass(SanitizerKind::KernelAddress, true);
1269 
1270     auto HWASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
1271       if (LangOpts.Sanitize.has(Mask)) {
1272         bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
1273         PB.registerOptimizerLastEPCallback(
1274             [CompileKernel, Recover](ModulePassManager &MPM,
1275                                      PassBuilder::OptimizationLevel Level) {
1276               MPM.addPass(HWAddressSanitizerPass(CompileKernel, Recover));
1277             });
1278       }
1279     };
1280     HWASanPass(SanitizerKind::HWAddress, false);
1281     HWASanPass(SanitizerKind::KernelHWAddress, true);
1282 
1283     if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
1284       PB.registerOptimizerLastEPCallback(
1285           [this](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1286             MPM.addPass(
1287                 DataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
1288           });
1289     }
1290 
1291     if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts, LangOpts))
1292       PB.registerPipelineStartEPCallback(
1293           [Options](ModulePassManager &MPM,
1294                     PassBuilder::OptimizationLevel Level) {
1295             MPM.addPass(GCOVProfilerPass(*Options));
1296           });
1297     if (Optional<InstrProfOptions> Options =
1298             getInstrProfOptions(CodeGenOpts, LangOpts))
1299       PB.registerPipelineStartEPCallback(
1300           [Options](ModulePassManager &MPM,
1301                     PassBuilder::OptimizationLevel Level) {
1302             MPM.addPass(InstrProfiling(*Options, false));
1303           });
1304 
1305     if (CodeGenOpts.OptimizationLevel == 0) {
1306       MPM = PB.buildO0DefaultPipeline(Level, IsLTO || IsThinLTO);
1307     } else if (IsThinLTO) {
1308       MPM = PB.buildThinLTOPreLinkDefaultPipeline(Level);
1309     } else if (IsLTO) {
1310       MPM = PB.buildLTOPreLinkDefaultPipeline(Level);
1311     } else {
1312       MPM = PB.buildPerModuleDefaultPipeline(Level);
1313     }
1314 
1315     // Add UniqueInternalLinkageNames Pass which renames internal linkage
1316     // symbols with unique names.
1317     if (CodeGenOpts.UniqueInternalLinkageNames)
1318       MPM.addPass(UniqueInternalLinkageNamesPass());
1319 
1320     if (!CodeGenOpts.MemoryProfileOutput.empty()) {
1321       MPM.addPass(createModuleToFunctionPassAdaptor(MemProfilerPass()));
1322       MPM.addPass(ModuleMemProfilerPass());
1323     }
1324   }
1325 
1326   // FIXME: We still use the legacy pass manager to do code generation. We
1327   // create that pass manager here and use it as needed below.
1328   legacy::PassManager CodeGenPasses;
1329   bool NeedCodeGen = false;
1330   std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
1331 
1332   // Append any output we need to the pass manager.
1333   switch (Action) {
1334   case Backend_EmitNothing:
1335     break;
1336 
1337   case Backend_EmitBC:
1338     if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
1339       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
1340         ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
1341         if (!ThinLinkOS)
1342           return;
1343       }
1344       TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1345                                CodeGenOpts.EnableSplitLTOUnit);
1346       MPM.addPass(ThinLTOBitcodeWriterPass(*OS, ThinLinkOS ? &ThinLinkOS->os()
1347                                                            : nullptr));
1348     } else {
1349       // Emit a module summary by default for Regular LTO except for ld64
1350       // targets
1351       bool EmitLTOSummary =
1352           (CodeGenOpts.PrepareForLTO &&
1353            !CodeGenOpts.DisableLLVMPasses &&
1354            llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
1355                llvm::Triple::Apple);
1356       if (EmitLTOSummary) {
1357         if (!TheModule->getModuleFlag("ThinLTO"))
1358           TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
1359         TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1360                                  uint32_t(1));
1361       }
1362       MPM.addPass(
1363           BitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
1364     }
1365     break;
1366 
1367   case Backend_EmitLL:
1368     MPM.addPass(PrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
1369     break;
1370 
1371   case Backend_EmitAssembly:
1372   case Backend_EmitMCNull:
1373   case Backend_EmitObj:
1374     NeedCodeGen = true;
1375     CodeGenPasses.add(
1376         createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
1377     if (!CodeGenOpts.SplitDwarfOutput.empty()) {
1378       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
1379       if (!DwoOS)
1380         return;
1381     }
1382     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
1383                        DwoOS ? &DwoOS->os() : nullptr))
1384       // FIXME: Should we handle this error differently?
1385       return;
1386     break;
1387   }
1388 
1389   // Before executing passes, print the final values of the LLVM options.
1390   cl::PrintOptionValues();
1391 
1392   // Now that we have all of the passes ready, run them.
1393   {
1394     PrettyStackTraceString CrashInfo("Optimizer");
1395     MPM.run(*TheModule, MAM);
1396   }
1397 
1398   // Now if needed, run the legacy PM for codegen.
1399   if (NeedCodeGen) {
1400     PrettyStackTraceString CrashInfo("Code generation");
1401     CodeGenPasses.run(*TheModule);
1402   }
1403 
1404   if (ThinLinkOS)
1405     ThinLinkOS->keep();
1406   if (DwoOS)
1407     DwoOS->keep();
1408 }
1409 
1410 static void runThinLTOBackend(
1411     DiagnosticsEngine &Diags, ModuleSummaryIndex *CombinedIndex, Module *M,
1412     const HeaderSearchOptions &HeaderOpts, const CodeGenOptions &CGOpts,
1413     const clang::TargetOptions &TOpts, const LangOptions &LOpts,
1414     std::unique_ptr<raw_pwrite_stream> OS, std::string SampleProfile,
1415     std::string ProfileRemapping, BackendAction Action) {
1416   StringMap<DenseMap<GlobalValue::GUID, GlobalValueSummary *>>
1417       ModuleToDefinedGVSummaries;
1418   CombinedIndex->collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries);
1419 
1420   setCommandLineOpts(CGOpts);
1421 
1422   // We can simply import the values mentioned in the combined index, since
1423   // we should only invoke this using the individual indexes written out
1424   // via a WriteIndexesThinBackend.
1425   FunctionImporter::ImportMapTy ImportList;
1426   std::vector<std::unique_ptr<llvm::MemoryBuffer>> OwnedImports;
1427   MapVector<llvm::StringRef, llvm::BitcodeModule> ModuleMap;
1428   if (!lto::loadReferencedModules(*M, *CombinedIndex, ImportList, ModuleMap,
1429                                   OwnedImports))
1430     return;
1431 
1432   auto AddStream = [&](size_t Task) {
1433     return std::make_unique<lto::NativeObjectStream>(std::move(OS));
1434   };
1435   lto::Config Conf;
1436   if (CGOpts.SaveTempsFilePrefix != "") {
1437     if (Error E = Conf.addSaveTemps(CGOpts.SaveTempsFilePrefix + ".",
1438                                     /* UseInputModulePath */ false)) {
1439       handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1440         errs() << "Error setting up ThinLTO save-temps: " << EIB.message()
1441                << '\n';
1442       });
1443     }
1444   }
1445   Conf.CPU = TOpts.CPU;
1446   Conf.CodeModel = getCodeModel(CGOpts);
1447   Conf.MAttrs = TOpts.Features;
1448   Conf.RelocModel = CGOpts.RelocationModel;
1449   Conf.CGOptLevel = getCGOptLevel(CGOpts);
1450   Conf.OptLevel = CGOpts.OptimizationLevel;
1451   initTargetOptions(Diags, Conf.Options, CGOpts, TOpts, LOpts, HeaderOpts);
1452   Conf.SampleProfile = std::move(SampleProfile);
1453   Conf.PTO.LoopUnrolling = CGOpts.UnrollLoops;
1454   // For historical reasons, loop interleaving is set to mirror setting for loop
1455   // unrolling.
1456   Conf.PTO.LoopInterleaving = CGOpts.UnrollLoops;
1457   Conf.PTO.LoopVectorization = CGOpts.VectorizeLoop;
1458   Conf.PTO.SLPVectorization = CGOpts.VectorizeSLP;
1459   // Only enable CGProfilePass when using integrated assembler, since
1460   // non-integrated assemblers don't recognize .cgprofile section.
1461   Conf.PTO.CallGraphProfile = !CGOpts.DisableIntegratedAS;
1462 
1463   // Context sensitive profile.
1464   if (CGOpts.hasProfileCSIRInstr()) {
1465     Conf.RunCSIRInstr = true;
1466     Conf.CSIRProfile = std::move(CGOpts.InstrProfileOutput);
1467   } else if (CGOpts.hasProfileCSIRUse()) {
1468     Conf.RunCSIRInstr = false;
1469     Conf.CSIRProfile = std::move(CGOpts.ProfileInstrumentUsePath);
1470   }
1471 
1472   Conf.ProfileRemapping = std::move(ProfileRemapping);
1473   Conf.UseNewPM = CGOpts.ExperimentalNewPassManager;
1474   Conf.DebugPassManager = CGOpts.DebugPassManager;
1475   Conf.RemarksWithHotness = CGOpts.DiagnosticsWithHotness;
1476   Conf.RemarksFilename = CGOpts.OptRecordFile;
1477   Conf.RemarksPasses = CGOpts.OptRecordPasses;
1478   Conf.RemarksFormat = CGOpts.OptRecordFormat;
1479   Conf.SplitDwarfFile = CGOpts.SplitDwarfFile;
1480   Conf.SplitDwarfOutput = CGOpts.SplitDwarfOutput;
1481   switch (Action) {
1482   case Backend_EmitNothing:
1483     Conf.PreCodeGenModuleHook = [](size_t Task, const Module &Mod) {
1484       return false;
1485     };
1486     break;
1487   case Backend_EmitLL:
1488     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1489       M->print(*OS, nullptr, CGOpts.EmitLLVMUseLists);
1490       return false;
1491     };
1492     break;
1493   case Backend_EmitBC:
1494     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1495       WriteBitcodeToFile(*M, *OS, CGOpts.EmitLLVMUseLists);
1496       return false;
1497     };
1498     break;
1499   default:
1500     Conf.CGFileType = getCodeGenFileType(Action);
1501     break;
1502   }
1503   if (Error E =
1504           thinBackend(Conf, -1, AddStream, *M, *CombinedIndex, ImportList,
1505                       ModuleToDefinedGVSummaries[M->getModuleIdentifier()],
1506                       ModuleMap, CGOpts.CmdArgs)) {
1507     handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1508       errs() << "Error running ThinLTO backend: " << EIB.message() << '\n';
1509     });
1510   }
1511 }
1512 
1513 void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
1514                               const HeaderSearchOptions &HeaderOpts,
1515                               const CodeGenOptions &CGOpts,
1516                               const clang::TargetOptions &TOpts,
1517                               const LangOptions &LOpts,
1518                               const llvm::DataLayout &TDesc, Module *M,
1519                               BackendAction Action,
1520                               std::unique_ptr<raw_pwrite_stream> OS) {
1521 
1522   llvm::TimeTraceScope TimeScope("Backend");
1523 
1524   std::unique_ptr<llvm::Module> EmptyModule;
1525   if (!CGOpts.ThinLTOIndexFile.empty()) {
1526     // If we are performing a ThinLTO importing compile, load the function index
1527     // into memory and pass it into runThinLTOBackend, which will run the
1528     // function importer and invoke LTO passes.
1529     Expected<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
1530         llvm::getModuleSummaryIndexForFile(CGOpts.ThinLTOIndexFile,
1531                                            /*IgnoreEmptyThinLTOIndexFile*/true);
1532     if (!IndexOrErr) {
1533       logAllUnhandledErrors(IndexOrErr.takeError(), errs(),
1534                             "Error loading index file '" +
1535                             CGOpts.ThinLTOIndexFile + "': ");
1536       return;
1537     }
1538     std::unique_ptr<ModuleSummaryIndex> CombinedIndex = std::move(*IndexOrErr);
1539     // A null CombinedIndex means we should skip ThinLTO compilation
1540     // (LLVM will optionally ignore empty index files, returning null instead
1541     // of an error).
1542     if (CombinedIndex) {
1543       if (!CombinedIndex->skipModuleByDistributedBackend()) {
1544         runThinLTOBackend(Diags, CombinedIndex.get(), M, HeaderOpts, CGOpts,
1545                           TOpts, LOpts, std::move(OS), CGOpts.SampleProfileFile,
1546                           CGOpts.ProfileRemappingFile, Action);
1547         return;
1548       }
1549       // Distributed indexing detected that nothing from the module is needed
1550       // for the final linking. So we can skip the compilation. We sill need to
1551       // output an empty object file to make sure that a linker does not fail
1552       // trying to read it. Also for some features, like CFI, we must skip
1553       // the compilation as CombinedIndex does not contain all required
1554       // information.
1555       EmptyModule = std::make_unique<llvm::Module>("empty", M->getContext());
1556       EmptyModule->setTargetTriple(M->getTargetTriple());
1557       M = EmptyModule.get();
1558     }
1559   }
1560 
1561   EmitAssemblyHelper AsmHelper(Diags, HeaderOpts, CGOpts, TOpts, LOpts, M);
1562 
1563   if (CGOpts.ExperimentalNewPassManager)
1564     AsmHelper.EmitAssemblyWithNewPassManager(Action, std::move(OS));
1565   else
1566     AsmHelper.EmitAssembly(Action, std::move(OS));
1567 
1568   // Verify clang's TargetInfo DataLayout against the LLVM TargetMachine's
1569   // DataLayout.
1570   if (AsmHelper.TM) {
1571     std::string DLDesc = M->getDataLayout().getStringRepresentation();
1572     if (DLDesc != TDesc.getStringRepresentation()) {
1573       unsigned DiagID = Diags.getCustomDiagID(
1574           DiagnosticsEngine::Error, "backend data layout '%0' does not match "
1575                                     "expected target description '%1'");
1576       Diags.Report(DiagID) << DLDesc << TDesc.getStringRepresentation();
1577     }
1578   }
1579 }
1580 
1581 // With -fembed-bitcode, save a copy of the llvm IR as data in the
1582 // __LLVM,__bitcode section.
1583 void clang::EmbedBitcode(llvm::Module *M, const CodeGenOptions &CGOpts,
1584                          llvm::MemoryBufferRef Buf) {
1585   if (CGOpts.getEmbedBitcode() == CodeGenOptions::Embed_Off)
1586     return;
1587   llvm::EmbedBitcodeInModule(
1588       *M, Buf, CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Marker,
1589       CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Bitcode,
1590       CGOpts.CmdArgs);
1591 }
1592