xref: /freebsd/contrib/llvm-project/clang/lib/CodeGen/BackendUtil.cpp (revision 77013d11e6483b970af25e13c9b892075742f7e5) 
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/GVN.h"
80 #include "llvm/Transforms/Scalar/LowerMatrixIntrinsics.h"
81 #include "llvm/Transforms/Utils.h"
82 #include "llvm/Transforms/Utils/CanonicalizeAliases.h"
83 #include "llvm/Transforms/Utils/EntryExitInstrumenter.h"
84 #include "llvm/Transforms/Utils/NameAnonGlobals.h"
85 #include "llvm/Transforms/Utils/SymbolRewriter.h"
86 #include "llvm/Transforms/Utils/UniqueInternalLinkageNames.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   PM.add(createAddressSanitizerFunctionPass(/*CompileKernel*/ false, Recover,
290                                             UseAfterScope));
291   PM.add(createModuleAddressSanitizerLegacyPassPass(
292       /*CompileKernel*/ false, Recover, UseGlobalsGC, UseOdrIndicator));
293 }
294 
295 static void addKernelAddressSanitizerPasses(const PassManagerBuilder &Builder,
296                                             legacy::PassManagerBase &PM) {
297   PM.add(createAddressSanitizerFunctionPass(
298       /*CompileKernel*/ true, /*Recover*/ true, /*UseAfterScope*/ false));
299   PM.add(createModuleAddressSanitizerLegacyPassPass(
300       /*CompileKernel*/ true, /*Recover*/ true, /*UseGlobalsGC*/ true,
301       /*UseOdrIndicator*/ false));
302 }
303 
304 static void addHWAddressSanitizerPasses(const PassManagerBuilder &Builder,
305                                             legacy::PassManagerBase &PM) {
306   const PassManagerBuilderWrapper &BuilderWrapper =
307       static_cast<const PassManagerBuilderWrapper &>(Builder);
308   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
309   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::HWAddress);
310   PM.add(
311       createHWAddressSanitizerLegacyPassPass(/*CompileKernel*/ false, Recover));
312 }
313 
314 static void addKernelHWAddressSanitizerPasses(const PassManagerBuilder &Builder,
315                                             legacy::PassManagerBase &PM) {
316   PM.add(createHWAddressSanitizerLegacyPassPass(
317       /*CompileKernel*/ true, /*Recover*/ true));
318 }
319 
320 static void addGeneralOptsForMemorySanitizer(const PassManagerBuilder &Builder,
321                                              legacy::PassManagerBase &PM,
322                                              bool CompileKernel) {
323   const PassManagerBuilderWrapper &BuilderWrapper =
324       static_cast<const PassManagerBuilderWrapper&>(Builder);
325   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
326   int TrackOrigins = CGOpts.SanitizeMemoryTrackOrigins;
327   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Memory);
328   PM.add(createMemorySanitizerLegacyPassPass(
329       MemorySanitizerOptions{TrackOrigins, Recover, CompileKernel}));
330 
331   // MemorySanitizer inserts complex instrumentation that mostly follows
332   // the logic of the original code, but operates on "shadow" values.
333   // It can benefit from re-running some general purpose optimization passes.
334   if (Builder.OptLevel > 0) {
335     PM.add(createEarlyCSEPass());
336     PM.add(createReassociatePass());
337     PM.add(createLICMPass());
338     PM.add(createGVNPass());
339     PM.add(createInstructionCombiningPass());
340     PM.add(createDeadStoreEliminationPass());
341   }
342 }
343 
344 static void addMemorySanitizerPass(const PassManagerBuilder &Builder,
345                                    legacy::PassManagerBase &PM) {
346   addGeneralOptsForMemorySanitizer(Builder, PM, /*CompileKernel*/ false);
347 }
348 
349 static void addKernelMemorySanitizerPass(const PassManagerBuilder &Builder,
350                                          legacy::PassManagerBase &PM) {
351   addGeneralOptsForMemorySanitizer(Builder, PM, /*CompileKernel*/ true);
352 }
353 
354 static void addThreadSanitizerPass(const PassManagerBuilder &Builder,
355                                    legacy::PassManagerBase &PM) {
356   PM.add(createThreadSanitizerLegacyPassPass());
357 }
358 
359 static void addDataFlowSanitizerPass(const PassManagerBuilder &Builder,
360                                      legacy::PassManagerBase &PM) {
361   const PassManagerBuilderWrapper &BuilderWrapper =
362       static_cast<const PassManagerBuilderWrapper&>(Builder);
363   const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
364   PM.add(
365       createDataFlowSanitizerLegacyPassPass(LangOpts.SanitizerBlacklistFiles));
366 }
367 
368 static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
369                                          const CodeGenOptions &CodeGenOpts) {
370   TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple);
371 
372   switch (CodeGenOpts.getVecLib()) {
373   case CodeGenOptions::Accelerate:
374     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::Accelerate);
375     break;
376   case CodeGenOptions::LIBMVEC:
377     switch(TargetTriple.getArch()) {
378       default:
379         break;
380       case llvm::Triple::x86_64:
381         TLII->addVectorizableFunctionsFromVecLib
382                 (TargetLibraryInfoImpl::LIBMVEC_X86);
383         break;
384     }
385     break;
386   case CodeGenOptions::MASSV:
387     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::MASSV);
388     break;
389   case CodeGenOptions::SVML:
390     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::SVML);
391     break;
392   default:
393     break;
394   }
395   return TLII;
396 }
397 
398 static void addSymbolRewriterPass(const CodeGenOptions &Opts,
399                                   legacy::PassManager *MPM) {
400   llvm::SymbolRewriter::RewriteDescriptorList DL;
401 
402   llvm::SymbolRewriter::RewriteMapParser MapParser;
403   for (const auto &MapFile : Opts.RewriteMapFiles)
404     MapParser.parse(MapFile, &DL);
405 
406   MPM->add(createRewriteSymbolsPass(DL));
407 }
408 
409 static CodeGenOpt::Level getCGOptLevel(const CodeGenOptions &CodeGenOpts) {
410   switch (CodeGenOpts.OptimizationLevel) {
411   default:
412     llvm_unreachable("Invalid optimization level!");
413   case 0:
414     return CodeGenOpt::None;
415   case 1:
416     return CodeGenOpt::Less;
417   case 2:
418     return CodeGenOpt::Default; // O2/Os/Oz
419   case 3:
420     return CodeGenOpt::Aggressive;
421   }
422 }
423 
424 static Optional<llvm::CodeModel::Model>
425 getCodeModel(const CodeGenOptions &CodeGenOpts) {
426   unsigned CodeModel = llvm::StringSwitch<unsigned>(CodeGenOpts.CodeModel)
427                            .Case("tiny", llvm::CodeModel::Tiny)
428                            .Case("small", llvm::CodeModel::Small)
429                            .Case("kernel", llvm::CodeModel::Kernel)
430                            .Case("medium", llvm::CodeModel::Medium)
431                            .Case("large", llvm::CodeModel::Large)
432                            .Case("default", ~1u)
433                            .Default(~0u);
434   assert(CodeModel != ~0u && "invalid code model!");
435   if (CodeModel == ~1u)
436     return None;
437   return static_cast<llvm::CodeModel::Model>(CodeModel);
438 }
439 
440 static CodeGenFileType getCodeGenFileType(BackendAction Action) {
441   if (Action == Backend_EmitObj)
442     return CGFT_ObjectFile;
443   else if (Action == Backend_EmitMCNull)
444     return CGFT_Null;
445   else {
446     assert(Action == Backend_EmitAssembly && "Invalid action!");
447     return CGFT_AssemblyFile;
448   }
449 }
450 
451 static bool initTargetOptions(DiagnosticsEngine &Diags,
452                               llvm::TargetOptions &Options,
453                               const CodeGenOptions &CodeGenOpts,
454                               const clang::TargetOptions &TargetOpts,
455                               const LangOptions &LangOpts,
456                               const HeaderSearchOptions &HSOpts) {
457   switch (LangOpts.getThreadModel()) {
458   case LangOptions::ThreadModelKind::POSIX:
459     Options.ThreadModel = llvm::ThreadModel::POSIX;
460     break;
461   case LangOptions::ThreadModelKind::Single:
462     Options.ThreadModel = llvm::ThreadModel::Single;
463     break;
464   }
465 
466   // Set float ABI type.
467   assert((CodeGenOpts.FloatABI == "soft" || CodeGenOpts.FloatABI == "softfp" ||
468           CodeGenOpts.FloatABI == "hard" || CodeGenOpts.FloatABI.empty()) &&
469          "Invalid Floating Point ABI!");
470   Options.FloatABIType =
471       llvm::StringSwitch<llvm::FloatABI::ABIType>(CodeGenOpts.FloatABI)
472           .Case("soft", llvm::FloatABI::Soft)
473           .Case("softfp", llvm::FloatABI::Soft)
474           .Case("hard", llvm::FloatABI::Hard)
475           .Default(llvm::FloatABI::Default);
476 
477   // Set FP fusion mode.
478   switch (LangOpts.getDefaultFPContractMode()) {
479   case LangOptions::FPM_Off:
480     // Preserve any contraction performed by the front-end.  (Strict performs
481     // splitting of the muladd intrinsic in the backend.)
482     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
483     break;
484   case LangOptions::FPM_On:
485   case LangOptions::FPM_FastHonorPragmas:
486     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
487     break;
488   case LangOptions::FPM_Fast:
489     Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
490     break;
491   }
492 
493   Options.BinutilsVersion =
494       llvm::TargetMachine::parseBinutilsVersion(CodeGenOpts.BinutilsVersion);
495   Options.UseInitArray = CodeGenOpts.UseInitArray;
496   Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
497   Options.CompressDebugSections = CodeGenOpts.getCompressDebugSections();
498   Options.RelaxELFRelocations = CodeGenOpts.RelaxELFRelocations;
499 
500   // Set EABI version.
501   Options.EABIVersion = TargetOpts.EABIVersion;
502 
503   if (LangOpts.hasSjLjExceptions())
504     Options.ExceptionModel = llvm::ExceptionHandling::SjLj;
505   if (LangOpts.hasSEHExceptions())
506     Options.ExceptionModel = llvm::ExceptionHandling::WinEH;
507   if (LangOpts.hasDWARFExceptions())
508     Options.ExceptionModel = llvm::ExceptionHandling::DwarfCFI;
509   if (LangOpts.hasWasmExceptions())
510     Options.ExceptionModel = llvm::ExceptionHandling::Wasm;
511 
512   Options.NoInfsFPMath = LangOpts.NoHonorInfs;
513   Options.NoNaNsFPMath = LangOpts.NoHonorNaNs;
514   Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
515   Options.UnsafeFPMath = LangOpts.UnsafeFPMath;
516   Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
517 
518   Options.BBSections =
519       llvm::StringSwitch<llvm::BasicBlockSection>(CodeGenOpts.BBSections)
520           .Case("all", llvm::BasicBlockSection::All)
521           .Case("labels", llvm::BasicBlockSection::Labels)
522           .StartsWith("list=", llvm::BasicBlockSection::List)
523           .Case("none", llvm::BasicBlockSection::None)
524           .Default(llvm::BasicBlockSection::None);
525 
526   if (Options.BBSections == llvm::BasicBlockSection::List) {
527     ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
528         MemoryBuffer::getFile(CodeGenOpts.BBSections.substr(5));
529     if (!MBOrErr) {
530       Diags.Report(diag::err_fe_unable_to_load_basic_block_sections_file)
531           << MBOrErr.getError().message();
532       return false;
533     }
534     Options.BBSectionsFuncListBuf = std::move(*MBOrErr);
535   }
536 
537   Options.EnableMachineFunctionSplitter = CodeGenOpts.SplitMachineFunctions;
538   Options.FunctionSections = CodeGenOpts.FunctionSections;
539   Options.DataSections = CodeGenOpts.DataSections;
540   Options.IgnoreXCOFFVisibility = CodeGenOpts.IgnoreXCOFFVisibility;
541   Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
542   Options.UniqueBasicBlockSectionNames =
543       CodeGenOpts.UniqueBasicBlockSectionNames;
544   Options.StackProtectorGuard =
545       llvm::StringSwitch<llvm::StackProtectorGuards>(CodeGenOpts
546           .StackProtectorGuard)
547           .Case("tls", llvm::StackProtectorGuards::TLS)
548           .Case("global", llvm::StackProtectorGuards::Global)
549           .Default(llvm::StackProtectorGuards::None);
550   Options.StackProtectorGuardOffset = CodeGenOpts.StackProtectorGuardOffset;
551   Options.StackProtectorGuardReg = CodeGenOpts.StackProtectorGuardReg;
552   Options.TLSSize = CodeGenOpts.TLSSize;
553   Options.EmulatedTLS = CodeGenOpts.EmulatedTLS;
554   Options.ExplicitEmulatedTLS = CodeGenOpts.ExplicitEmulatedTLS;
555   Options.DebuggerTuning = CodeGenOpts.getDebuggerTuning();
556   Options.EmitStackSizeSection = CodeGenOpts.StackSizeSection;
557   Options.EmitAddrsig = CodeGenOpts.Addrsig;
558   Options.ForceDwarfFrameSection = CodeGenOpts.ForceDwarfFrameSection;
559   Options.EmitCallSiteInfo = CodeGenOpts.EmitCallSiteInfo;
560   Options.EnableAIXExtendedAltivecABI = CodeGenOpts.EnableAIXExtendedAltivecABI;
561   Options.PseudoProbeForProfiling = CodeGenOpts.PseudoProbeForProfiling;
562   Options.ValueTrackingVariableLocations =
563       CodeGenOpts.ValueTrackingVariableLocations;
564   Options.XRayOmitFunctionIndex = CodeGenOpts.XRayOmitFunctionIndex;
565 
566   Options.MCOptions.SplitDwarfFile = CodeGenOpts.SplitDwarfFile;
567   Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
568   Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
569   Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
570   Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
571   Options.MCOptions.MCIncrementalLinkerCompatible =
572       CodeGenOpts.IncrementalLinkerCompatible;
573   Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
574   Options.MCOptions.MCNoWarn = CodeGenOpts.NoWarn;
575   Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
576   Options.MCOptions.Dwarf64 = CodeGenOpts.Dwarf64;
577   Options.MCOptions.PreserveAsmComments = CodeGenOpts.PreserveAsmComments;
578   Options.MCOptions.ABIName = TargetOpts.ABI;
579   for (const auto &Entry : HSOpts.UserEntries)
580     if (!Entry.IsFramework &&
581         (Entry.Group == frontend::IncludeDirGroup::Quoted ||
582          Entry.Group == frontend::IncludeDirGroup::Angled ||
583          Entry.Group == frontend::IncludeDirGroup::System))
584       Options.MCOptions.IASSearchPaths.push_back(
585           Entry.IgnoreSysRoot ? Entry.Path : HSOpts.Sysroot + Entry.Path);
586   Options.MCOptions.Argv0 = CodeGenOpts.Argv0;
587   Options.MCOptions.CommandLineArgs = CodeGenOpts.CommandLineArgs;
588 
589   return true;
590 }
591 
592 static Optional<GCOVOptions> getGCOVOptions(const CodeGenOptions &CodeGenOpts,
593                                             const LangOptions &LangOpts) {
594   if (!CodeGenOpts.EmitGcovArcs && !CodeGenOpts.EmitGcovNotes)
595     return None;
596   // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
597   // LLVM's -default-gcov-version flag is set to something invalid.
598   GCOVOptions Options;
599   Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
600   Options.EmitData = CodeGenOpts.EmitGcovArcs;
601   llvm::copy(CodeGenOpts.CoverageVersion, std::begin(Options.Version));
602   Options.NoRedZone = CodeGenOpts.DisableRedZone;
603   Options.Filter = CodeGenOpts.ProfileFilterFiles;
604   Options.Exclude = CodeGenOpts.ProfileExcludeFiles;
605   Options.Atomic = CodeGenOpts.AtomicProfileUpdate;
606   return Options;
607 }
608 
609 static Optional<InstrProfOptions>
610 getInstrProfOptions(const CodeGenOptions &CodeGenOpts,
611                     const LangOptions &LangOpts) {
612   if (!CodeGenOpts.hasProfileClangInstr())
613     return None;
614   InstrProfOptions Options;
615   Options.NoRedZone = CodeGenOpts.DisableRedZone;
616   Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
617   Options.Atomic = CodeGenOpts.AtomicProfileUpdate;
618   return Options;
619 }
620 
621 void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
622                                       legacy::FunctionPassManager &FPM) {
623   // Handle disabling of all LLVM passes, where we want to preserve the
624   // internal module before any optimization.
625   if (CodeGenOpts.DisableLLVMPasses)
626     return;
627 
628   // Figure out TargetLibraryInfo.  This needs to be added to MPM and FPM
629   // manually (and not via PMBuilder), since some passes (eg. InstrProfiling)
630   // are inserted before PMBuilder ones - they'd get the default-constructed
631   // TLI with an unknown target otherwise.
632   Triple TargetTriple(TheModule->getTargetTriple());
633   std::unique_ptr<TargetLibraryInfoImpl> TLII(
634       createTLII(TargetTriple, CodeGenOpts));
635 
636   // If we reached here with a non-empty index file name, then the index file
637   // was empty and we are not performing ThinLTO backend compilation (used in
638   // testing in a distributed build environment). Drop any the type test
639   // assume sequences inserted for whole program vtables so that codegen doesn't
640   // complain.
641   if (!CodeGenOpts.ThinLTOIndexFile.empty())
642     MPM.add(createLowerTypeTestsPass(/*ExportSummary=*/nullptr,
643                                      /*ImportSummary=*/nullptr,
644                                      /*DropTypeTests=*/true));
645 
646   PassManagerBuilderWrapper PMBuilder(TargetTriple, CodeGenOpts, LangOpts);
647 
648   // At O0 and O1 we only run the always inliner which is more efficient. At
649   // higher optimization levels we run the normal inliner.
650   if (CodeGenOpts.OptimizationLevel <= 1) {
651     bool InsertLifetimeIntrinsics = ((CodeGenOpts.OptimizationLevel != 0 &&
652                                       !CodeGenOpts.DisableLifetimeMarkers) ||
653                                      LangOpts.Coroutines);
654     PMBuilder.Inliner = createAlwaysInlinerLegacyPass(InsertLifetimeIntrinsics);
655   } else {
656     // We do not want to inline hot callsites for SamplePGO module-summary build
657     // because profile annotation will happen again in ThinLTO backend, and we
658     // want the IR of the hot path to match the profile.
659     PMBuilder.Inliner = createFunctionInliningPass(
660         CodeGenOpts.OptimizationLevel, CodeGenOpts.OptimizeSize,
661         (!CodeGenOpts.SampleProfileFile.empty() &&
662          CodeGenOpts.PrepareForThinLTO));
663   }
664 
665   PMBuilder.OptLevel = CodeGenOpts.OptimizationLevel;
666   PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
667   PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
668   PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
669   // Only enable CGProfilePass when using integrated assembler, since
670   // non-integrated assemblers don't recognize .cgprofile section.
671   PMBuilder.CallGraphProfile = !CodeGenOpts.DisableIntegratedAS;
672 
673   PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
674   // Loop interleaving in the loop vectorizer has historically been set to be
675   // enabled when loop unrolling is enabled.
676   PMBuilder.LoopsInterleaved = CodeGenOpts.UnrollLoops;
677   PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
678   PMBuilder.PrepareForThinLTO = CodeGenOpts.PrepareForThinLTO;
679   PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
680   PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
681 
682   MPM.add(new TargetLibraryInfoWrapperPass(*TLII));
683 
684   if (TM)
685     TM->adjustPassManager(PMBuilder);
686 
687   if (CodeGenOpts.DebugInfoForProfiling ||
688       !CodeGenOpts.SampleProfileFile.empty())
689     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
690                            addAddDiscriminatorsPass);
691 
692   // In ObjC ARC mode, add the main ARC optimization passes.
693   if (LangOpts.ObjCAutoRefCount) {
694     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
695                            addObjCARCExpandPass);
696     PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
697                            addObjCARCAPElimPass);
698     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
699                            addObjCARCOptPass);
700   }
701 
702   if (LangOpts.Coroutines)
703     addCoroutinePassesToExtensionPoints(PMBuilder);
704 
705   if (!CodeGenOpts.MemoryProfileOutput.empty()) {
706     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
707                            addMemProfilerPasses);
708     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
709                            addMemProfilerPasses);
710   }
711 
712   if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds)) {
713     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
714                            addBoundsCheckingPass);
715     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
716                            addBoundsCheckingPass);
717   }
718 
719   if (CodeGenOpts.SanitizeCoverageType ||
720       CodeGenOpts.SanitizeCoverageIndirectCalls ||
721       CodeGenOpts.SanitizeCoverageTraceCmp) {
722     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
723                            addSanitizerCoveragePass);
724     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
725                            addSanitizerCoveragePass);
726   }
727 
728   if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
729     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
730                            addAddressSanitizerPasses);
731     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
732                            addAddressSanitizerPasses);
733   }
734 
735   if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
736     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
737                            addKernelAddressSanitizerPasses);
738     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
739                            addKernelAddressSanitizerPasses);
740   }
741 
742   if (LangOpts.Sanitize.has(SanitizerKind::HWAddress)) {
743     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
744                            addHWAddressSanitizerPasses);
745     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
746                            addHWAddressSanitizerPasses);
747   }
748 
749   if (LangOpts.Sanitize.has(SanitizerKind::KernelHWAddress)) {
750     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
751                            addKernelHWAddressSanitizerPasses);
752     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
753                            addKernelHWAddressSanitizerPasses);
754   }
755 
756   if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
757     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
758                            addMemorySanitizerPass);
759     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
760                            addMemorySanitizerPass);
761   }
762 
763   if (LangOpts.Sanitize.has(SanitizerKind::KernelMemory)) {
764     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
765                            addKernelMemorySanitizerPass);
766     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
767                            addKernelMemorySanitizerPass);
768   }
769 
770   if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
771     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
772                            addThreadSanitizerPass);
773     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
774                            addThreadSanitizerPass);
775   }
776 
777   if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
778     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
779                            addDataFlowSanitizerPass);
780     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
781                            addDataFlowSanitizerPass);
782   }
783 
784   // Set up the per-function pass manager.
785   FPM.add(new TargetLibraryInfoWrapperPass(*TLII));
786   if (CodeGenOpts.VerifyModule)
787     FPM.add(createVerifierPass());
788 
789   // Set up the per-module pass manager.
790   if (!CodeGenOpts.RewriteMapFiles.empty())
791     addSymbolRewriterPass(CodeGenOpts, &MPM);
792 
793   // Add UniqueInternalLinkageNames Pass which renames internal linkage symbols
794   // with unique names.
795   if (CodeGenOpts.UniqueInternalLinkageNames) {
796     MPM.add(createUniqueInternalLinkageNamesPass());
797   }
798 
799   if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts, LangOpts)) {
800     MPM.add(createGCOVProfilerPass(*Options));
801     if (CodeGenOpts.getDebugInfo() == codegenoptions::NoDebugInfo)
802       MPM.add(createStripSymbolsPass(true));
803   }
804 
805   if (Optional<InstrProfOptions> Options =
806           getInstrProfOptions(CodeGenOpts, LangOpts))
807     MPM.add(createInstrProfilingLegacyPass(*Options, false));
808 
809   bool hasIRInstr = false;
810   if (CodeGenOpts.hasProfileIRInstr()) {
811     PMBuilder.EnablePGOInstrGen = true;
812     hasIRInstr = true;
813   }
814   if (CodeGenOpts.hasProfileCSIRInstr()) {
815     assert(!CodeGenOpts.hasProfileCSIRUse() &&
816            "Cannot have both CSProfileUse pass and CSProfileGen pass at the "
817            "same time");
818     assert(!hasIRInstr &&
819            "Cannot have both ProfileGen pass and CSProfileGen pass at the "
820            "same time");
821     PMBuilder.EnablePGOCSInstrGen = true;
822     hasIRInstr = true;
823   }
824   if (hasIRInstr) {
825     if (!CodeGenOpts.InstrProfileOutput.empty())
826       PMBuilder.PGOInstrGen = CodeGenOpts.InstrProfileOutput;
827     else
828       PMBuilder.PGOInstrGen = std::string(DefaultProfileGenName);
829   }
830   if (CodeGenOpts.hasProfileIRUse()) {
831     PMBuilder.PGOInstrUse = CodeGenOpts.ProfileInstrumentUsePath;
832     PMBuilder.EnablePGOCSInstrUse = CodeGenOpts.hasProfileCSIRUse();
833   }
834 
835   if (!CodeGenOpts.SampleProfileFile.empty())
836     PMBuilder.PGOSampleUse = CodeGenOpts.SampleProfileFile;
837 
838   PMBuilder.populateFunctionPassManager(FPM);
839   PMBuilder.populateModulePassManager(MPM);
840 }
841 
842 static void setCommandLineOpts(const CodeGenOptions &CodeGenOpts) {
843   SmallVector<const char *, 16> BackendArgs;
844   BackendArgs.push_back("clang"); // Fake program name.
845   if (!CodeGenOpts.DebugPass.empty()) {
846     BackendArgs.push_back("-debug-pass");
847     BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
848   }
849   if (!CodeGenOpts.LimitFloatPrecision.empty()) {
850     BackendArgs.push_back("-limit-float-precision");
851     BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
852   }
853   BackendArgs.push_back(nullptr);
854   llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
855                                     BackendArgs.data());
856 }
857 
858 void EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
859   // Create the TargetMachine for generating code.
860   std::string Error;
861   std::string Triple = TheModule->getTargetTriple();
862   const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
863   if (!TheTarget) {
864     if (MustCreateTM)
865       Diags.Report(diag::err_fe_unable_to_create_target) << Error;
866     return;
867   }
868 
869   Optional<llvm::CodeModel::Model> CM = getCodeModel(CodeGenOpts);
870   std::string FeaturesStr =
871       llvm::join(TargetOpts.Features.begin(), TargetOpts.Features.end(), ",");
872   llvm::Reloc::Model RM = CodeGenOpts.RelocationModel;
873   CodeGenOpt::Level OptLevel = getCGOptLevel(CodeGenOpts);
874 
875   llvm::TargetOptions Options;
876   if (!initTargetOptions(Diags, Options, CodeGenOpts, TargetOpts, LangOpts,
877                          HSOpts))
878     return;
879   TM.reset(TheTarget->createTargetMachine(Triple, TargetOpts.CPU, FeaturesStr,
880                                           Options, RM, CM, OptLevel));
881 }
882 
883 bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
884                                        BackendAction Action,
885                                        raw_pwrite_stream &OS,
886                                        raw_pwrite_stream *DwoOS) {
887   // Add LibraryInfo.
888   llvm::Triple TargetTriple(TheModule->getTargetTriple());
889   std::unique_ptr<TargetLibraryInfoImpl> TLII(
890       createTLII(TargetTriple, CodeGenOpts));
891   CodeGenPasses.add(new TargetLibraryInfoWrapperPass(*TLII));
892 
893   // Normal mode, emit a .s or .o file by running the code generator. Note,
894   // this also adds codegenerator level optimization passes.
895   CodeGenFileType CGFT = getCodeGenFileType(Action);
896 
897   // Add ObjC ARC final-cleanup optimizations. This is done as part of the
898   // "codegen" passes so that it isn't run multiple times when there is
899   // inlining happening.
900   if (CodeGenOpts.OptimizationLevel > 0)
901     CodeGenPasses.add(createObjCARCContractPass());
902 
903   if (TM->addPassesToEmitFile(CodeGenPasses, OS, DwoOS, CGFT,
904                               /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
905     Diags.Report(diag::err_fe_unable_to_interface_with_target);
906     return false;
907   }
908 
909   return true;
910 }
911 
912 void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
913                                       std::unique_ptr<raw_pwrite_stream> OS) {
914   TimeRegion Region(CodeGenOpts.TimePasses ? &CodeGenerationTime : nullptr);
915 
916   setCommandLineOpts(CodeGenOpts);
917 
918   bool UsesCodeGen = (Action != Backend_EmitNothing &&
919                       Action != Backend_EmitBC &&
920                       Action != Backend_EmitLL);
921   CreateTargetMachine(UsesCodeGen);
922 
923   if (UsesCodeGen && !TM)
924     return;
925   if (TM)
926     TheModule->setDataLayout(TM->createDataLayout());
927 
928   legacy::PassManager PerModulePasses;
929   PerModulePasses.add(
930       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
931 
932   legacy::FunctionPassManager PerFunctionPasses(TheModule);
933   PerFunctionPasses.add(
934       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
935 
936   CreatePasses(PerModulePasses, PerFunctionPasses);
937 
938   legacy::PassManager CodeGenPasses;
939   CodeGenPasses.add(
940       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
941 
942   std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
943 
944   switch (Action) {
945   case Backend_EmitNothing:
946     break;
947 
948   case Backend_EmitBC:
949     if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
950       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
951         ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
952         if (!ThinLinkOS)
953           return;
954       }
955       TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
956                                CodeGenOpts.EnableSplitLTOUnit);
957       PerModulePasses.add(createWriteThinLTOBitcodePass(
958           *OS, ThinLinkOS ? &ThinLinkOS->os() : nullptr));
959     } else {
960       // Emit a module summary by default for Regular LTO except for ld64
961       // targets
962       bool EmitLTOSummary =
963           (CodeGenOpts.PrepareForLTO &&
964            !CodeGenOpts.DisableLLVMPasses &&
965            llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
966                llvm::Triple::Apple);
967       if (EmitLTOSummary) {
968         if (!TheModule->getModuleFlag("ThinLTO"))
969           TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
970         TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
971                                  uint32_t(1));
972       }
973 
974       PerModulePasses.add(createBitcodeWriterPass(
975           *OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
976     }
977     break;
978 
979   case Backend_EmitLL:
980     PerModulePasses.add(
981         createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
982     break;
983 
984   default:
985     if (!CodeGenOpts.SplitDwarfOutput.empty()) {
986       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
987       if (!DwoOS)
988         return;
989     }
990     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
991                        DwoOS ? &DwoOS->os() : nullptr))
992       return;
993   }
994 
995   // Before executing passes, print the final values of the LLVM options.
996   cl::PrintOptionValues();
997 
998   // Run passes. For now we do all passes at once, but eventually we
999   // would like to have the option of streaming code generation.
1000 
1001   {
1002     PrettyStackTraceString CrashInfo("Per-function optimization");
1003     llvm::TimeTraceScope TimeScope("PerFunctionPasses");
1004 
1005     PerFunctionPasses.doInitialization();
1006     for (Function &F : *TheModule)
1007       if (!F.isDeclaration())
1008         PerFunctionPasses.run(F);
1009     PerFunctionPasses.doFinalization();
1010   }
1011 
1012   {
1013     PrettyStackTraceString CrashInfo("Per-module optimization passes");
1014     llvm::TimeTraceScope TimeScope("PerModulePasses");
1015     PerModulePasses.run(*TheModule);
1016   }
1017 
1018   {
1019     PrettyStackTraceString CrashInfo("Code generation");
1020     llvm::TimeTraceScope TimeScope("CodeGenPasses");
1021     CodeGenPasses.run(*TheModule);
1022   }
1023 
1024   if (ThinLinkOS)
1025     ThinLinkOS->keep();
1026   if (DwoOS)
1027     DwoOS->keep();
1028 }
1029 
1030 static PassBuilder::OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
1031   switch (Opts.OptimizationLevel) {
1032   default:
1033     llvm_unreachable("Invalid optimization level!");
1034 
1035   case 0:
1036     return PassBuilder::OptimizationLevel::O0;
1037 
1038   case 1:
1039     return PassBuilder::OptimizationLevel::O1;
1040 
1041   case 2:
1042     switch (Opts.OptimizeSize) {
1043     default:
1044       llvm_unreachable("Invalid optimization level for size!");
1045 
1046     case 0:
1047       return PassBuilder::OptimizationLevel::O2;
1048 
1049     case 1:
1050       return PassBuilder::OptimizationLevel::Os;
1051 
1052     case 2:
1053       return PassBuilder::OptimizationLevel::Oz;
1054     }
1055 
1056   case 3:
1057     return PassBuilder::OptimizationLevel::O3;
1058   }
1059 }
1060 
1061 /// A clean version of `EmitAssembly` that uses the new pass manager.
1062 ///
1063 /// Not all features are currently supported in this system, but where
1064 /// necessary it falls back to the legacy pass manager to at least provide
1065 /// basic functionality.
1066 ///
1067 /// This API is planned to have its functionality finished and then to replace
1068 /// `EmitAssembly` at some point in the future when the default switches.
1069 void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
1070     BackendAction Action, std::unique_ptr<raw_pwrite_stream> OS) {
1071   TimeRegion Region(CodeGenOpts.TimePasses ? &CodeGenerationTime : nullptr);
1072   setCommandLineOpts(CodeGenOpts);
1073 
1074   bool RequiresCodeGen = (Action != Backend_EmitNothing &&
1075                           Action != Backend_EmitBC &&
1076                           Action != Backend_EmitLL);
1077   CreateTargetMachine(RequiresCodeGen);
1078 
1079   if (RequiresCodeGen && !TM)
1080     return;
1081   if (TM)
1082     TheModule->setDataLayout(TM->createDataLayout());
1083 
1084   Optional<PGOOptions> PGOOpt;
1085 
1086   if (CodeGenOpts.hasProfileIRInstr())
1087     // -fprofile-generate.
1088     PGOOpt = PGOOptions(CodeGenOpts.InstrProfileOutput.empty()
1089                             ? std::string(DefaultProfileGenName)
1090                             : CodeGenOpts.InstrProfileOutput,
1091                         "", "", PGOOptions::IRInstr, PGOOptions::NoCSAction,
1092                         CodeGenOpts.DebugInfoForProfiling);
1093   else if (CodeGenOpts.hasProfileIRUse()) {
1094     // -fprofile-use.
1095     auto CSAction = CodeGenOpts.hasProfileCSIRUse() ? PGOOptions::CSIRUse
1096                                                     : PGOOptions::NoCSAction;
1097     PGOOpt = PGOOptions(CodeGenOpts.ProfileInstrumentUsePath, "",
1098                         CodeGenOpts.ProfileRemappingFile, PGOOptions::IRUse,
1099                         CSAction, CodeGenOpts.DebugInfoForProfiling);
1100   } else if (!CodeGenOpts.SampleProfileFile.empty())
1101     // -fprofile-sample-use
1102     PGOOpt = PGOOptions(
1103         CodeGenOpts.SampleProfileFile, "", CodeGenOpts.ProfileRemappingFile,
1104         PGOOptions::SampleUse, PGOOptions::NoCSAction,
1105         CodeGenOpts.DebugInfoForProfiling, CodeGenOpts.PseudoProbeForProfiling);
1106   else if (CodeGenOpts.PseudoProbeForProfiling)
1107     // -fpseudo-probe-for-profiling
1108     PGOOpt =
1109         PGOOptions("", "", "", PGOOptions::NoAction, PGOOptions::NoCSAction,
1110                    CodeGenOpts.DebugInfoForProfiling, true);
1111   else if (CodeGenOpts.DebugInfoForProfiling)
1112     // -fdebug-info-for-profiling
1113     PGOOpt = PGOOptions("", "", "", PGOOptions::NoAction,
1114                         PGOOptions::NoCSAction, true);
1115 
1116   // Check to see if we want to generate a CS profile.
1117   if (CodeGenOpts.hasProfileCSIRInstr()) {
1118     assert(!CodeGenOpts.hasProfileCSIRUse() &&
1119            "Cannot have both CSProfileUse pass and CSProfileGen pass at "
1120            "the same time");
1121     if (PGOOpt.hasValue()) {
1122       assert(PGOOpt->Action != PGOOptions::IRInstr &&
1123              PGOOpt->Action != PGOOptions::SampleUse &&
1124              "Cannot run CSProfileGen pass with ProfileGen or SampleUse "
1125              " pass");
1126       PGOOpt->CSProfileGenFile = CodeGenOpts.InstrProfileOutput.empty()
1127                                      ? std::string(DefaultProfileGenName)
1128                                      : CodeGenOpts.InstrProfileOutput;
1129       PGOOpt->CSAction = PGOOptions::CSIRInstr;
1130     } else
1131       PGOOpt = PGOOptions("",
1132                           CodeGenOpts.InstrProfileOutput.empty()
1133                               ? std::string(DefaultProfileGenName)
1134                               : CodeGenOpts.InstrProfileOutput,
1135                           "", PGOOptions::NoAction, PGOOptions::CSIRInstr,
1136                           CodeGenOpts.DebugInfoForProfiling);
1137   }
1138 
1139   PipelineTuningOptions PTO;
1140   PTO.LoopUnrolling = CodeGenOpts.UnrollLoops;
1141   // For historical reasons, loop interleaving is set to mirror setting for loop
1142   // unrolling.
1143   PTO.LoopInterleaving = CodeGenOpts.UnrollLoops;
1144   PTO.LoopVectorization = CodeGenOpts.VectorizeLoop;
1145   PTO.SLPVectorization = CodeGenOpts.VectorizeSLP;
1146   PTO.MergeFunctions = CodeGenOpts.MergeFunctions;
1147   // Only enable CGProfilePass when using integrated assembler, since
1148   // non-integrated assemblers don't recognize .cgprofile section.
1149   PTO.CallGraphProfile = !CodeGenOpts.DisableIntegratedAS;
1150   PTO.Coroutines = LangOpts.Coroutines;
1151   PTO.UniqueLinkageNames = CodeGenOpts.UniqueInternalLinkageNames;
1152 
1153   PassInstrumentationCallbacks PIC;
1154   StandardInstrumentations SI(CodeGenOpts.DebugPassManager);
1155   SI.registerCallbacks(PIC);
1156   PassBuilder PB(CodeGenOpts.DebugPassManager, TM.get(), PTO, PGOOpt, &PIC);
1157 
1158   // Attempt to load pass plugins and register their callbacks with PB.
1159   for (auto &PluginFN : CodeGenOpts.PassPlugins) {
1160     auto PassPlugin = PassPlugin::Load(PluginFN);
1161     if (PassPlugin) {
1162       PassPlugin->registerPassBuilderCallbacks(PB);
1163     } else {
1164       Diags.Report(diag::err_fe_unable_to_load_plugin)
1165           << PluginFN << toString(PassPlugin.takeError());
1166     }
1167   }
1168 #define HANDLE_EXTENSION(Ext)                                                  \
1169   get##Ext##PluginInfo().RegisterPassBuilderCallbacks(PB);
1170 #include "llvm/Support/Extension.def"
1171 
1172   LoopAnalysisManager LAM(CodeGenOpts.DebugPassManager);
1173   FunctionAnalysisManager FAM(CodeGenOpts.DebugPassManager);
1174   CGSCCAnalysisManager CGAM(CodeGenOpts.DebugPassManager);
1175   ModuleAnalysisManager MAM(CodeGenOpts.DebugPassManager);
1176 
1177   // Register the AA manager first so that our version is the one used.
1178   FAM.registerPass([&] { return PB.buildDefaultAAPipeline(); });
1179 
1180   // Register the target library analysis directly and give it a customized
1181   // preset TLI.
1182   Triple TargetTriple(TheModule->getTargetTriple());
1183   std::unique_ptr<TargetLibraryInfoImpl> TLII(
1184       createTLII(TargetTriple, CodeGenOpts));
1185   FAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); });
1186 
1187   // Register all the basic analyses with the managers.
1188   PB.registerModuleAnalyses(MAM);
1189   PB.registerCGSCCAnalyses(CGAM);
1190   PB.registerFunctionAnalyses(FAM);
1191   PB.registerLoopAnalyses(LAM);
1192   PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
1193 
1194   ModulePassManager MPM(CodeGenOpts.DebugPassManager);
1195 
1196   if (!CodeGenOpts.DisableLLVMPasses) {
1197     // Map our optimization levels into one of the distinct levels used to
1198     // configure the pipeline.
1199     PassBuilder::OptimizationLevel Level = mapToLevel(CodeGenOpts);
1200 
1201     bool IsThinLTO = CodeGenOpts.PrepareForThinLTO;
1202     bool IsLTO = CodeGenOpts.PrepareForLTO;
1203 
1204     if (LangOpts.ObjCAutoRefCount) {
1205       PB.registerPipelineStartEPCallback(
1206           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1207             if (Level != PassBuilder::OptimizationLevel::O0)
1208               MPM.addPass(
1209                   createModuleToFunctionPassAdaptor(ObjCARCExpandPass()));
1210           });
1211       PB.registerPipelineEarlySimplificationEPCallback(
1212           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1213             if (Level != PassBuilder::OptimizationLevel::O0)
1214               MPM.addPass(ObjCARCAPElimPass());
1215           });
1216       PB.registerScalarOptimizerLateEPCallback(
1217           [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
1218             if (Level != PassBuilder::OptimizationLevel::O0)
1219               FPM.addPass(ObjCARCOptPass());
1220           });
1221     }
1222 
1223     // If we reached here with a non-empty index file name, then the index
1224     // file was empty and we are not performing ThinLTO backend compilation
1225     // (used in testing in a distributed build environment). Drop any the type
1226     // test assume sequences inserted for whole program vtables so that
1227     // codegen doesn't complain.
1228     if (!CodeGenOpts.ThinLTOIndexFile.empty())
1229       PB.registerPipelineStartEPCallback(
1230           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1231             MPM.addPass(LowerTypeTestsPass(/*ExportSummary=*/nullptr,
1232                                            /*ImportSummary=*/nullptr,
1233                                            /*DropTypeTests=*/true));
1234           });
1235 
1236     if (Level != PassBuilder::OptimizationLevel::O0) {
1237       PB.registerPipelineStartEPCallback(
1238           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1239             MPM.addPass(createModuleToFunctionPassAdaptor(
1240                 EntryExitInstrumenterPass(/*PostInlining=*/false)));
1241           });
1242     }
1243 
1244     // Register callbacks to schedule sanitizer passes at the appropriate part
1245     // of the pipeline.
1246     if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
1247       PB.registerScalarOptimizerLateEPCallback(
1248           [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
1249             FPM.addPass(BoundsCheckingPass());
1250           });
1251 
1252     if (CodeGenOpts.SanitizeCoverageType ||
1253         CodeGenOpts.SanitizeCoverageIndirectCalls ||
1254         CodeGenOpts.SanitizeCoverageTraceCmp) {
1255       PB.registerOptimizerLastEPCallback(
1256           [this](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1257             auto SancovOpts = getSancovOptsFromCGOpts(CodeGenOpts);
1258             MPM.addPass(ModuleSanitizerCoveragePass(
1259                 SancovOpts, CodeGenOpts.SanitizeCoverageAllowlistFiles,
1260                 CodeGenOpts.SanitizeCoverageBlocklistFiles));
1261           });
1262     }
1263 
1264     if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
1265       int TrackOrigins = CodeGenOpts.SanitizeMemoryTrackOrigins;
1266       bool Recover = CodeGenOpts.SanitizeRecover.has(SanitizerKind::Memory);
1267       PB.registerOptimizerLastEPCallback(
1268           [TrackOrigins, Recover](ModulePassManager &MPM,
1269                                   PassBuilder::OptimizationLevel Level) {
1270             MPM.addPass(MemorySanitizerPass({TrackOrigins, Recover, false}));
1271             MPM.addPass(createModuleToFunctionPassAdaptor(
1272                 MemorySanitizerPass({TrackOrigins, Recover, false})));
1273           });
1274     }
1275     if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
1276       PB.registerOptimizerLastEPCallback(
1277           [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1278             MPM.addPass(ThreadSanitizerPass());
1279             MPM.addPass(
1280                 createModuleToFunctionPassAdaptor(ThreadSanitizerPass()));
1281           });
1282     }
1283 
1284     auto ASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
1285       if (LangOpts.Sanitize.has(Mask)) {
1286         bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
1287         bool UseAfterScope = CodeGenOpts.SanitizeAddressUseAfterScope;
1288         bool ModuleUseAfterScope = asanUseGlobalsGC(TargetTriple, CodeGenOpts);
1289         bool UseOdrIndicator = CodeGenOpts.SanitizeAddressUseOdrIndicator;
1290         PB.registerOptimizerLastEPCallback(
1291             [CompileKernel, Recover, UseAfterScope, ModuleUseAfterScope,
1292              UseOdrIndicator](ModulePassManager &MPM,
1293                               PassBuilder::OptimizationLevel Level) {
1294               MPM.addPass(
1295                   RequireAnalysisPass<ASanGlobalsMetadataAnalysis, Module>());
1296               MPM.addPass(ModuleAddressSanitizerPass(CompileKernel, Recover,
1297                                                      ModuleUseAfterScope,
1298                                                      UseOdrIndicator));
1299               MPM.addPass(createModuleToFunctionPassAdaptor(
1300                   AddressSanitizerPass(CompileKernel, Recover, UseAfterScope)));
1301             });
1302       }
1303     };
1304     ASanPass(SanitizerKind::Address, false);
1305     ASanPass(SanitizerKind::KernelAddress, true);
1306 
1307     auto HWASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
1308       if (LangOpts.Sanitize.has(Mask)) {
1309         bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
1310         PB.registerOptimizerLastEPCallback(
1311             [CompileKernel, Recover](ModulePassManager &MPM,
1312                                      PassBuilder::OptimizationLevel Level) {
1313               MPM.addPass(HWAddressSanitizerPass(CompileKernel, Recover));
1314             });
1315       }
1316     };
1317     HWASanPass(SanitizerKind::HWAddress, false);
1318     HWASanPass(SanitizerKind::KernelHWAddress, true);
1319 
1320     if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
1321       PB.registerOptimizerLastEPCallback(
1322           [this](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
1323             MPM.addPass(
1324                 DataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
1325           });
1326     }
1327 
1328     if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts, LangOpts))
1329       PB.registerPipelineStartEPCallback(
1330           [Options](ModulePassManager &MPM,
1331                     PassBuilder::OptimizationLevel Level) {
1332             MPM.addPass(GCOVProfilerPass(*Options));
1333           });
1334     if (Optional<InstrProfOptions> Options =
1335             getInstrProfOptions(CodeGenOpts, LangOpts))
1336       PB.registerPipelineStartEPCallback(
1337           [Options](ModulePassManager &MPM,
1338                     PassBuilder::OptimizationLevel Level) {
1339             MPM.addPass(InstrProfiling(*Options, false));
1340           });
1341 
1342     if (CodeGenOpts.OptimizationLevel == 0) {
1343       MPM = PB.buildO0DefaultPipeline(Level, IsLTO || IsThinLTO);
1344     } else if (IsThinLTO) {
1345       MPM = PB.buildThinLTOPreLinkDefaultPipeline(Level);
1346     } else if (IsLTO) {
1347       MPM = PB.buildLTOPreLinkDefaultPipeline(Level);
1348     } else {
1349       MPM = PB.buildPerModuleDefaultPipeline(Level);
1350     }
1351 
1352     if (!CodeGenOpts.MemoryProfileOutput.empty()) {
1353       MPM.addPass(createModuleToFunctionPassAdaptor(MemProfilerPass()));
1354       MPM.addPass(ModuleMemProfilerPass());
1355     }
1356   }
1357 
1358   // FIXME: We still use the legacy pass manager to do code generation. We
1359   // create that pass manager here and use it as needed below.
1360   legacy::PassManager CodeGenPasses;
1361   bool NeedCodeGen = false;
1362   std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
1363 
1364   // Append any output we need to the pass manager.
1365   switch (Action) {
1366   case Backend_EmitNothing:
1367     break;
1368 
1369   case Backend_EmitBC:
1370     if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
1371       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
1372         ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
1373         if (!ThinLinkOS)
1374           return;
1375       }
1376       TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1377                                CodeGenOpts.EnableSplitLTOUnit);
1378       MPM.addPass(ThinLTOBitcodeWriterPass(*OS, ThinLinkOS ? &ThinLinkOS->os()
1379                                                            : nullptr));
1380     } else {
1381       // Emit a module summary by default for Regular LTO except for ld64
1382       // targets
1383       bool EmitLTOSummary =
1384           (CodeGenOpts.PrepareForLTO &&
1385            !CodeGenOpts.DisableLLVMPasses &&
1386            llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
1387                llvm::Triple::Apple);
1388       if (EmitLTOSummary) {
1389         if (!TheModule->getModuleFlag("ThinLTO"))
1390           TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
1391         TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1392                                  uint32_t(1));
1393       }
1394       MPM.addPass(
1395           BitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
1396     }
1397     break;
1398 
1399   case Backend_EmitLL:
1400     MPM.addPass(PrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
1401     break;
1402 
1403   case Backend_EmitAssembly:
1404   case Backend_EmitMCNull:
1405   case Backend_EmitObj:
1406     NeedCodeGen = true;
1407     CodeGenPasses.add(
1408         createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
1409     if (!CodeGenOpts.SplitDwarfOutput.empty()) {
1410       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
1411       if (!DwoOS)
1412         return;
1413     }
1414     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
1415                        DwoOS ? &DwoOS->os() : nullptr))
1416       // FIXME: Should we handle this error differently?
1417       return;
1418     break;
1419   }
1420 
1421   // Before executing passes, print the final values of the LLVM options.
1422   cl::PrintOptionValues();
1423 
1424   // Now that we have all of the passes ready, run them.
1425   {
1426     PrettyStackTraceString CrashInfo("Optimizer");
1427     MPM.run(*TheModule, MAM);
1428   }
1429 
1430   // Now if needed, run the legacy PM for codegen.
1431   if (NeedCodeGen) {
1432     PrettyStackTraceString CrashInfo("Code generation");
1433     CodeGenPasses.run(*TheModule);
1434   }
1435 
1436   if (ThinLinkOS)
1437     ThinLinkOS->keep();
1438   if (DwoOS)
1439     DwoOS->keep();
1440 }
1441 
1442 static void runThinLTOBackend(
1443     DiagnosticsEngine &Diags, ModuleSummaryIndex *CombinedIndex, Module *M,
1444     const HeaderSearchOptions &HeaderOpts, const CodeGenOptions &CGOpts,
1445     const clang::TargetOptions &TOpts, const LangOptions &LOpts,
1446     std::unique_ptr<raw_pwrite_stream> OS, std::string SampleProfile,
1447     std::string ProfileRemapping, BackendAction Action) {
1448   StringMap<DenseMap<GlobalValue::GUID, GlobalValueSummary *>>
1449       ModuleToDefinedGVSummaries;
1450   CombinedIndex->collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries);
1451 
1452   setCommandLineOpts(CGOpts);
1453 
1454   // We can simply import the values mentioned in the combined index, since
1455   // we should only invoke this using the individual indexes written out
1456   // via a WriteIndexesThinBackend.
1457   FunctionImporter::ImportMapTy ImportList;
1458   std::vector<std::unique_ptr<llvm::MemoryBuffer>> OwnedImports;
1459   MapVector<llvm::StringRef, llvm::BitcodeModule> ModuleMap;
1460   if (!lto::loadReferencedModules(*M, *CombinedIndex, ImportList, ModuleMap,
1461                                   OwnedImports))
1462     return;
1463 
1464   auto AddStream = [&](size_t Task) {
1465     return std::make_unique<lto::NativeObjectStream>(std::move(OS));
1466   };
1467   lto::Config Conf;
1468   if (CGOpts.SaveTempsFilePrefix != "") {
1469     if (Error E = Conf.addSaveTemps(CGOpts.SaveTempsFilePrefix + ".",
1470                                     /* UseInputModulePath */ false)) {
1471       handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1472         errs() << "Error setting up ThinLTO save-temps: " << EIB.message()
1473                << '\n';
1474       });
1475     }
1476   }
1477   Conf.CPU = TOpts.CPU;
1478   Conf.CodeModel = getCodeModel(CGOpts);
1479   Conf.MAttrs = TOpts.Features;
1480   Conf.RelocModel = CGOpts.RelocationModel;
1481   Conf.CGOptLevel = getCGOptLevel(CGOpts);
1482   Conf.OptLevel = CGOpts.OptimizationLevel;
1483   initTargetOptions(Diags, Conf.Options, CGOpts, TOpts, LOpts, HeaderOpts);
1484   Conf.SampleProfile = std::move(SampleProfile);
1485   Conf.PTO.LoopUnrolling = CGOpts.UnrollLoops;
1486   // For historical reasons, loop interleaving is set to mirror setting for loop
1487   // unrolling.
1488   Conf.PTO.LoopInterleaving = CGOpts.UnrollLoops;
1489   Conf.PTO.LoopVectorization = CGOpts.VectorizeLoop;
1490   Conf.PTO.SLPVectorization = CGOpts.VectorizeSLP;
1491   // Only enable CGProfilePass when using integrated assembler, since
1492   // non-integrated assemblers don't recognize .cgprofile section.
1493   Conf.PTO.CallGraphProfile = !CGOpts.DisableIntegratedAS;
1494 
1495   // Context sensitive profile.
1496   if (CGOpts.hasProfileCSIRInstr()) {
1497     Conf.RunCSIRInstr = true;
1498     Conf.CSIRProfile = std::move(CGOpts.InstrProfileOutput);
1499   } else if (CGOpts.hasProfileCSIRUse()) {
1500     Conf.RunCSIRInstr = false;
1501     Conf.CSIRProfile = std::move(CGOpts.ProfileInstrumentUsePath);
1502   }
1503 
1504   Conf.ProfileRemapping = std::move(ProfileRemapping);
1505   Conf.UseNewPM = !CGOpts.LegacyPassManager;
1506   Conf.DebugPassManager = CGOpts.DebugPassManager;
1507   Conf.RemarksWithHotness = CGOpts.DiagnosticsWithHotness;
1508   Conf.RemarksFilename = CGOpts.OptRecordFile;
1509   Conf.RemarksPasses = CGOpts.OptRecordPasses;
1510   Conf.RemarksFormat = CGOpts.OptRecordFormat;
1511   Conf.SplitDwarfFile = CGOpts.SplitDwarfFile;
1512   Conf.SplitDwarfOutput = CGOpts.SplitDwarfOutput;
1513   switch (Action) {
1514   case Backend_EmitNothing:
1515     Conf.PreCodeGenModuleHook = [](size_t Task, const Module &Mod) {
1516       return false;
1517     };
1518     break;
1519   case Backend_EmitLL:
1520     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1521       M->print(*OS, nullptr, CGOpts.EmitLLVMUseLists);
1522       return false;
1523     };
1524     break;
1525   case Backend_EmitBC:
1526     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1527       WriteBitcodeToFile(*M, *OS, CGOpts.EmitLLVMUseLists);
1528       return false;
1529     };
1530     break;
1531   default:
1532     Conf.CGFileType = getCodeGenFileType(Action);
1533     break;
1534   }
1535   if (Error E =
1536           thinBackend(Conf, -1, AddStream, *M, *CombinedIndex, ImportList,
1537                       ModuleToDefinedGVSummaries[M->getModuleIdentifier()],
1538                       ModuleMap, CGOpts.CmdArgs)) {
1539     handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1540       errs() << "Error running ThinLTO backend: " << EIB.message() << '\n';
1541     });
1542   }
1543 }
1544 
1545 void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
1546                               const HeaderSearchOptions &HeaderOpts,
1547                               const CodeGenOptions &CGOpts,
1548                               const clang::TargetOptions &TOpts,
1549                               const LangOptions &LOpts,
1550                               const llvm::DataLayout &TDesc, Module *M,
1551                               BackendAction Action,
1552                               std::unique_ptr<raw_pwrite_stream> OS) {
1553 
1554   llvm::TimeTraceScope TimeScope("Backend");
1555 
1556   std::unique_ptr<llvm::Module> EmptyModule;
1557   if (!CGOpts.ThinLTOIndexFile.empty()) {
1558     // If we are performing a ThinLTO importing compile, load the function index
1559     // into memory and pass it into runThinLTOBackend, which will run the
1560     // function importer and invoke LTO passes.
1561     Expected<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
1562         llvm::getModuleSummaryIndexForFile(CGOpts.ThinLTOIndexFile,
1563                                            /*IgnoreEmptyThinLTOIndexFile*/true);
1564     if (!IndexOrErr) {
1565       logAllUnhandledErrors(IndexOrErr.takeError(), errs(),
1566                             "Error loading index file '" +
1567                             CGOpts.ThinLTOIndexFile + "': ");
1568       return;
1569     }
1570     std::unique_ptr<ModuleSummaryIndex> CombinedIndex = std::move(*IndexOrErr);
1571     // A null CombinedIndex means we should skip ThinLTO compilation
1572     // (LLVM will optionally ignore empty index files, returning null instead
1573     // of an error).
1574     if (CombinedIndex) {
1575       if (!CombinedIndex->skipModuleByDistributedBackend()) {
1576         runThinLTOBackend(Diags, CombinedIndex.get(), M, HeaderOpts, CGOpts,
1577                           TOpts, LOpts, std::move(OS), CGOpts.SampleProfileFile,
1578                           CGOpts.ProfileRemappingFile, Action);
1579         return;
1580       }
1581       // Distributed indexing detected that nothing from the module is needed
1582       // for the final linking. So we can skip the compilation. We sill need to
1583       // output an empty object file to make sure that a linker does not fail
1584       // trying to read it. Also for some features, like CFI, we must skip
1585       // the compilation as CombinedIndex does not contain all required
1586       // information.
1587       EmptyModule = std::make_unique<llvm::Module>("empty", M->getContext());
1588       EmptyModule->setTargetTriple(M->getTargetTriple());
1589       M = EmptyModule.get();
1590     }
1591   }
1592 
1593   EmitAssemblyHelper AsmHelper(Diags, HeaderOpts, CGOpts, TOpts, LOpts, M);
1594 
1595   if (!CGOpts.LegacyPassManager)
1596     AsmHelper.EmitAssemblyWithNewPassManager(Action, std::move(OS));
1597   else
1598     AsmHelper.EmitAssembly(Action, std::move(OS));
1599 
1600   // Verify clang's TargetInfo DataLayout against the LLVM TargetMachine's
1601   // DataLayout.
1602   if (AsmHelper.TM) {
1603     std::string DLDesc = M->getDataLayout().getStringRepresentation();
1604     if (DLDesc != TDesc.getStringRepresentation()) {
1605       unsigned DiagID = Diags.getCustomDiagID(
1606           DiagnosticsEngine::Error, "backend data layout '%0' does not match "
1607                                     "expected target description '%1'");
1608       Diags.Report(DiagID) << DLDesc << TDesc.getStringRepresentation();
1609     }
1610   }
1611 }
1612 
1613 // With -fembed-bitcode, save a copy of the llvm IR as data in the
1614 // __LLVM,__bitcode section.
1615 void clang::EmbedBitcode(llvm::Module *M, const CodeGenOptions &CGOpts,
1616                          llvm::MemoryBufferRef Buf) {
1617   if (CGOpts.getEmbedBitcode() == CodeGenOptions::Embed_Off)
1618     return;
1619   llvm::EmbedBitcodeInModule(
1620       *M, Buf, CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Marker,
1621       CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Bitcode,
1622       CGOpts.CmdArgs);
1623 }
1624