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/AliasAnalysis.h"
22 #include "llvm/Analysis/StackSafetyAnalysis.h"
23 #include "llvm/Analysis/TargetLibraryInfo.h"
24 #include "llvm/Analysis/TargetTransformInfo.h"
25 #include "llvm/Bitcode/BitcodeReader.h"
26 #include "llvm/Bitcode/BitcodeWriter.h"
27 #include "llvm/Bitcode/BitcodeWriterPass.h"
28 #include "llvm/CodeGen/RegAllocRegistry.h"
29 #include "llvm/CodeGen/SchedulerRegistry.h"
30 #include "llvm/CodeGen/TargetSubtargetInfo.h"
31 #include "llvm/IR/DataLayout.h"
32 #include "llvm/IR/IRPrintingPasses.h"
33 #include "llvm/IR/LegacyPassManager.h"
34 #include "llvm/IR/Module.h"
35 #include "llvm/IR/ModuleSummaryIndex.h"
36 #include "llvm/IR/PassManager.h"
37 #include "llvm/IR/Verifier.h"
38 #include "llvm/LTO/LTOBackend.h"
39 #include "llvm/MC/MCAsmInfo.h"
40 #include "llvm/MC/SubtargetFeature.h"
41 #include "llvm/Passes/PassBuilder.h"
42 #include "llvm/Passes/PassPlugin.h"
43 #include "llvm/Passes/StandardInstrumentations.h"
44 #include "llvm/Support/BuryPointer.h"
45 #include "llvm/Support/CommandLine.h"
46 #include "llvm/Support/MemoryBuffer.h"
47 #include "llvm/Support/PrettyStackTrace.h"
48 #include "llvm/Support/TargetRegistry.h"
49 #include "llvm/Support/TimeProfiler.h"
50 #include "llvm/Support/Timer.h"
51 #include "llvm/Support/ToolOutputFile.h"
52 #include "llvm/Support/raw_ostream.h"
53 #include "llvm/Target/TargetMachine.h"
54 #include "llvm/Target/TargetOptions.h"
55 #include "llvm/Transforms/Coroutines.h"
56 #include "llvm/Transforms/Coroutines/CoroCleanup.h"
57 #include "llvm/Transforms/Coroutines/CoroEarly.h"
58 #include "llvm/Transforms/Coroutines/CoroElide.h"
59 #include "llvm/Transforms/Coroutines/CoroSplit.h"
60 #include "llvm/Transforms/IPO.h"
61 #include "llvm/Transforms/IPO/AlwaysInliner.h"
62 #include "llvm/Transforms/IPO/LowerTypeTests.h"
63 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
64 #include "llvm/Transforms/IPO/ThinLTOBitcodeWriter.h"
65 #include "llvm/Transforms/InstCombine/InstCombine.h"
66 #include "llvm/Transforms/Instrumentation.h"
67 #include "llvm/Transforms/Instrumentation/AddressSanitizer.h"
68 #include "llvm/Transforms/Instrumentation/BoundsChecking.h"
69 #include "llvm/Transforms/Instrumentation/DataFlowSanitizer.h"
70 #include "llvm/Transforms/Instrumentation/GCOVProfiler.h"
71 #include "llvm/Transforms/Instrumentation/HWAddressSanitizer.h"
72 #include "llvm/Transforms/Instrumentation/InstrProfiling.h"
73 #include "llvm/Transforms/Instrumentation/MemProfiler.h"
74 #include "llvm/Transforms/Instrumentation/MemorySanitizer.h"
75 #include "llvm/Transforms/Instrumentation/SanitizerCoverage.h"
76 #include "llvm/Transforms/Instrumentation/ThreadSanitizer.h"
77 #include "llvm/Transforms/ObjCARC.h"
78 #include "llvm/Transforms/Scalar.h"
79 #include "llvm/Transforms/Scalar/EarlyCSE.h"
80 #include "llvm/Transforms/Scalar/GVN.h"
81 #include "llvm/Transforms/Scalar/LowerMatrixIntrinsics.h"
82 #include "llvm/Transforms/Utils.h"
83 #include "llvm/Transforms/Utils/CanonicalizeAliases.h"
84 #include "llvm/Transforms/Utils/EntryExitInstrumenter.h"
85 #include "llvm/Transforms/Utils/NameAnonGlobals.h"
86 #include "llvm/Transforms/Utils/SymbolRewriter.h"
87 #include <memory>
88 using namespace clang;
89 using namespace llvm;
90 
91 #define HANDLE_EXTENSION(Ext)                                                  \
92   llvm::PassPluginLibraryInfo get##Ext##PluginInfo();
93 #include "llvm/Support/Extension.def"
94 
95 namespace {
96 
97 // Default filename used for profile generation.
98 static constexpr StringLiteral DefaultProfileGenName = "default_%m.profraw";
99 
100 class EmitAssemblyHelper {
101   DiagnosticsEngine &Diags;
102   const HeaderSearchOptions &HSOpts;
103   const CodeGenOptions &CodeGenOpts;
104   const clang::TargetOptions &TargetOpts;
105   const LangOptions &LangOpts;
106   Module *TheModule;
107 
108   Timer CodeGenerationTime;
109 
110   std::unique_ptr<raw_pwrite_stream> OS;
111 
112   TargetIRAnalysis getTargetIRAnalysis() const {
113     if (TM)
114       return TM->getTargetIRAnalysis();
115 
116     return TargetIRAnalysis();
117   }
118 
119   void CreatePasses(legacy::PassManager &MPM, legacy::FunctionPassManager &FPM);
120 
121   /// Generates the TargetMachine.
122   /// Leaves TM unchanged if it is unable to create the target machine.
123   /// Some of our clang tests specify triples which are not built
124   /// into clang. This is okay because these tests check the generated
125   /// IR, and they require DataLayout which depends on the triple.
126   /// In this case, we allow this method to fail and not report an error.
127   /// When MustCreateTM is used, we print an error if we are unable to load
128   /// the requested target.
129   void CreateTargetMachine(bool MustCreateTM);
130 
131   /// Add passes necessary to emit assembly or LLVM IR.
132   ///
133   /// \return True on success.
134   bool AddEmitPasses(legacy::PassManager &CodeGenPasses, BackendAction Action,
135                      raw_pwrite_stream &OS, raw_pwrite_stream *DwoOS);
136 
137   std::unique_ptr<llvm::ToolOutputFile> openOutputFile(StringRef Path) {
138     std::error_code EC;
139     auto F = std::make_unique<llvm::ToolOutputFile>(Path, EC,
140                                                      llvm::sys::fs::OF_None);
141     if (EC) {
142       Diags.Report(diag::err_fe_unable_to_open_output) << Path << EC.message();
143       F.reset();
144     }
145     return F;
146   }
147 
148 public:
149   EmitAssemblyHelper(DiagnosticsEngine &_Diags,
150                      const HeaderSearchOptions &HeaderSearchOpts,
151                      const CodeGenOptions &CGOpts,
152                      const clang::TargetOptions &TOpts,
153                      const LangOptions &LOpts, Module *M)
154       : Diags(_Diags), HSOpts(HeaderSearchOpts), CodeGenOpts(CGOpts),
155         TargetOpts(TOpts), LangOpts(LOpts), TheModule(M),
156         CodeGenerationTime("codegen", "Code Generation Time") {}
157 
158   ~EmitAssemblyHelper() {
159     if (CodeGenOpts.DisableFree)
160       BuryPointer(std::move(TM));
161   }
162 
163   std::unique_ptr<TargetMachine> TM;
164 
165   void EmitAssembly(BackendAction Action,
166                     std::unique_ptr<raw_pwrite_stream> OS);
167 
168   void EmitAssemblyWithNewPassManager(BackendAction Action,
169                                       std::unique_ptr<raw_pwrite_stream> OS);
170 };
171 
172 // We need this wrapper to access LangOpts and CGOpts from extension functions
173 // that we add to the PassManagerBuilder.
174 class PassManagerBuilderWrapper : public PassManagerBuilder {
175 public:
176   PassManagerBuilderWrapper(const Triple &TargetTriple,
177                             const CodeGenOptions &CGOpts,
178                             const LangOptions &LangOpts)
179       : PassManagerBuilder(), TargetTriple(TargetTriple), CGOpts(CGOpts),
180         LangOpts(LangOpts) {}
181   const Triple &getTargetTriple() const { return TargetTriple; }
182   const CodeGenOptions &getCGOpts() const { return CGOpts; }
183   const LangOptions &getLangOpts() const { return LangOpts; }
184 
185 private:
186   const Triple &TargetTriple;
187   const CodeGenOptions &CGOpts;
188   const LangOptions &LangOpts;
189 };
190 }
191 
192 static void addObjCARCAPElimPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
193   if (Builder.OptLevel > 0)
194     PM.add(createObjCARCAPElimPass());
195 }
196 
197 static void addObjCARCExpandPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
198   if (Builder.OptLevel > 0)
199     PM.add(createObjCARCExpandPass());
200 }
201 
202 static void addObjCARCOptPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
203   if (Builder.OptLevel > 0)
204     PM.add(createObjCARCOptPass());
205 }
206 
207 static void addAddDiscriminatorsPass(const PassManagerBuilder &Builder,
208                                      legacy::PassManagerBase &PM) {
209   PM.add(createAddDiscriminatorsPass());
210 }
211 
212 static void addBoundsCheckingPass(const PassManagerBuilder &Builder,
213                                   legacy::PassManagerBase &PM) {
214   PM.add(createBoundsCheckingLegacyPass());
215 }
216 
217 static SanitizerCoverageOptions
218 getSancovOptsFromCGOpts(const CodeGenOptions &CGOpts) {
219   SanitizerCoverageOptions Opts;
220   Opts.CoverageType =
221       static_cast<SanitizerCoverageOptions::Type>(CGOpts.SanitizeCoverageType);
222   Opts.IndirectCalls = CGOpts.SanitizeCoverageIndirectCalls;
223   Opts.TraceBB = CGOpts.SanitizeCoverageTraceBB;
224   Opts.TraceCmp = CGOpts.SanitizeCoverageTraceCmp;
225   Opts.TraceDiv = CGOpts.SanitizeCoverageTraceDiv;
226   Opts.TraceGep = CGOpts.SanitizeCoverageTraceGep;
227   Opts.Use8bitCounters = CGOpts.SanitizeCoverage8bitCounters;
228   Opts.TracePC = CGOpts.SanitizeCoverageTracePC;
229   Opts.TracePCGuard = CGOpts.SanitizeCoverageTracePCGuard;
230   Opts.NoPrune = CGOpts.SanitizeCoverageNoPrune;
231   Opts.Inline8bitCounters = CGOpts.SanitizeCoverageInline8bitCounters;
232   Opts.InlineBoolFlag = CGOpts.SanitizeCoverageInlineBoolFlag;
233   Opts.PCTable = CGOpts.SanitizeCoveragePCTable;
234   Opts.StackDepth = CGOpts.SanitizeCoverageStackDepth;
235   return Opts;
236 }
237 
238 static void addSanitizerCoveragePass(const PassManagerBuilder &Builder,
239                                      legacy::PassManagerBase &PM) {
240   const PassManagerBuilderWrapper &BuilderWrapper =
241       static_cast<const PassManagerBuilderWrapper &>(Builder);
242   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
243   auto Opts = getSancovOptsFromCGOpts(CGOpts);
244   PM.add(createModuleSanitizerCoverageLegacyPassPass(
245       Opts, CGOpts.SanitizeCoverageAllowlistFiles,
246       CGOpts.SanitizeCoverageBlocklistFiles));
247 }
248 
249 // Check if ASan should use GC-friendly instrumentation for globals.
250 // First of all, there is no point if -fdata-sections is off (expect for MachO,
251 // where this is not a factor). Also, on ELF this feature requires an assembler
252 // extension that only works with -integrated-as at the moment.
253 static bool asanUseGlobalsGC(const Triple &T, const CodeGenOptions &CGOpts) {
254   if (!CGOpts.SanitizeAddressGlobalsDeadStripping)
255     return false;
256   switch (T.getObjectFormat()) {
257   case Triple::MachO:
258   case Triple::COFF:
259     return true;
260   case Triple::ELF:
261     return CGOpts.DataSections && !CGOpts.DisableIntegratedAS;
262   case Triple::GOFF:
263     llvm::report_fatal_error("ASan not implemented for GOFF");
264   case Triple::XCOFF:
265     llvm::report_fatal_error("ASan not implemented for XCOFF.");
266   case Triple::Wasm:
267   case Triple::UnknownObjectFormat:
268     break;
269   }
270   return false;
271 }
272 
273 static void addMemProfilerPasses(const PassManagerBuilder &Builder,
274                                  legacy::PassManagerBase &PM) {
275   PM.add(createMemProfilerFunctionPass());
276   PM.add(createModuleMemProfilerLegacyPassPass());
277 }
278 
279 static void addAddressSanitizerPasses(const PassManagerBuilder &Builder,
280                                       legacy::PassManagerBase &PM) {
281   const PassManagerBuilderWrapper &BuilderWrapper =
282       static_cast<const PassManagerBuilderWrapper&>(Builder);
283   const Triple &T = BuilderWrapper.getTargetTriple();
284   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
285   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Address);
286   bool UseAfterScope = CGOpts.SanitizeAddressUseAfterScope;
287   bool UseOdrIndicator = CGOpts.SanitizeAddressUseOdrIndicator;
288   bool UseGlobalsGC = asanUseGlobalsGC(T, CGOpts);
289   llvm::AsanDtorKind DestructorKind = CGOpts.getSanitizeAddressDtorKind();
290   PM.add(createAddressSanitizerFunctionPass(/*CompileKernel*/ false, Recover,
291                                             UseAfterScope));
292   PM.add(createModuleAddressSanitizerLegacyPassPass(
293       /*CompileKernel*/ false, Recover, UseGlobalsGC, UseOdrIndicator,
294       DestructorKind));
295 }
296 
297 static void addKernelAddressSanitizerPasses(const PassManagerBuilder &Builder,
298                                             legacy::PassManagerBase &PM) {
299   PM.add(createAddressSanitizerFunctionPass(
300       /*CompileKernel*/ true, /*Recover*/ true, /*UseAfterScope*/ false));
301   PM.add(createModuleAddressSanitizerLegacyPassPass(
302       /*CompileKernel*/ true, /*Recover*/ true, /*UseGlobalsGC*/ true,
303       /*UseOdrIndicator*/ false));
304 }
305 
306 static void addHWAddressSanitizerPasses(const PassManagerBuilder &Builder,
307                                             legacy::PassManagerBase &PM) {
308   const PassManagerBuilderWrapper &BuilderWrapper =
309       static_cast<const PassManagerBuilderWrapper &>(Builder);
310   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
311   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::HWAddress);
312   PM.add(
313       createHWAddressSanitizerLegacyPassPass(/*CompileKernel*/ false, Recover));
314 }
315 
316 static void addKernelHWAddressSanitizerPasses(const PassManagerBuilder &Builder,
317                                             legacy::PassManagerBase &PM) {
318   PM.add(createHWAddressSanitizerLegacyPassPass(
319       /*CompileKernel*/ true, /*Recover*/ true));
320 }
321 
322 static void addGeneralOptsForMemorySanitizer(const PassManagerBuilder &Builder,
323                                              legacy::PassManagerBase &PM,
324                                              bool CompileKernel) {
325   const PassManagerBuilderWrapper &BuilderWrapper =
326       static_cast<const PassManagerBuilderWrapper&>(Builder);
327   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
328   int TrackOrigins = CGOpts.SanitizeMemoryTrackOrigins;
329   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Memory);
330   PM.add(createMemorySanitizerLegacyPassPass(
331       MemorySanitizerOptions{TrackOrigins, Recover, CompileKernel}));
332 
333   // MemorySanitizer inserts complex instrumentation that mostly follows
334   // the logic of the original code, but operates on "shadow" values.
335   // It can benefit from re-running some general purpose optimization passes.
336   if (Builder.OptLevel > 0) {
337     PM.add(createEarlyCSEPass());
338     PM.add(createReassociatePass());
339     PM.add(createLICMPass());
340     PM.add(createGVNPass());
341     PM.add(createInstructionCombiningPass());
342     PM.add(createDeadStoreEliminationPass());
343   }
344 }
345 
346 static void addMemorySanitizerPass(const PassManagerBuilder &Builder,
347                                    legacy::PassManagerBase &PM) {
348   addGeneralOptsForMemorySanitizer(Builder, PM, /*CompileKernel*/ false);
349 }
350 
351 static void addKernelMemorySanitizerPass(const PassManagerBuilder &Builder,
352                                          legacy::PassManagerBase &PM) {
353   addGeneralOptsForMemorySanitizer(Builder, PM, /*CompileKernel*/ true);
354 }
355 
356 static void addThreadSanitizerPass(const PassManagerBuilder &Builder,
357                                    legacy::PassManagerBase &PM) {
358   PM.add(createThreadSanitizerLegacyPassPass());
359 }
360 
361 static void addDataFlowSanitizerPass(const PassManagerBuilder &Builder,
362                                      legacy::PassManagerBase &PM) {
363   const PassManagerBuilderWrapper &BuilderWrapper =
364       static_cast<const PassManagerBuilderWrapper&>(Builder);
365   const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
366   PM.add(createDataFlowSanitizerLegacyPassPass(LangOpts.NoSanitizeFiles));
367 }
368 
369 static void addEntryExitInstrumentationPass(const PassManagerBuilder &Builder,
370                                             legacy::PassManagerBase &PM) {
371   PM.add(createEntryExitInstrumenterPass());
372 }
373 
374 static void
375 addPostInlineEntryExitInstrumentationPass(const PassManagerBuilder &Builder,
376                                           legacy::PassManagerBase &PM) {
377   PM.add(createPostInlineEntryExitInstrumenterPass());
378 }
379 
380 static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
381                                          const CodeGenOptions &CodeGenOpts) {
382   TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple);
383 
384   switch (CodeGenOpts.getVecLib()) {
385   case CodeGenOptions::Accelerate:
386     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::Accelerate);
387     break;
388   case CodeGenOptions::LIBMVEC:
389     switch(TargetTriple.getArch()) {
390       default:
391         break;
392       case llvm::Triple::x86_64:
393         TLII->addVectorizableFunctionsFromVecLib
394                 (TargetLibraryInfoImpl::LIBMVEC_X86);
395         break;
396     }
397     break;
398   case CodeGenOptions::MASSV:
399     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::MASSV);
400     break;
401   case CodeGenOptions::SVML:
402     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::SVML);
403     break;
404   default:
405     break;
406   }
407   return TLII;
408 }
409 
410 static void addSymbolRewriterPass(const CodeGenOptions &Opts,
411                                   legacy::PassManager *MPM) {
412   llvm::SymbolRewriter::RewriteDescriptorList DL;
413 
414   llvm::SymbolRewriter::RewriteMapParser MapParser;
415   for (const auto &MapFile : Opts.RewriteMapFiles)
416     MapParser.parse(MapFile, &DL);
417 
418   MPM->add(createRewriteSymbolsPass(DL));
419 }
420 
421 static CodeGenOpt::Level getCGOptLevel(const CodeGenOptions &CodeGenOpts) {
422   switch (CodeGenOpts.OptimizationLevel) {
423   default:
424     llvm_unreachable("Invalid optimization level!");
425   case 0:
426     return CodeGenOpt::None;
427   case 1:
428     return CodeGenOpt::Less;
429   case 2:
430     return CodeGenOpt::Default; // O2/Os/Oz
431   case 3:
432     return CodeGenOpt::Aggressive;
433   }
434 }
435 
436 static Optional<llvm::CodeModel::Model>
437 getCodeModel(const CodeGenOptions &CodeGenOpts) {
438   unsigned CodeModel = llvm::StringSwitch<unsigned>(CodeGenOpts.CodeModel)
439                            .Case("tiny", llvm::CodeModel::Tiny)
440                            .Case("small", llvm::CodeModel::Small)
441                            .Case("kernel", llvm::CodeModel::Kernel)
442                            .Case("medium", llvm::CodeModel::Medium)
443                            .Case("large", llvm::CodeModel::Large)
444                            .Case("default", ~1u)
445                            .Default(~0u);
446   assert(CodeModel != ~0u && "invalid code model!");
447   if (CodeModel == ~1u)
448     return None;
449   return static_cast<llvm::CodeModel::Model>(CodeModel);
450 }
451 
452 static CodeGenFileType getCodeGenFileType(BackendAction Action) {
453   if (Action == Backend_EmitObj)
454     return CGFT_ObjectFile;
455   else if (Action == Backend_EmitMCNull)
456     return CGFT_Null;
457   else {
458     assert(Action == Backend_EmitAssembly && "Invalid action!");
459     return CGFT_AssemblyFile;
460   }
461 }
462 
463 static bool initTargetOptions(DiagnosticsEngine &Diags,
464                               llvm::TargetOptions &Options,
465                               const CodeGenOptions &CodeGenOpts,
466                               const clang::TargetOptions &TargetOpts,
467                               const LangOptions &LangOpts,
468                               const HeaderSearchOptions &HSOpts) {
469   switch (LangOpts.getThreadModel()) {
470   case LangOptions::ThreadModelKind::POSIX:
471     Options.ThreadModel = llvm::ThreadModel::POSIX;
472     break;
473   case LangOptions::ThreadModelKind::Single:
474     Options.ThreadModel = llvm::ThreadModel::Single;
475     break;
476   }
477 
478   // Set float ABI type.
479   assert((CodeGenOpts.FloatABI == "soft" || CodeGenOpts.FloatABI == "softfp" ||
480           CodeGenOpts.FloatABI == "hard" || CodeGenOpts.FloatABI.empty()) &&
481          "Invalid Floating Point ABI!");
482   Options.FloatABIType =
483       llvm::StringSwitch<llvm::FloatABI::ABIType>(CodeGenOpts.FloatABI)
484           .Case("soft", llvm::FloatABI::Soft)
485           .Case("softfp", llvm::FloatABI::Soft)
486           .Case("hard", llvm::FloatABI::Hard)
487           .Default(llvm::FloatABI::Default);
488 
489   // Set FP fusion mode.
490   switch (LangOpts.getDefaultFPContractMode()) {
491   case LangOptions::FPM_Off:
492     // Preserve any contraction performed by the front-end.  (Strict performs
493     // splitting of the muladd intrinsic in the backend.)
494     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
495     break;
496   case LangOptions::FPM_On:
497   case LangOptions::FPM_FastHonorPragmas:
498     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
499     break;
500   case LangOptions::FPM_Fast:
501     Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
502     break;
503   }
504 
505   Options.BinutilsVersion =
506       llvm::TargetMachine::parseBinutilsVersion(CodeGenOpts.BinutilsVersion);
507   Options.UseInitArray = CodeGenOpts.UseInitArray;
508   Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
509   Options.CompressDebugSections = CodeGenOpts.getCompressDebugSections();
510   Options.RelaxELFRelocations = CodeGenOpts.RelaxELFRelocations;
511 
512   // Set EABI version.
513   Options.EABIVersion = TargetOpts.EABIVersion;
514 
515   if (LangOpts.hasSjLjExceptions())
516     Options.ExceptionModel = llvm::ExceptionHandling::SjLj;
517   if (LangOpts.hasSEHExceptions())
518     Options.ExceptionModel = llvm::ExceptionHandling::WinEH;
519   if (LangOpts.hasDWARFExceptions())
520     Options.ExceptionModel = llvm::ExceptionHandling::DwarfCFI;
521   if (LangOpts.hasWasmExceptions())
522     Options.ExceptionModel = llvm::ExceptionHandling::Wasm;
523 
524   Options.NoInfsFPMath = LangOpts.NoHonorInfs;
525   Options.NoNaNsFPMath = LangOpts.NoHonorNaNs;
526   Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
527   Options.UnsafeFPMath = LangOpts.UnsafeFPMath;
528   Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
529 
530   Options.BBSections =
531       llvm::StringSwitch<llvm::BasicBlockSection>(CodeGenOpts.BBSections)
532           .Case("all", llvm::BasicBlockSection::All)
533           .Case("labels", llvm::BasicBlockSection::Labels)
534           .StartsWith("list=", llvm::BasicBlockSection::List)
535           .Case("none", llvm::BasicBlockSection::None)
536           .Default(llvm::BasicBlockSection::None);
537 
538   if (Options.BBSections == llvm::BasicBlockSection::List) {
539     ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
540         MemoryBuffer::getFile(CodeGenOpts.BBSections.substr(5));
541     if (!MBOrErr) {
542       Diags.Report(diag::err_fe_unable_to_load_basic_block_sections_file)
543           << MBOrErr.getError().message();
544       return false;
545     }
546     Options.BBSectionsFuncListBuf = std::move(*MBOrErr);
547   }
548 
549   Options.EnableMachineFunctionSplitter = CodeGenOpts.SplitMachineFunctions;
550   Options.FunctionSections = CodeGenOpts.FunctionSections;
551   Options.DataSections = CodeGenOpts.DataSections;
552   Options.IgnoreXCOFFVisibility = LangOpts.IgnoreXCOFFVisibility;
553   Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
554   Options.UniqueBasicBlockSectionNames =
555       CodeGenOpts.UniqueBasicBlockSectionNames;
556   Options.StackProtectorGuard =
557       llvm::StringSwitch<llvm::StackProtectorGuards>(CodeGenOpts
558           .StackProtectorGuard)
559           .Case("tls", llvm::StackProtectorGuards::TLS)
560           .Case("global", llvm::StackProtectorGuards::Global)
561           .Default(llvm::StackProtectorGuards::None);
562   Options.StackProtectorGuardOffset = CodeGenOpts.StackProtectorGuardOffset;
563   Options.StackProtectorGuardReg = CodeGenOpts.StackProtectorGuardReg;
564   Options.TLSSize = CodeGenOpts.TLSSize;
565   Options.EmulatedTLS = CodeGenOpts.EmulatedTLS;
566   Options.ExplicitEmulatedTLS = CodeGenOpts.ExplicitEmulatedTLS;
567   Options.DebuggerTuning = CodeGenOpts.getDebuggerTuning();
568   Options.EmitStackSizeSection = CodeGenOpts.StackSizeSection;
569   Options.EmitAddrsig = CodeGenOpts.Addrsig;
570   Options.ForceDwarfFrameSection = CodeGenOpts.ForceDwarfFrameSection;
571   Options.EmitCallSiteInfo = CodeGenOpts.EmitCallSiteInfo;
572   Options.EnableAIXExtendedAltivecABI = CodeGenOpts.EnableAIXExtendedAltivecABI;
573   Options.PseudoProbeForProfiling = CodeGenOpts.PseudoProbeForProfiling;
574   Options.ValueTrackingVariableLocations =
575       CodeGenOpts.ValueTrackingVariableLocations;
576   Options.XRayOmitFunctionIndex = CodeGenOpts.XRayOmitFunctionIndex;
577 
578   Options.MCOptions.SplitDwarfFile = CodeGenOpts.SplitDwarfFile;
579   Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
580   Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
581   Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
582   Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
583   Options.MCOptions.MCIncrementalLinkerCompatible =
584       CodeGenOpts.IncrementalLinkerCompatible;
585   Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
586   Options.MCOptions.MCNoWarn = CodeGenOpts.NoWarn;
587   Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
588   Options.MCOptions.Dwarf64 = CodeGenOpts.Dwarf64;
589   Options.MCOptions.PreserveAsmComments = CodeGenOpts.PreserveAsmComments;
590   Options.MCOptions.ABIName = TargetOpts.ABI;
591   for (const auto &Entry : HSOpts.UserEntries)
592     if (!Entry.IsFramework &&
593         (Entry.Group == frontend::IncludeDirGroup::Quoted ||
594          Entry.Group == frontend::IncludeDirGroup::Angled ||
595          Entry.Group == frontend::IncludeDirGroup::System))
596       Options.MCOptions.IASSearchPaths.push_back(
597           Entry.IgnoreSysRoot ? Entry.Path : HSOpts.Sysroot + Entry.Path);
598   Options.MCOptions.Argv0 = CodeGenOpts.Argv0;
599   Options.MCOptions.CommandLineArgs = CodeGenOpts.CommandLineArgs;
600 
601   return true;
602 }
603 
604 static Optional<GCOVOptions> getGCOVOptions(const CodeGenOptions &CodeGenOpts,
605                                             const LangOptions &LangOpts) {
606   if (!CodeGenOpts.EmitGcovArcs && !CodeGenOpts.EmitGcovNotes)
607     return None;
608   // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
609   // LLVM's -default-gcov-version flag is set to something invalid.
610   GCOVOptions Options;
611   Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
612   Options.EmitData = CodeGenOpts.EmitGcovArcs;
613   llvm::copy(CodeGenOpts.CoverageVersion, std::begin(Options.Version));
614   Options.NoRedZone = CodeGenOpts.DisableRedZone;
615   Options.Filter = CodeGenOpts.ProfileFilterFiles;
616   Options.Exclude = CodeGenOpts.ProfileExcludeFiles;
617   Options.Atomic = CodeGenOpts.AtomicProfileUpdate;
618   return Options;
619 }
620 
621 static Optional<InstrProfOptions>
622 getInstrProfOptions(const CodeGenOptions &CodeGenOpts,
623                     const LangOptions &LangOpts) {
624   if (!CodeGenOpts.hasProfileClangInstr())
625     return None;
626   InstrProfOptions Options;
627   Options.NoRedZone = CodeGenOpts.DisableRedZone;
628   Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
629   Options.Atomic = CodeGenOpts.AtomicProfileUpdate;
630   return Options;
631 }
632 
633 void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
634                                       legacy::FunctionPassManager &FPM) {
635   // Handle disabling of all LLVM passes, where we want to preserve the
636   // internal module before any optimization.
637   if (CodeGenOpts.DisableLLVMPasses)
638     return;
639 
640   // Figure out TargetLibraryInfo.  This needs to be added to MPM and FPM
641   // manually (and not via PMBuilder), since some passes (eg. InstrProfiling)
642   // are inserted before PMBuilder ones - they'd get the default-constructed
643   // TLI with an unknown target otherwise.
644   Triple TargetTriple(TheModule->getTargetTriple());
645   std::unique_ptr<TargetLibraryInfoImpl> TLII(
646       createTLII(TargetTriple, CodeGenOpts));
647 
648   // If we reached here with a non-empty index file name, then the index file
649   // was empty and we are not performing ThinLTO backend compilation (used in
650   // testing in a distributed build environment). Drop any the type test
651   // assume sequences inserted for whole program vtables so that codegen doesn't
652   // complain.
653   if (!CodeGenOpts.ThinLTOIndexFile.empty())
654     MPM.add(createLowerTypeTestsPass(/*ExportSummary=*/nullptr,
655                                      /*ImportSummary=*/nullptr,
656                                      /*DropTypeTests=*/true));
657 
658   PassManagerBuilderWrapper PMBuilder(TargetTriple, CodeGenOpts, LangOpts);
659 
660   // At O0 and O1 we only run the always inliner which is more efficient. At
661   // higher optimization levels we run the normal inliner.
662   if (CodeGenOpts.OptimizationLevel <= 1) {
663     bool InsertLifetimeIntrinsics = ((CodeGenOpts.OptimizationLevel != 0 &&
664                                       !CodeGenOpts.DisableLifetimeMarkers) ||
665                                      LangOpts.Coroutines);
666     PMBuilder.Inliner = createAlwaysInlinerLegacyPass(InsertLifetimeIntrinsics);
667   } else {
668     // We do not want to inline hot callsites for SamplePGO module-summary build
669     // because profile annotation will happen again in ThinLTO backend, and we
670     // want the IR of the hot path to match the profile.
671     PMBuilder.Inliner = createFunctionInliningPass(
672         CodeGenOpts.OptimizationLevel, CodeGenOpts.OptimizeSize,
673         (!CodeGenOpts.SampleProfileFile.empty() &&
674          CodeGenOpts.PrepareForThinLTO));
675   }
676 
677   PMBuilder.OptLevel = CodeGenOpts.OptimizationLevel;
678   PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
679   PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
680   PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
681   // Only enable CGProfilePass when using integrated assembler, since
682   // non-integrated assemblers don't recognize .cgprofile section.
683   PMBuilder.CallGraphProfile = !CodeGenOpts.DisableIntegratedAS;
684 
685   PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
686   // Loop interleaving in the loop vectorizer has historically been set to be
687   // enabled when loop unrolling is enabled.
688   PMBuilder.LoopsInterleaved = CodeGenOpts.UnrollLoops;
689   PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
690   PMBuilder.PrepareForThinLTO = CodeGenOpts.PrepareForThinLTO;
691   PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
692   PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
693 
694   MPM.add(new TargetLibraryInfoWrapperPass(*TLII));
695 
696   if (TM)
697     TM->adjustPassManager(PMBuilder);
698 
699   if (CodeGenOpts.DebugInfoForProfiling ||
700       !CodeGenOpts.SampleProfileFile.empty())
701     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
702                            addAddDiscriminatorsPass);
703 
704   // In ObjC ARC mode, add the main ARC optimization passes.
705   if (LangOpts.ObjCAutoRefCount) {
706     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
707                            addObjCARCExpandPass);
708     PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
709                            addObjCARCAPElimPass);
710     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
711                            addObjCARCOptPass);
712   }
713 
714   if (LangOpts.Coroutines)
715     addCoroutinePassesToExtensionPoints(PMBuilder);
716 
717   if (!CodeGenOpts.MemoryProfileOutput.empty()) {
718     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
719                            addMemProfilerPasses);
720     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
721                            addMemProfilerPasses);
722   }
723 
724   if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds)) {
725     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
726                            addBoundsCheckingPass);
727     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
728                            addBoundsCheckingPass);
729   }
730 
731   if (CodeGenOpts.SanitizeCoverageType ||
732       CodeGenOpts.SanitizeCoverageIndirectCalls ||
733       CodeGenOpts.SanitizeCoverageTraceCmp) {
734     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
735                            addSanitizerCoveragePass);
736     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
737                            addSanitizerCoveragePass);
738   }
739 
740   if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
741     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
742                            addAddressSanitizerPasses);
743     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
744                            addAddressSanitizerPasses);
745   }
746 
747   if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
748     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
749                            addKernelAddressSanitizerPasses);
750     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
751                            addKernelAddressSanitizerPasses);
752   }
753 
754   if (LangOpts.Sanitize.has(SanitizerKind::HWAddress)) {
755     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
756                            addHWAddressSanitizerPasses);
757     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
758                            addHWAddressSanitizerPasses);
759   }
760 
761   if (LangOpts.Sanitize.has(SanitizerKind::KernelHWAddress)) {
762     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
763                            addKernelHWAddressSanitizerPasses);
764     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
765                            addKernelHWAddressSanitizerPasses);
766   }
767 
768   if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
769     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
770                            addMemorySanitizerPass);
771     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
772                            addMemorySanitizerPass);
773   }
774 
775   if (LangOpts.Sanitize.has(SanitizerKind::KernelMemory)) {
776     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
777                            addKernelMemorySanitizerPass);
778     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
779                            addKernelMemorySanitizerPass);
780   }
781 
782   if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
783     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
784                            addThreadSanitizerPass);
785     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
786                            addThreadSanitizerPass);
787   }
788 
789   if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
790     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
791                            addDataFlowSanitizerPass);
792     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
793                            addDataFlowSanitizerPass);
794   }
795 
796   if (CodeGenOpts.InstrumentFunctions ||
797       CodeGenOpts.InstrumentFunctionEntryBare ||
798       CodeGenOpts.InstrumentFunctionsAfterInlining ||
799       CodeGenOpts.InstrumentForProfiling) {
800     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
801                            addEntryExitInstrumentationPass);
802     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
803                            addEntryExitInstrumentationPass);
804     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
805                            addPostInlineEntryExitInstrumentationPass);
806     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
807                            addPostInlineEntryExitInstrumentationPass);
808   }
809 
810   // Set up the per-function pass manager.
811   FPM.add(new TargetLibraryInfoWrapperPass(*TLII));
812   if (CodeGenOpts.VerifyModule)
813     FPM.add(createVerifierPass());
814 
815   // Set up the per-module pass manager.
816   if (!CodeGenOpts.RewriteMapFiles.empty())
817     addSymbolRewriterPass(CodeGenOpts, &MPM);
818 
819   if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts, LangOpts)) {
820     MPM.add(createGCOVProfilerPass(*Options));
821     if (CodeGenOpts.getDebugInfo() == codegenoptions::NoDebugInfo)
822       MPM.add(createStripSymbolsPass(true));
823   }
824 
825   if (Optional<InstrProfOptions> Options =
826           getInstrProfOptions(CodeGenOpts, LangOpts))
827     MPM.add(createInstrProfilingLegacyPass(*Options, false));
828 
829   bool hasIRInstr = false;
830   if (CodeGenOpts.hasProfileIRInstr()) {
831     PMBuilder.EnablePGOInstrGen = true;
832     hasIRInstr = true;
833   }
834   if (CodeGenOpts.hasProfileCSIRInstr()) {
835     assert(!CodeGenOpts.hasProfileCSIRUse() &&
836            "Cannot have both CSProfileUse pass and CSProfileGen pass at the "
837            "same time");
838     assert(!hasIRInstr &&
839            "Cannot have both ProfileGen pass and CSProfileGen pass at the "
840            "same time");
841     PMBuilder.EnablePGOCSInstrGen = true;
842     hasIRInstr = true;
843   }
844   if (hasIRInstr) {
845     if (!CodeGenOpts.InstrProfileOutput.empty())
846       PMBuilder.PGOInstrGen = CodeGenOpts.InstrProfileOutput;
847     else
848       PMBuilder.PGOInstrGen = std::string(DefaultProfileGenName);
849   }
850   if (CodeGenOpts.hasProfileIRUse()) {
851     PMBuilder.PGOInstrUse = CodeGenOpts.ProfileInstrumentUsePath;
852     PMBuilder.EnablePGOCSInstrUse = CodeGenOpts.hasProfileCSIRUse();
853   }
854 
855   if (!CodeGenOpts.SampleProfileFile.empty())
856     PMBuilder.PGOSampleUse = CodeGenOpts.SampleProfileFile;
857 
858   PMBuilder.populateFunctionPassManager(FPM);
859   PMBuilder.populateModulePassManager(MPM);
860 }
861 
862 static void setCommandLineOpts(const CodeGenOptions &CodeGenOpts) {
863   SmallVector<const char *, 16> BackendArgs;
864   BackendArgs.push_back("clang"); // Fake program name.
865   if (!CodeGenOpts.DebugPass.empty()) {
866     BackendArgs.push_back("-debug-pass");
867     BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
868   }
869   if (!CodeGenOpts.LimitFloatPrecision.empty()) {
870     BackendArgs.push_back("-limit-float-precision");
871     BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
872   }
873   BackendArgs.push_back(nullptr);
874   llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
875                                     BackendArgs.data());
876 }
877 
878 void EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
879   // Create the TargetMachine for generating code.
880   std::string Error;
881   std::string Triple = TheModule->getTargetTriple();
882   const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
883   if (!TheTarget) {
884     if (MustCreateTM)
885       Diags.Report(diag::err_fe_unable_to_create_target) << Error;
886     return;
887   }
888 
889   Optional<llvm::CodeModel::Model> CM = getCodeModel(CodeGenOpts);
890   std::string FeaturesStr =
891       llvm::join(TargetOpts.Features.begin(), TargetOpts.Features.end(), ",");
892   llvm::Reloc::Model RM = CodeGenOpts.RelocationModel;
893   CodeGenOpt::Level OptLevel = getCGOptLevel(CodeGenOpts);
894 
895   llvm::TargetOptions Options;
896   if (!initTargetOptions(Diags, Options, CodeGenOpts, TargetOpts, LangOpts,
897                          HSOpts))
898     return;
899   TM.reset(TheTarget->createTargetMachine(Triple, TargetOpts.CPU, FeaturesStr,
900                                           Options, RM, CM, OptLevel));
901 }
902 
903 bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
904                                        BackendAction Action,
905                                        raw_pwrite_stream &OS,
906                                        raw_pwrite_stream *DwoOS) {
907   // Add LibraryInfo.
908   llvm::Triple TargetTriple(TheModule->getTargetTriple());
909   std::unique_ptr<TargetLibraryInfoImpl> TLII(
910       createTLII(TargetTriple, CodeGenOpts));
911   CodeGenPasses.add(new TargetLibraryInfoWrapperPass(*TLII));
912 
913   // Normal mode, emit a .s or .o file by running the code generator. Note,
914   // this also adds codegenerator level optimization passes.
915   CodeGenFileType CGFT = getCodeGenFileType(Action);
916 
917   // Add ObjC ARC final-cleanup optimizations. This is done as part of the
918   // "codegen" passes so that it isn't run multiple times when there is
919   // inlining happening.
920   if (CodeGenOpts.OptimizationLevel > 0)
921     CodeGenPasses.add(createObjCARCContractPass());
922 
923   if (TM->addPassesToEmitFile(CodeGenPasses, OS, DwoOS, CGFT,
924                               /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
925     Diags.Report(diag::err_fe_unable_to_interface_with_target);
926     return false;
927   }
928 
929   return true;
930 }
931 
932 void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
933                                       std::unique_ptr<raw_pwrite_stream> OS) {
934   TimeRegion Region(CodeGenOpts.TimePasses ? &CodeGenerationTime : nullptr);
935 
936   setCommandLineOpts(CodeGenOpts);
937 
938   bool UsesCodeGen = (Action != Backend_EmitNothing &&
939                       Action != Backend_EmitBC &&
940                       Action != Backend_EmitLL);
941   CreateTargetMachine(UsesCodeGen);
942 
943   if (UsesCodeGen && !TM)
944     return;
945   if (TM)
946     TheModule->setDataLayout(TM->createDataLayout());
947 
948   legacy::PassManager PerModulePasses;
949   PerModulePasses.add(
950       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
951 
952   legacy::FunctionPassManager PerFunctionPasses(TheModule);
953   PerFunctionPasses.add(
954       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
955 
956   CreatePasses(PerModulePasses, PerFunctionPasses);
957 
958   legacy::PassManager CodeGenPasses;
959   CodeGenPasses.add(
960       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
961 
962   std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
963 
964   switch (Action) {
965   case Backend_EmitNothing:
966     break;
967 
968   case Backend_EmitBC:
969     if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
970       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
971         ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
972         if (!ThinLinkOS)
973           return;
974       }
975       TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
976                                CodeGenOpts.EnableSplitLTOUnit);
977       PerModulePasses.add(createWriteThinLTOBitcodePass(
978           *OS, ThinLinkOS ? &ThinLinkOS->os() : nullptr));
979     } else {
980       // Emit a module summary by default for Regular LTO except for ld64
981       // targets
982       bool EmitLTOSummary =
983           (CodeGenOpts.PrepareForLTO &&
984            !CodeGenOpts.DisableLLVMPasses &&
985            llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
986                llvm::Triple::Apple);
987       if (EmitLTOSummary) {
988         if (!TheModule->getModuleFlag("ThinLTO"))
989           TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
990         TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
991                                  uint32_t(1));
992       }
993 
994       PerModulePasses.add(createBitcodeWriterPass(
995           *OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
996     }
997     break;
998 
999   case Backend_EmitLL:
1000     PerModulePasses.add(
1001         createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
1002     break;
1003 
1004   default:
1005     if (!CodeGenOpts.SplitDwarfOutput.empty()) {
1006       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
1007       if (!DwoOS)
1008         return;
1009     }
1010     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
1011                        DwoOS ? &DwoOS->os() : nullptr))
1012       return;
1013   }
1014 
1015   // Before executing passes, print the final values of the LLVM options.
1016   cl::PrintOptionValues();
1017 
1018   // Run passes. For now we do all passes at once, but eventually we
1019   // would like to have the option of streaming code generation.
1020 
1021   {
1022     PrettyStackTraceString CrashInfo("Per-function optimization");
1023     llvm::TimeTraceScope TimeScope("PerFunctionPasses");
1024 
1025     PerFunctionPasses.doInitialization();
1026     for (Function &F : *TheModule)
1027       if (!F.isDeclaration())
1028         PerFunctionPasses.run(F);
1029     PerFunctionPasses.doFinalization();
1030   }
1031 
1032   {
1033     PrettyStackTraceString CrashInfo("Per-module optimization passes");
1034     llvm::TimeTraceScope TimeScope("PerModulePasses");
1035     PerModulePasses.run(*TheModule);
1036   }
1037 
1038   {
1039     PrettyStackTraceString CrashInfo("Code generation");
1040     llvm::TimeTraceScope TimeScope("CodeGenPasses");
1041     CodeGenPasses.run(*TheModule);
1042   }
1043 
1044   if (ThinLinkOS)
1045     ThinLinkOS->keep();
1046   if (DwoOS)
1047     DwoOS->keep();
1048 }
1049 
1050 static PassBuilder::OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
1051   switch (Opts.OptimizationLevel) {
1052   default:
1053     llvm_unreachable("Invalid optimization level!");
1054 
1055   case 0:
1056     return PassBuilder::OptimizationLevel::O0;
1057 
1058   case 1:
1059     return PassBuilder::OptimizationLevel::O1;
1060 
1061   case 2:
1062     switch (Opts.OptimizeSize) {
1063     default:
1064       llvm_unreachable("Invalid optimization level for size!");
1065 
1066     case 0:
1067       return PassBuilder::OptimizationLevel::O2;
1068 
1069     case 1:
1070       return PassBuilder::OptimizationLevel::Os;
1071 
1072     case 2:
1073       return PassBuilder::OptimizationLevel::Oz;
1074     }
1075 
1076   case 3:
1077     return PassBuilder::OptimizationLevel::O3;
1078   }
1079 }
1080 
1081 static void addSanitizers(const Triple &TargetTriple,
1082                           const CodeGenOptions &CodeGenOpts,
1083                           const LangOptions &LangOpts, PassBuilder &PB) {
1084   PB.registerOptimizerLastEPCallback([&](ModulePassManager &MPM,
1085                                          PassBuilder::OptimizationLevel Level) {
1086     if (CodeGenOpts.SanitizeCoverageType ||
1087         CodeGenOpts.SanitizeCoverageIndirectCalls ||
1088         CodeGenOpts.SanitizeCoverageTraceCmp) {
1089       auto SancovOpts = getSancovOptsFromCGOpts(CodeGenOpts);
1090       MPM.addPass(ModuleSanitizerCoveragePass(
1091           SancovOpts, CodeGenOpts.SanitizeCoverageAllowlistFiles,
1092           CodeGenOpts.SanitizeCoverageBlocklistFiles));
1093     }
1094 
1095     auto MSanPass = [&](SanitizerMask Mask, bool CompileKernel) {
1096       if (LangOpts.Sanitize.has(Mask)) {
1097         int TrackOrigins = CodeGenOpts.SanitizeMemoryTrackOrigins;
1098         bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
1099 
1100         MPM.addPass(
1101             MemorySanitizerPass({TrackOrigins, Recover, CompileKernel}));
1102         FunctionPassManager FPM(CodeGenOpts.DebugPassManager);
1103         FPM.addPass(
1104             MemorySanitizerPass({TrackOrigins, Recover, CompileKernel}));
1105         if (Level != PassBuilder::OptimizationLevel::O0) {
1106           // MemorySanitizer inserts complex instrumentation that mostly
1107           // follows the logic of the original code, but operates on
1108           // "shadow" values. It can benefit from re-running some
1109           // general purpose optimization passes.
1110           FPM.addPass(EarlyCSEPass());
1111           // TODO: Consider add more passes like in
1112           // addGeneralOptsForMemorySanitizer. EarlyCSEPass makes visible
1113           // difference on size. It's not clear if the rest is still
1114           // usefull. InstCombinePass breakes
1115           // compiler-rt/test/msan/select_origin.cpp.
1116         }
1117         MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
1118       }
1119     };
1120     MSanPass(SanitizerKind::Memory, false);
1121     MSanPass(SanitizerKind::KernelMemory, true);
1122 
1123     if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
1124       MPM.addPass(ThreadSanitizerPass());
1125       MPM.addPass(createModuleToFunctionPassAdaptor(ThreadSanitizerPass()));
1126     }
1127 
1128     auto ASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
1129       if (LangOpts.Sanitize.has(Mask)) {
1130         bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
1131         bool UseAfterScope = CodeGenOpts.SanitizeAddressUseAfterScope;
1132         bool ModuleUseAfterScope = asanUseGlobalsGC(TargetTriple, CodeGenOpts);
1133         bool UseOdrIndicator = CodeGenOpts.SanitizeAddressUseOdrIndicator;
1134         llvm::AsanDtorKind DestructorKind =
1135             CodeGenOpts.getSanitizeAddressDtorKind();
1136         MPM.addPass(RequireAnalysisPass<ASanGlobalsMetadataAnalysis, Module>());
1137         MPM.addPass(ModuleAddressSanitizerPass(
1138             CompileKernel, Recover, ModuleUseAfterScope, UseOdrIndicator,
1139             DestructorKind));
1140         MPM.addPass(createModuleToFunctionPassAdaptor(
1141             AddressSanitizerPass(CompileKernel, Recover, UseAfterScope)));
1142       }
1143     };
1144     ASanPass(SanitizerKind::Address, false);
1145     ASanPass(SanitizerKind::KernelAddress, true);
1146 
1147     auto HWASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
1148       if (LangOpts.Sanitize.has(Mask)) {
1149         bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
1150         MPM.addPass(HWAddressSanitizerPass(CompileKernel, Recover));
1151       }
1152     };
1153     HWASanPass(SanitizerKind::HWAddress, false);
1154     HWASanPass(SanitizerKind::KernelHWAddress, true);
1155 
1156     if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
1157       MPM.addPass(DataFlowSanitizerPass(LangOpts.NoSanitizeFiles));
1158     }
1159   });
1160 }
1161 
1162 /// A clean version of `EmitAssembly` that uses the new pass manager.
1163 ///
1164 /// Not all features are currently supported in this system, but where
1165 /// necessary it falls back to the legacy pass manager to at least provide
1166 /// basic functionality.
1167 ///
1168 /// This API is planned to have its functionality finished and then to replace
1169 /// `EmitAssembly` at some point in the future when the default switches.
1170 void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
1171     BackendAction Action, std::unique_ptr<raw_pwrite_stream> OS) {
1172   TimeRegion Region(CodeGenOpts.TimePasses ? &CodeGenerationTime : nullptr);
1173   setCommandLineOpts(CodeGenOpts);
1174 
1175   bool RequiresCodeGen = (Action != Backend_EmitNothing &&
1176                           Action != Backend_EmitBC &&
1177                           Action != Backend_EmitLL);
1178   CreateTargetMachine(RequiresCodeGen);
1179 
1180   if (RequiresCodeGen && !TM)
1181     return;
1182   if (TM)
1183     TheModule->setDataLayout(TM->createDataLayout());
1184 
1185   Optional<PGOOptions> PGOOpt;
1186 
1187   if (CodeGenOpts.hasProfileIRInstr())
1188     // -fprofile-generate.
1189     PGOOpt = PGOOptions(CodeGenOpts.InstrProfileOutput.empty()
1190                             ? std::string(DefaultProfileGenName)
1191                             : CodeGenOpts.InstrProfileOutput,
1192                         "", "", PGOOptions::IRInstr, PGOOptions::NoCSAction,
1193                         CodeGenOpts.DebugInfoForProfiling);
1194   else if (CodeGenOpts.hasProfileIRUse()) {
1195     // -fprofile-use.
1196     auto CSAction = CodeGenOpts.hasProfileCSIRUse() ? PGOOptions::CSIRUse
1197                                                     : PGOOptions::NoCSAction;
1198     PGOOpt = PGOOptions(CodeGenOpts.ProfileInstrumentUsePath, "",
1199                         CodeGenOpts.ProfileRemappingFile, PGOOptions::IRUse,
1200                         CSAction, CodeGenOpts.DebugInfoForProfiling);
1201   } else if (!CodeGenOpts.SampleProfileFile.empty())
1202     // -fprofile-sample-use
1203     PGOOpt = PGOOptions(
1204         CodeGenOpts.SampleProfileFile, "", CodeGenOpts.ProfileRemappingFile,
1205         PGOOptions::SampleUse, PGOOptions::NoCSAction,
1206         CodeGenOpts.DebugInfoForProfiling, CodeGenOpts.PseudoProbeForProfiling);
1207   else if (CodeGenOpts.PseudoProbeForProfiling)
1208     // -fpseudo-probe-for-profiling
1209     PGOOpt =
1210         PGOOptions("", "", "", PGOOptions::NoAction, PGOOptions::NoCSAction,
1211                    CodeGenOpts.DebugInfoForProfiling, true);
1212   else if (CodeGenOpts.DebugInfoForProfiling)
1213     // -fdebug-info-for-profiling
1214     PGOOpt = PGOOptions("", "", "", PGOOptions::NoAction,
1215                         PGOOptions::NoCSAction, true);
1216 
1217   // Check to see if we want to generate a CS profile.
1218   if (CodeGenOpts.hasProfileCSIRInstr()) {
1219     assert(!CodeGenOpts.hasProfileCSIRUse() &&
1220            "Cannot have both CSProfileUse pass and CSProfileGen pass at "
1221            "the same time");
1222     if (PGOOpt.hasValue()) {
1223       assert(PGOOpt->Action != PGOOptions::IRInstr &&
1224              PGOOpt->Action != PGOOptions::SampleUse &&
1225              "Cannot run CSProfileGen pass with ProfileGen or SampleUse "
1226              " pass");
1227       PGOOpt->CSProfileGenFile = CodeGenOpts.InstrProfileOutput.empty()
1228                                      ? std::string(DefaultProfileGenName)
1229                                      : CodeGenOpts.InstrProfileOutput;
1230       PGOOpt->CSAction = PGOOptions::CSIRInstr;
1231     } else
1232       PGOOpt = PGOOptions("",
1233                           CodeGenOpts.InstrProfileOutput.empty()
1234                               ? std::string(DefaultProfileGenName)
1235                               : CodeGenOpts.InstrProfileOutput,
1236                           "", PGOOptions::NoAction, PGOOptions::CSIRInstr,
1237                           CodeGenOpts.DebugInfoForProfiling);
1238   }
1239 
1240   PipelineTuningOptions PTO;
1241   PTO.LoopUnrolling = CodeGenOpts.UnrollLoops;
1242   // For historical reasons, loop interleaving is set to mirror setting for loop
1243   // unrolling.
1244   PTO.LoopInterleaving = CodeGenOpts.UnrollLoops;
1245   PTO.LoopVectorization = CodeGenOpts.VectorizeLoop;
1246   PTO.SLPVectorization = CodeGenOpts.VectorizeSLP;
1247   PTO.MergeFunctions = CodeGenOpts.MergeFunctions;
1248   // Only enable CGProfilePass when using integrated assembler, since
1249   // non-integrated assemblers don't recognize .cgprofile section.
1250   PTO.CallGraphProfile = !CodeGenOpts.DisableIntegratedAS;
1251   PTO.Coroutines = LangOpts.Coroutines;
1252 
1253   PassInstrumentationCallbacks PIC;
1254   StandardInstrumentations SI(CodeGenOpts.DebugPassManager);
1255   SI.registerCallbacks(PIC);
1256   PassBuilder PB(CodeGenOpts.DebugPassManager, TM.get(), PTO, PGOOpt, &PIC);
1257 
1258   // Attempt to load pass plugins and register their callbacks with PB.
1259   for (auto &PluginFN : CodeGenOpts.PassPlugins) {
1260     auto PassPlugin = PassPlugin::Load(PluginFN);
1261     if (PassPlugin) {
1262       PassPlugin->registerPassBuilderCallbacks(PB);
1263     } else {
1264       Diags.Report(diag::err_fe_unable_to_load_plugin)
1265           << PluginFN << toString(PassPlugin.takeError());
1266     }
1267   }
1268 #define HANDLE_EXTENSION(Ext)                                                  \
1269   get##Ext##PluginInfo().RegisterPassBuilderCallbacks(PB);
1270 #include "llvm/Support/Extension.def"
1271 
1272   LoopAnalysisManager LAM(CodeGenOpts.DebugPassManager);
1273   FunctionAnalysisManager FAM(CodeGenOpts.DebugPassManager);
1274   CGSCCAnalysisManager CGAM(CodeGenOpts.DebugPassManager);
1275   ModuleAnalysisManager MAM(CodeGenOpts.DebugPassManager);
1276 
1277   // Register the AA manager first so that our version is the one used.
1278   FAM.registerPass([&] { return PB.buildDefaultAAPipeline(); });
1279 
1280   // Register the target library analysis directly and give it a customized
1281   // preset TLI.
1282   Triple TargetTriple(TheModule->getTargetTriple());
1283   std::unique_ptr<TargetLibraryInfoImpl> TLII(
1284       createTLII(TargetTriple, CodeGenOpts));
1285   FAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); });
1286 
1287   // Register all the basic analyses with the managers.
1288   PB.registerModuleAnalyses(MAM);
1289   PB.registerCGSCCAnalyses(CGAM);
1290   PB.registerFunctionAnalyses(FAM);
1291   PB.registerLoopAnalyses(LAM);
1292   PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
1293 
1294   ModulePassManager MPM(CodeGenOpts.DebugPassManager);
1295 
1296   if (!CodeGenOpts.DisableLLVMPasses) {
1297     // Map our optimization levels into one of the distinct levels used to
1298     // configure the pipeline.
1299     PassBuilder::OptimizationLevel Level = mapToLevel(CodeGenOpts);
1300 
1301     bool IsThinLTO = CodeGenOpts.PrepareForThinLTO;
1302     bool IsLTO = CodeGenOpts.PrepareForLTO;
1303 
1304     if (LangOpts.ObjCAutoRefCount) {
1305       PB.registerPipelineStartEPCallback(
1306           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1307             if (Level != PassBuilder::OptimizationLevel::O0)
1308               MPM.addPass(
1309                   createModuleToFunctionPassAdaptor(ObjCARCExpandPass()));
1310           });
1311       PB.registerPipelineEarlySimplificationEPCallback(
1312           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1313             if (Level != PassBuilder::OptimizationLevel::O0)
1314               MPM.addPass(ObjCARCAPElimPass());
1315           });
1316       PB.registerScalarOptimizerLateEPCallback(
1317           [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
1318             if (Level != PassBuilder::OptimizationLevel::O0)
1319               FPM.addPass(ObjCARCOptPass());
1320           });
1321     }
1322 
1323     // If we reached here with a non-empty index file name, then the index
1324     // file was empty and we are not performing ThinLTO backend compilation
1325     // (used in testing in a distributed build environment).
1326     bool IsThinLTOPostLink = !CodeGenOpts.ThinLTOIndexFile.empty();
1327     // If so drop any the type test assume sequences inserted for whole program
1328     // vtables so that codegen doesn't complain.
1329     if (IsThinLTOPostLink)
1330       PB.registerPipelineStartEPCallback(
1331           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1332             MPM.addPass(LowerTypeTestsPass(/*ExportSummary=*/nullptr,
1333                                            /*ImportSummary=*/nullptr,
1334                                            /*DropTypeTests=*/true));
1335           });
1336 
1337     if (CodeGenOpts.InstrumentFunctions ||
1338         CodeGenOpts.InstrumentFunctionEntryBare ||
1339         CodeGenOpts.InstrumentFunctionsAfterInlining ||
1340         CodeGenOpts.InstrumentForProfiling) {
1341       PB.registerPipelineStartEPCallback(
1342           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1343             MPM.addPass(createModuleToFunctionPassAdaptor(
1344                 EntryExitInstrumenterPass(/*PostInlining=*/false)));
1345           });
1346       PB.registerOptimizerLastEPCallback(
1347           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1348             MPM.addPass(createModuleToFunctionPassAdaptor(
1349                 EntryExitInstrumenterPass(/*PostInlining=*/true)));
1350           });
1351     }
1352 
1353     // Register callbacks to schedule sanitizer passes at the appropriate part
1354     // of the pipeline.
1355     if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
1356       PB.registerScalarOptimizerLateEPCallback(
1357           [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
1358             FPM.addPass(BoundsCheckingPass());
1359           });
1360 
1361     // Don't add sanitizers if we are here from ThinLTO PostLink. That already
1362     // done on PreLink stage.
1363     if (!IsThinLTOPostLink)
1364       addSanitizers(TargetTriple, CodeGenOpts, LangOpts, PB);
1365 
1366     if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts, LangOpts))
1367       PB.registerPipelineStartEPCallback(
1368           [Options](ModulePassManager &MPM,
1369                     PassBuilder::OptimizationLevel Level) {
1370             MPM.addPass(GCOVProfilerPass(*Options));
1371           });
1372     if (Optional<InstrProfOptions> Options =
1373             getInstrProfOptions(CodeGenOpts, LangOpts))
1374       PB.registerPipelineStartEPCallback(
1375           [Options](ModulePassManager &MPM,
1376                     PassBuilder::OptimizationLevel Level) {
1377             MPM.addPass(InstrProfiling(*Options, false));
1378           });
1379 
1380     if (CodeGenOpts.OptimizationLevel == 0) {
1381       MPM = PB.buildO0DefaultPipeline(Level, IsLTO || IsThinLTO);
1382     } else if (IsThinLTO) {
1383       MPM = PB.buildThinLTOPreLinkDefaultPipeline(Level);
1384     } else if (IsLTO) {
1385       MPM = PB.buildLTOPreLinkDefaultPipeline(Level);
1386     } else {
1387       MPM = PB.buildPerModuleDefaultPipeline(Level);
1388     }
1389 
1390     if (!CodeGenOpts.MemoryProfileOutput.empty()) {
1391       MPM.addPass(createModuleToFunctionPassAdaptor(MemProfilerPass()));
1392       MPM.addPass(ModuleMemProfilerPass());
1393     }
1394   }
1395 
1396   // FIXME: We still use the legacy pass manager to do code generation. We
1397   // create that pass manager here and use it as needed below.
1398   legacy::PassManager CodeGenPasses;
1399   bool NeedCodeGen = false;
1400   std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
1401 
1402   // Append any output we need to the pass manager.
1403   switch (Action) {
1404   case Backend_EmitNothing:
1405     break;
1406 
1407   case Backend_EmitBC:
1408     if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
1409       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
1410         ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
1411         if (!ThinLinkOS)
1412           return;
1413       }
1414       TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1415                                CodeGenOpts.EnableSplitLTOUnit);
1416       MPM.addPass(ThinLTOBitcodeWriterPass(*OS, ThinLinkOS ? &ThinLinkOS->os()
1417                                                            : nullptr));
1418     } else {
1419       // Emit a module summary by default for Regular LTO except for ld64
1420       // targets
1421       bool EmitLTOSummary =
1422           (CodeGenOpts.PrepareForLTO &&
1423            !CodeGenOpts.DisableLLVMPasses &&
1424            llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
1425                llvm::Triple::Apple);
1426       if (EmitLTOSummary) {
1427         if (!TheModule->getModuleFlag("ThinLTO"))
1428           TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
1429         TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1430                                  uint32_t(1));
1431       }
1432       MPM.addPass(
1433           BitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
1434     }
1435     break;
1436 
1437   case Backend_EmitLL:
1438     MPM.addPass(PrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
1439     break;
1440 
1441   case Backend_EmitAssembly:
1442   case Backend_EmitMCNull:
1443   case Backend_EmitObj:
1444     NeedCodeGen = true;
1445     CodeGenPasses.add(
1446         createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
1447     if (!CodeGenOpts.SplitDwarfOutput.empty()) {
1448       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
1449       if (!DwoOS)
1450         return;
1451     }
1452     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
1453                        DwoOS ? &DwoOS->os() : nullptr))
1454       // FIXME: Should we handle this error differently?
1455       return;
1456     break;
1457   }
1458 
1459   // Before executing passes, print the final values of the LLVM options.
1460   cl::PrintOptionValues();
1461 
1462   // Now that we have all of the passes ready, run them.
1463   {
1464     PrettyStackTraceString CrashInfo("Optimizer");
1465     MPM.run(*TheModule, MAM);
1466   }
1467 
1468   // Now if needed, run the legacy PM for codegen.
1469   if (NeedCodeGen) {
1470     PrettyStackTraceString CrashInfo("Code generation");
1471     CodeGenPasses.run(*TheModule);
1472   }
1473 
1474   if (ThinLinkOS)
1475     ThinLinkOS->keep();
1476   if (DwoOS)
1477     DwoOS->keep();
1478 }
1479 
1480 static void runThinLTOBackend(
1481     DiagnosticsEngine &Diags, ModuleSummaryIndex *CombinedIndex, Module *M,
1482     const HeaderSearchOptions &HeaderOpts, const CodeGenOptions &CGOpts,
1483     const clang::TargetOptions &TOpts, const LangOptions &LOpts,
1484     std::unique_ptr<raw_pwrite_stream> OS, std::string SampleProfile,
1485     std::string ProfileRemapping, BackendAction Action) {
1486   StringMap<DenseMap<GlobalValue::GUID, GlobalValueSummary *>>
1487       ModuleToDefinedGVSummaries;
1488   CombinedIndex->collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries);
1489 
1490   setCommandLineOpts(CGOpts);
1491 
1492   // We can simply import the values mentioned in the combined index, since
1493   // we should only invoke this using the individual indexes written out
1494   // via a WriteIndexesThinBackend.
1495   FunctionImporter::ImportMapTy ImportList;
1496   std::vector<std::unique_ptr<llvm::MemoryBuffer>> OwnedImports;
1497   MapVector<llvm::StringRef, llvm::BitcodeModule> ModuleMap;
1498   if (!lto::loadReferencedModules(*M, *CombinedIndex, ImportList, ModuleMap,
1499                                   OwnedImports))
1500     return;
1501 
1502   auto AddStream = [&](size_t Task) {
1503     return std::make_unique<lto::NativeObjectStream>(std::move(OS));
1504   };
1505   lto::Config Conf;
1506   if (CGOpts.SaveTempsFilePrefix != "") {
1507     if (Error E = Conf.addSaveTemps(CGOpts.SaveTempsFilePrefix + ".",
1508                                     /* UseInputModulePath */ false)) {
1509       handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1510         errs() << "Error setting up ThinLTO save-temps: " << EIB.message()
1511                << '\n';
1512       });
1513     }
1514   }
1515   Conf.CPU = TOpts.CPU;
1516   Conf.CodeModel = getCodeModel(CGOpts);
1517   Conf.MAttrs = TOpts.Features;
1518   Conf.RelocModel = CGOpts.RelocationModel;
1519   Conf.CGOptLevel = getCGOptLevel(CGOpts);
1520   Conf.OptLevel = CGOpts.OptimizationLevel;
1521   initTargetOptions(Diags, Conf.Options, CGOpts, TOpts, LOpts, HeaderOpts);
1522   Conf.SampleProfile = std::move(SampleProfile);
1523   Conf.PTO.LoopUnrolling = CGOpts.UnrollLoops;
1524   // For historical reasons, loop interleaving is set to mirror setting for loop
1525   // unrolling.
1526   Conf.PTO.LoopInterleaving = CGOpts.UnrollLoops;
1527   Conf.PTO.LoopVectorization = CGOpts.VectorizeLoop;
1528   Conf.PTO.SLPVectorization = CGOpts.VectorizeSLP;
1529   // Only enable CGProfilePass when using integrated assembler, since
1530   // non-integrated assemblers don't recognize .cgprofile section.
1531   Conf.PTO.CallGraphProfile = !CGOpts.DisableIntegratedAS;
1532 
1533   // Context sensitive profile.
1534   if (CGOpts.hasProfileCSIRInstr()) {
1535     Conf.RunCSIRInstr = true;
1536     Conf.CSIRProfile = std::move(CGOpts.InstrProfileOutput);
1537   } else if (CGOpts.hasProfileCSIRUse()) {
1538     Conf.RunCSIRInstr = false;
1539     Conf.CSIRProfile = std::move(CGOpts.ProfileInstrumentUsePath);
1540   }
1541 
1542   Conf.ProfileRemapping = std::move(ProfileRemapping);
1543   Conf.UseNewPM = !CGOpts.LegacyPassManager;
1544   Conf.DebugPassManager = CGOpts.DebugPassManager;
1545   Conf.RemarksWithHotness = CGOpts.DiagnosticsWithHotness;
1546   Conf.RemarksFilename = CGOpts.OptRecordFile;
1547   Conf.RemarksPasses = CGOpts.OptRecordPasses;
1548   Conf.RemarksFormat = CGOpts.OptRecordFormat;
1549   Conf.SplitDwarfFile = CGOpts.SplitDwarfFile;
1550   Conf.SplitDwarfOutput = CGOpts.SplitDwarfOutput;
1551   switch (Action) {
1552   case Backend_EmitNothing:
1553     Conf.PreCodeGenModuleHook = [](size_t Task, const Module &Mod) {
1554       return false;
1555     };
1556     break;
1557   case Backend_EmitLL:
1558     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1559       M->print(*OS, nullptr, CGOpts.EmitLLVMUseLists);
1560       return false;
1561     };
1562     break;
1563   case Backend_EmitBC:
1564     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1565       WriteBitcodeToFile(*M, *OS, CGOpts.EmitLLVMUseLists);
1566       return false;
1567     };
1568     break;
1569   default:
1570     Conf.CGFileType = getCodeGenFileType(Action);
1571     break;
1572   }
1573   if (Error E =
1574           thinBackend(Conf, -1, AddStream, *M, *CombinedIndex, ImportList,
1575                       ModuleToDefinedGVSummaries[M->getModuleIdentifier()],
1576                       ModuleMap, CGOpts.CmdArgs)) {
1577     handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1578       errs() << "Error running ThinLTO backend: " << EIB.message() << '\n';
1579     });
1580   }
1581 }
1582 
1583 void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
1584                               const HeaderSearchOptions &HeaderOpts,
1585                               const CodeGenOptions &CGOpts,
1586                               const clang::TargetOptions &TOpts,
1587                               const LangOptions &LOpts,
1588                               const llvm::DataLayout &TDesc, Module *M,
1589                               BackendAction Action,
1590                               std::unique_ptr<raw_pwrite_stream> OS) {
1591 
1592   llvm::TimeTraceScope TimeScope("Backend");
1593 
1594   std::unique_ptr<llvm::Module> EmptyModule;
1595   if (!CGOpts.ThinLTOIndexFile.empty()) {
1596     // If we are performing a ThinLTO importing compile, load the function index
1597     // into memory and pass it into runThinLTOBackend, which will run the
1598     // function importer and invoke LTO passes.
1599     Expected<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
1600         llvm::getModuleSummaryIndexForFile(CGOpts.ThinLTOIndexFile,
1601                                            /*IgnoreEmptyThinLTOIndexFile*/true);
1602     if (!IndexOrErr) {
1603       logAllUnhandledErrors(IndexOrErr.takeError(), errs(),
1604                             "Error loading index file '" +
1605                             CGOpts.ThinLTOIndexFile + "': ");
1606       return;
1607     }
1608     std::unique_ptr<ModuleSummaryIndex> CombinedIndex = std::move(*IndexOrErr);
1609     // A null CombinedIndex means we should skip ThinLTO compilation
1610     // (LLVM will optionally ignore empty index files, returning null instead
1611     // of an error).
1612     if (CombinedIndex) {
1613       if (!CombinedIndex->skipModuleByDistributedBackend()) {
1614         runThinLTOBackend(Diags, CombinedIndex.get(), M, HeaderOpts, CGOpts,
1615                           TOpts, LOpts, std::move(OS), CGOpts.SampleProfileFile,
1616                           CGOpts.ProfileRemappingFile, Action);
1617         return;
1618       }
1619       // Distributed indexing detected that nothing from the module is needed
1620       // for the final linking. So we can skip the compilation. We sill need to
1621       // output an empty object file to make sure that a linker does not fail
1622       // trying to read it. Also for some features, like CFI, we must skip
1623       // the compilation as CombinedIndex does not contain all required
1624       // information.
1625       EmptyModule = std::make_unique<llvm::Module>("empty", M->getContext());
1626       EmptyModule->setTargetTriple(M->getTargetTriple());
1627       M = EmptyModule.get();
1628     }
1629   }
1630 
1631   EmitAssemblyHelper AsmHelper(Diags, HeaderOpts, CGOpts, TOpts, LOpts, M);
1632 
1633   if (!CGOpts.LegacyPassManager)
1634     AsmHelper.EmitAssemblyWithNewPassManager(Action, std::move(OS));
1635   else
1636     AsmHelper.EmitAssembly(Action, std::move(OS));
1637 
1638   // Verify clang's TargetInfo DataLayout against the LLVM TargetMachine's
1639   // DataLayout.
1640   if (AsmHelper.TM) {
1641     std::string DLDesc = M->getDataLayout().getStringRepresentation();
1642     if (DLDesc != TDesc.getStringRepresentation()) {
1643       unsigned DiagID = Diags.getCustomDiagID(
1644           DiagnosticsEngine::Error, "backend data layout '%0' does not match "
1645                                     "expected target description '%1'");
1646       Diags.Report(DiagID) << DLDesc << TDesc.getStringRepresentation();
1647     }
1648   }
1649 }
1650 
1651 // With -fembed-bitcode, save a copy of the llvm IR as data in the
1652 // __LLVM,__bitcode section.
1653 void clang::EmbedBitcode(llvm::Module *M, const CodeGenOptions &CGOpts,
1654                          llvm::MemoryBufferRef Buf) {
1655   if (CGOpts.getEmbedBitcode() == CodeGenOptions::Embed_Off)
1656     return;
1657   llvm::EmbedBitcodeInModule(
1658       *M, Buf, CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Marker,
1659       CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Bitcode,
1660       CGOpts.CmdArgs);
1661 }
1662