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