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/TargetLibraryInfo.h"
22 #include "llvm/Analysis/TargetTransformInfo.h"
23 #include "llvm/Bitcode/BitcodeReader.h"
24 #include "llvm/Bitcode/BitcodeWriter.h"
25 #include "llvm/Bitcode/BitcodeWriterPass.h"
26 #include "llvm/CodeGen/RegAllocRegistry.h"
27 #include "llvm/CodeGen/SchedulerRegistry.h"
28 #include "llvm/CodeGen/TargetSubtargetInfo.h"
29 #include "llvm/IR/DataLayout.h"
30 #include "llvm/IR/IRPrintingPasses.h"
31 #include "llvm/IR/LegacyPassManager.h"
32 #include "llvm/IR/Module.h"
33 #include "llvm/IR/ModuleSummaryIndex.h"
34 #include "llvm/IR/Verifier.h"
35 #include "llvm/LTO/LTOBackend.h"
36 #include "llvm/MC/MCAsmInfo.h"
37 #include "llvm/MC/SubtargetFeature.h"
38 #include "llvm/Passes/PassBuilder.h"
39 #include "llvm/Passes/PassPlugin.h"
40 #include "llvm/Passes/StandardInstrumentations.h"
41 #include "llvm/Support/BuryPointer.h"
42 #include "llvm/Support/CommandLine.h"
43 #include "llvm/Support/MemoryBuffer.h"
44 #include "llvm/Support/PrettyStackTrace.h"
45 #include "llvm/Support/TargetRegistry.h"
46 #include "llvm/Support/TimeProfiler.h"
47 #include "llvm/Support/Timer.h"
48 #include "llvm/Support/raw_ostream.h"
49 #include "llvm/Target/TargetMachine.h"
50 #include "llvm/Target/TargetOptions.h"
51 #include "llvm/Transforms/Coroutines.h"
52 #include "llvm/Transforms/Coroutines/CoroCleanup.h"
53 #include "llvm/Transforms/Coroutines/CoroEarly.h"
54 #include "llvm/Transforms/Coroutines/CoroElide.h"
55 #include "llvm/Transforms/Coroutines/CoroSplit.h"
56 #include "llvm/Transforms/IPO.h"
57 #include "llvm/Transforms/IPO/AlwaysInliner.h"
58 #include "llvm/Transforms/IPO/LowerTypeTests.h"
59 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
60 #include "llvm/Transforms/IPO/ThinLTOBitcodeWriter.h"
61 #include "llvm/Transforms/InstCombine/InstCombine.h"
62 #include "llvm/Transforms/Instrumentation.h"
63 #include "llvm/Transforms/Instrumentation/AddressSanitizer.h"
64 #include "llvm/Transforms/Instrumentation/BoundsChecking.h"
65 #include "llvm/Transforms/Instrumentation/GCOVProfiler.h"
66 #include "llvm/Transforms/Instrumentation/HWAddressSanitizer.h"
67 #include "llvm/Transforms/Instrumentation/InstrProfiling.h"
68 #include "llvm/Transforms/Instrumentation/MemorySanitizer.h"
69 #include "llvm/Transforms/Instrumentation/SanitizerCoverage.h"
70 #include "llvm/Transforms/Instrumentation/ThreadSanitizer.h"
71 #include "llvm/Transforms/ObjCARC.h"
72 #include "llvm/Transforms/Scalar.h"
73 #include "llvm/Transforms/Scalar/GVN.h"
74 #include "llvm/Transforms/Utils.h"
75 #include "llvm/Transforms/Utils/CanonicalizeAliases.h"
76 #include "llvm/Transforms/Utils/EntryExitInstrumenter.h"
77 #include "llvm/Transforms/Utils/NameAnonGlobals.h"
78 #include "llvm/Transforms/Utils/SymbolRewriter.h"
79 #include <memory>
80 using namespace clang;
81 using namespace llvm;
82 
83 #define HANDLE_EXTENSION(Ext)                                                  \
84   llvm::PassPluginLibraryInfo get##Ext##PluginInfo();
85 #include "llvm/Support/Extension.def"
86 
87 namespace {
88 
89 // Default filename used for profile generation.
90 static constexpr StringLiteral DefaultProfileGenName = "default_%m.profraw";
91 
92 class EmitAssemblyHelper {
93   DiagnosticsEngine &Diags;
94   const HeaderSearchOptions &HSOpts;
95   const CodeGenOptions &CodeGenOpts;
96   const clang::TargetOptions &TargetOpts;
97   const LangOptions &LangOpts;
98   Module *TheModule;
99 
100   Timer CodeGenerationTime;
101 
102   std::unique_ptr<raw_pwrite_stream> OS;
103 
104   TargetIRAnalysis getTargetIRAnalysis() const {
105     if (TM)
106       return TM->getTargetIRAnalysis();
107 
108     return TargetIRAnalysis();
109   }
110 
111   void CreatePasses(legacy::PassManager &MPM, legacy::FunctionPassManager &FPM);
112 
113   /// Generates the TargetMachine.
114   /// Leaves TM unchanged if it is unable to create the target machine.
115   /// Some of our clang tests specify triples which are not built
116   /// into clang. This is okay because these tests check the generated
117   /// IR, and they require DataLayout which depends on the triple.
118   /// In this case, we allow this method to fail and not report an error.
119   /// When MustCreateTM is used, we print an error if we are unable to load
120   /// the requested target.
121   void CreateTargetMachine(bool MustCreateTM);
122 
123   /// Add passes necessary to emit assembly or LLVM IR.
124   ///
125   /// \return True on success.
126   bool AddEmitPasses(legacy::PassManager &CodeGenPasses, BackendAction Action,
127                      raw_pwrite_stream &OS, raw_pwrite_stream *DwoOS);
128 
129   std::unique_ptr<llvm::ToolOutputFile> openOutputFile(StringRef Path) {
130     std::error_code EC;
131     auto F = std::make_unique<llvm::ToolOutputFile>(Path, EC,
132                                                      llvm::sys::fs::OF_None);
133     if (EC) {
134       Diags.Report(diag::err_fe_unable_to_open_output) << Path << EC.message();
135       F.reset();
136     }
137     return F;
138   }
139 
140 public:
141   EmitAssemblyHelper(DiagnosticsEngine &_Diags,
142                      const HeaderSearchOptions &HeaderSearchOpts,
143                      const CodeGenOptions &CGOpts,
144                      const clang::TargetOptions &TOpts,
145                      const LangOptions &LOpts, Module *M)
146       : Diags(_Diags), HSOpts(HeaderSearchOpts), CodeGenOpts(CGOpts),
147         TargetOpts(TOpts), LangOpts(LOpts), TheModule(M),
148         CodeGenerationTime("codegen", "Code Generation Time") {}
149 
150   ~EmitAssemblyHelper() {
151     if (CodeGenOpts.DisableFree)
152       BuryPointer(std::move(TM));
153   }
154 
155   std::unique_ptr<TargetMachine> TM;
156 
157   void EmitAssembly(BackendAction Action,
158                     std::unique_ptr<raw_pwrite_stream> OS);
159 
160   void EmitAssemblyWithNewPassManager(BackendAction Action,
161                                       std::unique_ptr<raw_pwrite_stream> OS);
162 };
163 
164 // We need this wrapper to access LangOpts and CGOpts from extension functions
165 // that we add to the PassManagerBuilder.
166 class PassManagerBuilderWrapper : public PassManagerBuilder {
167 public:
168   PassManagerBuilderWrapper(const Triple &TargetTriple,
169                             const CodeGenOptions &CGOpts,
170                             const LangOptions &LangOpts)
171       : PassManagerBuilder(), TargetTriple(TargetTriple), CGOpts(CGOpts),
172         LangOpts(LangOpts) {}
173   const Triple &getTargetTriple() const { return TargetTriple; }
174   const CodeGenOptions &getCGOpts() const { return CGOpts; }
175   const LangOptions &getLangOpts() const { return LangOpts; }
176 
177 private:
178   const Triple &TargetTriple;
179   const CodeGenOptions &CGOpts;
180   const LangOptions &LangOpts;
181 };
182 }
183 
184 static void addObjCARCAPElimPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
185   if (Builder.OptLevel > 0)
186     PM.add(createObjCARCAPElimPass());
187 }
188 
189 static void addObjCARCExpandPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
190   if (Builder.OptLevel > 0)
191     PM.add(createObjCARCExpandPass());
192 }
193 
194 static void addObjCARCOptPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
195   if (Builder.OptLevel > 0)
196     PM.add(createObjCARCOptPass());
197 }
198 
199 static void addAddDiscriminatorsPass(const PassManagerBuilder &Builder,
200                                      legacy::PassManagerBase &PM) {
201   PM.add(createAddDiscriminatorsPass());
202 }
203 
204 static void addBoundsCheckingPass(const PassManagerBuilder &Builder,
205                                   legacy::PassManagerBase &PM) {
206   PM.add(createBoundsCheckingLegacyPass());
207 }
208 
209 static SanitizerCoverageOptions
210 getSancovOptsFromCGOpts(const CodeGenOptions &CGOpts) {
211   SanitizerCoverageOptions Opts;
212   Opts.CoverageType =
213       static_cast<SanitizerCoverageOptions::Type>(CGOpts.SanitizeCoverageType);
214   Opts.IndirectCalls = CGOpts.SanitizeCoverageIndirectCalls;
215   Opts.TraceBB = CGOpts.SanitizeCoverageTraceBB;
216   Opts.TraceCmp = CGOpts.SanitizeCoverageTraceCmp;
217   Opts.TraceDiv = CGOpts.SanitizeCoverageTraceDiv;
218   Opts.TraceGep = CGOpts.SanitizeCoverageTraceGep;
219   Opts.Use8bitCounters = CGOpts.SanitizeCoverage8bitCounters;
220   Opts.TracePC = CGOpts.SanitizeCoverageTracePC;
221   Opts.TracePCGuard = CGOpts.SanitizeCoverageTracePCGuard;
222   Opts.NoPrune = CGOpts.SanitizeCoverageNoPrune;
223   Opts.Inline8bitCounters = CGOpts.SanitizeCoverageInline8bitCounters;
224   Opts.PCTable = CGOpts.SanitizeCoveragePCTable;
225   Opts.StackDepth = CGOpts.SanitizeCoverageStackDepth;
226   return Opts;
227 }
228 
229 static void addSanitizerCoveragePass(const PassManagerBuilder &Builder,
230                                      legacy::PassManagerBase &PM) {
231   const PassManagerBuilderWrapper &BuilderWrapper =
232       static_cast<const PassManagerBuilderWrapper &>(Builder);
233   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
234   auto Opts = getSancovOptsFromCGOpts(CGOpts);
235   PM.add(createModuleSanitizerCoverageLegacyPassPass(Opts));
236 }
237 
238 // Check if ASan should use GC-friendly instrumentation for globals.
239 // First of all, there is no point if -fdata-sections is off (expect for MachO,
240 // where this is not a factor). Also, on ELF this feature requires an assembler
241 // extension that only works with -integrated-as at the moment.
242 static bool asanUseGlobalsGC(const Triple &T, const CodeGenOptions &CGOpts) {
243   if (!CGOpts.SanitizeAddressGlobalsDeadStripping)
244     return false;
245   switch (T.getObjectFormat()) {
246   case Triple::MachO:
247   case Triple::COFF:
248     return true;
249   case Triple::ELF:
250     return CGOpts.DataSections && !CGOpts.DisableIntegratedAS;
251   case Triple::XCOFF:
252     llvm::report_fatal_error("ASan not implemented for XCOFF.");
253   case Triple::Wasm:
254   case Triple::UnknownObjectFormat:
255     break;
256   }
257   return false;
258 }
259 
260 static void addAddressSanitizerPasses(const PassManagerBuilder &Builder,
261                                       legacy::PassManagerBase &PM) {
262   const PassManagerBuilderWrapper &BuilderWrapper =
263       static_cast<const PassManagerBuilderWrapper&>(Builder);
264   const Triple &T = BuilderWrapper.getTargetTriple();
265   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
266   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Address);
267   bool UseAfterScope = CGOpts.SanitizeAddressUseAfterScope;
268   bool UseOdrIndicator = CGOpts.SanitizeAddressUseOdrIndicator;
269   bool UseGlobalsGC = asanUseGlobalsGC(T, CGOpts);
270   PM.add(createAddressSanitizerFunctionPass(/*CompileKernel*/ false, Recover,
271                                             UseAfterScope));
272   PM.add(createModuleAddressSanitizerLegacyPassPass(
273       /*CompileKernel*/ false, Recover, UseGlobalsGC, UseOdrIndicator));
274 }
275 
276 static void addKernelAddressSanitizerPasses(const PassManagerBuilder &Builder,
277                                             legacy::PassManagerBase &PM) {
278   PM.add(createAddressSanitizerFunctionPass(
279       /*CompileKernel*/ true, /*Recover*/ true, /*UseAfterScope*/ false));
280   PM.add(createModuleAddressSanitizerLegacyPassPass(
281       /*CompileKernel*/ true, /*Recover*/ true, /*UseGlobalsGC*/ true,
282       /*UseOdrIndicator*/ false));
283 }
284 
285 static void addHWAddressSanitizerPasses(const PassManagerBuilder &Builder,
286                                             legacy::PassManagerBase &PM) {
287   const PassManagerBuilderWrapper &BuilderWrapper =
288       static_cast<const PassManagerBuilderWrapper &>(Builder);
289   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
290   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::HWAddress);
291   PM.add(
292       createHWAddressSanitizerLegacyPassPass(/*CompileKernel*/ false, Recover));
293 }
294 
295 static void addKernelHWAddressSanitizerPasses(const PassManagerBuilder &Builder,
296                                             legacy::PassManagerBase &PM) {
297   PM.add(createHWAddressSanitizerLegacyPassPass(
298       /*CompileKernel*/ true, /*Recover*/ true));
299 }
300 
301 static void addGeneralOptsForMemorySanitizer(const PassManagerBuilder &Builder,
302                                              legacy::PassManagerBase &PM,
303                                              bool CompileKernel) {
304   const PassManagerBuilderWrapper &BuilderWrapper =
305       static_cast<const PassManagerBuilderWrapper&>(Builder);
306   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
307   int TrackOrigins = CGOpts.SanitizeMemoryTrackOrigins;
308   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Memory);
309   PM.add(createMemorySanitizerLegacyPassPass(
310       MemorySanitizerOptions{TrackOrigins, Recover, CompileKernel}));
311 
312   // MemorySanitizer inserts complex instrumentation that mostly follows
313   // the logic of the original code, but operates on "shadow" values.
314   // It can benefit from re-running some general purpose optimization passes.
315   if (Builder.OptLevel > 0) {
316     PM.add(createEarlyCSEPass());
317     PM.add(createReassociatePass());
318     PM.add(createLICMPass());
319     PM.add(createGVNPass());
320     PM.add(createInstructionCombiningPass());
321     PM.add(createDeadStoreEliminationPass());
322   }
323 }
324 
325 static void addMemorySanitizerPass(const PassManagerBuilder &Builder,
326                                    legacy::PassManagerBase &PM) {
327   addGeneralOptsForMemorySanitizer(Builder, PM, /*CompileKernel*/ false);
328 }
329 
330 static void addKernelMemorySanitizerPass(const PassManagerBuilder &Builder,
331                                          legacy::PassManagerBase &PM) {
332   addGeneralOptsForMemorySanitizer(Builder, PM, /*CompileKernel*/ true);
333 }
334 
335 static void addThreadSanitizerPass(const PassManagerBuilder &Builder,
336                                    legacy::PassManagerBase &PM) {
337   PM.add(createThreadSanitizerLegacyPassPass());
338 }
339 
340 static void addDataFlowSanitizerPass(const PassManagerBuilder &Builder,
341                                      legacy::PassManagerBase &PM) {
342   const PassManagerBuilderWrapper &BuilderWrapper =
343       static_cast<const PassManagerBuilderWrapper&>(Builder);
344   const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
345   PM.add(createDataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
346 }
347 
348 static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
349                                          const CodeGenOptions &CodeGenOpts) {
350   TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple);
351 
352   switch (CodeGenOpts.getVecLib()) {
353   case CodeGenOptions::Accelerate:
354     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::Accelerate);
355     break;
356   case CodeGenOptions::MASSV:
357     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::MASSV);
358     break;
359   case CodeGenOptions::SVML:
360     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::SVML);
361     break;
362   default:
363     break;
364   }
365   return TLII;
366 }
367 
368 static void addSymbolRewriterPass(const CodeGenOptions &Opts,
369                                   legacy::PassManager *MPM) {
370   llvm::SymbolRewriter::RewriteDescriptorList DL;
371 
372   llvm::SymbolRewriter::RewriteMapParser MapParser;
373   for (const auto &MapFile : Opts.RewriteMapFiles)
374     MapParser.parse(MapFile, &DL);
375 
376   MPM->add(createRewriteSymbolsPass(DL));
377 }
378 
379 static CodeGenOpt::Level getCGOptLevel(const CodeGenOptions &CodeGenOpts) {
380   switch (CodeGenOpts.OptimizationLevel) {
381   default:
382     llvm_unreachable("Invalid optimization level!");
383   case 0:
384     return CodeGenOpt::None;
385   case 1:
386     return CodeGenOpt::Less;
387   case 2:
388     return CodeGenOpt::Default; // O2/Os/Oz
389   case 3:
390     return CodeGenOpt::Aggressive;
391   }
392 }
393 
394 static Optional<llvm::CodeModel::Model>
395 getCodeModel(const CodeGenOptions &CodeGenOpts) {
396   unsigned CodeModel = llvm::StringSwitch<unsigned>(CodeGenOpts.CodeModel)
397                            .Case("tiny", llvm::CodeModel::Tiny)
398                            .Case("small", llvm::CodeModel::Small)
399                            .Case("kernel", llvm::CodeModel::Kernel)
400                            .Case("medium", llvm::CodeModel::Medium)
401                            .Case("large", llvm::CodeModel::Large)
402                            .Case("default", ~1u)
403                            .Default(~0u);
404   assert(CodeModel != ~0u && "invalid code model!");
405   if (CodeModel == ~1u)
406     return None;
407   return static_cast<llvm::CodeModel::Model>(CodeModel);
408 }
409 
410 static CodeGenFileType getCodeGenFileType(BackendAction Action) {
411   if (Action == Backend_EmitObj)
412     return CGFT_ObjectFile;
413   else if (Action == Backend_EmitMCNull)
414     return CGFT_Null;
415   else {
416     assert(Action == Backend_EmitAssembly && "Invalid action!");
417     return CGFT_AssemblyFile;
418   }
419 }
420 
421 static void initTargetOptions(llvm::TargetOptions &Options,
422                               const CodeGenOptions &CodeGenOpts,
423                               const clang::TargetOptions &TargetOpts,
424                               const LangOptions &LangOpts,
425                               const HeaderSearchOptions &HSOpts) {
426   Options.ThreadModel =
427       llvm::StringSwitch<llvm::ThreadModel::Model>(CodeGenOpts.ThreadModel)
428           .Case("posix", llvm::ThreadModel::POSIX)
429           .Case("single", llvm::ThreadModel::Single);
430 
431   // Set float ABI type.
432   assert((CodeGenOpts.FloatABI == "soft" || CodeGenOpts.FloatABI == "softfp" ||
433           CodeGenOpts.FloatABI == "hard" || CodeGenOpts.FloatABI.empty()) &&
434          "Invalid Floating Point ABI!");
435   Options.FloatABIType =
436       llvm::StringSwitch<llvm::FloatABI::ABIType>(CodeGenOpts.FloatABI)
437           .Case("soft", llvm::FloatABI::Soft)
438           .Case("softfp", llvm::FloatABI::Soft)
439           .Case("hard", llvm::FloatABI::Hard)
440           .Default(llvm::FloatABI::Default);
441 
442   // Set FP fusion mode.
443   switch (LangOpts.getDefaultFPContractMode()) {
444   case LangOptions::FPC_Off:
445     // Preserve any contraction performed by the front-end.  (Strict performs
446     // splitting of the muladd intrinsic in the backend.)
447     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
448     break;
449   case LangOptions::FPC_On:
450     Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
451     break;
452   case LangOptions::FPC_Fast:
453     Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
454     break;
455   }
456 
457   Options.UseInitArray = CodeGenOpts.UseInitArray;
458   Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
459   Options.CompressDebugSections = CodeGenOpts.getCompressDebugSections();
460   Options.RelaxELFRelocations = CodeGenOpts.RelaxELFRelocations;
461 
462   // Set EABI version.
463   Options.EABIVersion = TargetOpts.EABIVersion;
464 
465   if (LangOpts.SjLjExceptions)
466     Options.ExceptionModel = llvm::ExceptionHandling::SjLj;
467   if (LangOpts.SEHExceptions)
468     Options.ExceptionModel = llvm::ExceptionHandling::WinEH;
469   if (LangOpts.DWARFExceptions)
470     Options.ExceptionModel = llvm::ExceptionHandling::DwarfCFI;
471   if (LangOpts.WasmExceptions)
472     Options.ExceptionModel = llvm::ExceptionHandling::Wasm;
473 
474   Options.NoInfsFPMath = CodeGenOpts.NoInfsFPMath;
475   Options.NoNaNsFPMath = CodeGenOpts.NoNaNsFPMath;
476   Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
477   Options.UnsafeFPMath = CodeGenOpts.UnsafeFPMath;
478   Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
479   Options.FunctionSections = CodeGenOpts.FunctionSections;
480   Options.DataSections = CodeGenOpts.DataSections;
481   Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
482   Options.TLSSize = CodeGenOpts.TLSSize;
483   Options.EmulatedTLS = CodeGenOpts.EmulatedTLS;
484   Options.ExplicitEmulatedTLS = CodeGenOpts.ExplicitEmulatedTLS;
485   Options.DebuggerTuning = CodeGenOpts.getDebuggerTuning();
486   Options.EmitStackSizeSection = CodeGenOpts.StackSizeSection;
487   Options.EmitAddrsig = CodeGenOpts.Addrsig;
488   Options.ForceDwarfFrameSection = CodeGenOpts.ForceDwarfFrameSection;
489 
490   Options.MCOptions.SplitDwarfFile = CodeGenOpts.SplitDwarfFile;
491   Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
492   Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
493   Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
494   Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
495   Options.MCOptions.MCIncrementalLinkerCompatible =
496       CodeGenOpts.IncrementalLinkerCompatible;
497   Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
498   Options.MCOptions.MCNoWarn = CodeGenOpts.NoWarn;
499   Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
500   Options.MCOptions.PreserveAsmComments = CodeGenOpts.PreserveAsmComments;
501   Options.MCOptions.ABIName = TargetOpts.ABI;
502   for (const auto &Entry : HSOpts.UserEntries)
503     if (!Entry.IsFramework &&
504         (Entry.Group == frontend::IncludeDirGroup::Quoted ||
505          Entry.Group == frontend::IncludeDirGroup::Angled ||
506          Entry.Group == frontend::IncludeDirGroup::System))
507       Options.MCOptions.IASSearchPaths.push_back(
508           Entry.IgnoreSysRoot ? Entry.Path : HSOpts.Sysroot + Entry.Path);
509 }
510 static Optional<GCOVOptions> getGCOVOptions(const CodeGenOptions &CodeGenOpts) {
511   if (CodeGenOpts.DisableGCov)
512     return None;
513   if (!CodeGenOpts.EmitGcovArcs && !CodeGenOpts.EmitGcovNotes)
514     return None;
515   // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
516   // LLVM's -default-gcov-version flag is set to something invalid.
517   GCOVOptions Options;
518   Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
519   Options.EmitData = CodeGenOpts.EmitGcovArcs;
520   llvm::copy(CodeGenOpts.CoverageVersion, std::begin(Options.Version));
521   Options.UseCfgChecksum = CodeGenOpts.CoverageExtraChecksum;
522   Options.NoRedZone = CodeGenOpts.DisableRedZone;
523   Options.FunctionNamesInData = !CodeGenOpts.CoverageNoFunctionNamesInData;
524   Options.Filter = CodeGenOpts.ProfileFilterFiles;
525   Options.Exclude = CodeGenOpts.ProfileExcludeFiles;
526   Options.ExitBlockBeforeBody = CodeGenOpts.CoverageExitBlockBeforeBody;
527   return Options;
528 }
529 
530 static Optional<InstrProfOptions>
531 getInstrProfOptions(const CodeGenOptions &CodeGenOpts,
532                     const LangOptions &LangOpts) {
533   if (!CodeGenOpts.hasProfileClangInstr())
534     return None;
535   InstrProfOptions Options;
536   Options.NoRedZone = CodeGenOpts.DisableRedZone;
537   Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
538 
539   // TODO: Surface the option to emit atomic profile counter increments at
540   // the driver level.
541   Options.Atomic = LangOpts.Sanitize.has(SanitizerKind::Thread);
542   return Options;
543 }
544 
545 void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
546                                       legacy::FunctionPassManager &FPM) {
547   // Handle disabling of all LLVM passes, where we want to preserve the
548   // internal module before any optimization.
549   if (CodeGenOpts.DisableLLVMPasses)
550     return;
551 
552   // Figure out TargetLibraryInfo.  This needs to be added to MPM and FPM
553   // manually (and not via PMBuilder), since some passes (eg. InstrProfiling)
554   // are inserted before PMBuilder ones - they'd get the default-constructed
555   // TLI with an unknown target otherwise.
556   Triple TargetTriple(TheModule->getTargetTriple());
557   std::unique_ptr<TargetLibraryInfoImpl> TLII(
558       createTLII(TargetTriple, CodeGenOpts));
559 
560   // If we reached here with a non-empty index file name, then the index file
561   // was empty and we are not performing ThinLTO backend compilation (used in
562   // testing in a distributed build environment). Drop any the type test
563   // assume sequences inserted for whole program vtables so that codegen doesn't
564   // complain.
565   if (!CodeGenOpts.ThinLTOIndexFile.empty())
566     MPM.add(createLowerTypeTestsPass(/*ExportSummary=*/nullptr,
567                                      /*ImportSummary=*/nullptr,
568                                      /*DropTypeTests=*/true));
569 
570   PassManagerBuilderWrapper PMBuilder(TargetTriple, CodeGenOpts, LangOpts);
571 
572   // At O0 and O1 we only run the always inliner which is more efficient. At
573   // higher optimization levels we run the normal inliner.
574   if (CodeGenOpts.OptimizationLevel <= 1) {
575     bool InsertLifetimeIntrinsics = (CodeGenOpts.OptimizationLevel != 0 &&
576                                      !CodeGenOpts.DisableLifetimeMarkers);
577     PMBuilder.Inliner = createAlwaysInlinerLegacyPass(InsertLifetimeIntrinsics);
578   } else {
579     // We do not want to inline hot callsites for SamplePGO module-summary build
580     // because profile annotation will happen again in ThinLTO backend, and we
581     // want the IR of the hot path to match the profile.
582     PMBuilder.Inliner = createFunctionInliningPass(
583         CodeGenOpts.OptimizationLevel, CodeGenOpts.OptimizeSize,
584         (!CodeGenOpts.SampleProfileFile.empty() &&
585          CodeGenOpts.PrepareForThinLTO));
586   }
587 
588   PMBuilder.OptLevel = CodeGenOpts.OptimizationLevel;
589   PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
590   PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
591   PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
592 
593   PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
594   // Loop interleaving in the loop vectorizer has historically been set to be
595   // enabled when loop unrolling is enabled.
596   PMBuilder.LoopsInterleaved = CodeGenOpts.UnrollLoops;
597   PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
598   PMBuilder.PrepareForThinLTO = CodeGenOpts.PrepareForThinLTO;
599   PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
600   PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
601 
602   MPM.add(new TargetLibraryInfoWrapperPass(*TLII));
603 
604   if (TM)
605     TM->adjustPassManager(PMBuilder);
606 
607   if (CodeGenOpts.DebugInfoForProfiling ||
608       !CodeGenOpts.SampleProfileFile.empty())
609     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
610                            addAddDiscriminatorsPass);
611 
612   // In ObjC ARC mode, add the main ARC optimization passes.
613   if (LangOpts.ObjCAutoRefCount) {
614     PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
615                            addObjCARCExpandPass);
616     PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
617                            addObjCARCAPElimPass);
618     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
619                            addObjCARCOptPass);
620   }
621 
622   if (LangOpts.Coroutines)
623     addCoroutinePassesToExtensionPoints(PMBuilder);
624 
625   if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds)) {
626     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
627                            addBoundsCheckingPass);
628     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
629                            addBoundsCheckingPass);
630   }
631 
632   if (CodeGenOpts.SanitizeCoverageType ||
633       CodeGenOpts.SanitizeCoverageIndirectCalls ||
634       CodeGenOpts.SanitizeCoverageTraceCmp) {
635     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
636                            addSanitizerCoveragePass);
637     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
638                            addSanitizerCoveragePass);
639   }
640 
641   if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
642     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
643                            addAddressSanitizerPasses);
644     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
645                            addAddressSanitizerPasses);
646   }
647 
648   if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
649     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
650                            addKernelAddressSanitizerPasses);
651     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
652                            addKernelAddressSanitizerPasses);
653   }
654 
655   if (LangOpts.Sanitize.has(SanitizerKind::HWAddress)) {
656     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
657                            addHWAddressSanitizerPasses);
658     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
659                            addHWAddressSanitizerPasses);
660   }
661 
662   if (LangOpts.Sanitize.has(SanitizerKind::KernelHWAddress)) {
663     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
664                            addKernelHWAddressSanitizerPasses);
665     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
666                            addKernelHWAddressSanitizerPasses);
667   }
668 
669   if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
670     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
671                            addMemorySanitizerPass);
672     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
673                            addMemorySanitizerPass);
674   }
675 
676   if (LangOpts.Sanitize.has(SanitizerKind::KernelMemory)) {
677     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
678                            addKernelMemorySanitizerPass);
679     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
680                            addKernelMemorySanitizerPass);
681   }
682 
683   if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
684     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
685                            addThreadSanitizerPass);
686     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
687                            addThreadSanitizerPass);
688   }
689 
690   if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
691     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
692                            addDataFlowSanitizerPass);
693     PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
694                            addDataFlowSanitizerPass);
695   }
696 
697   // Set up the per-function pass manager.
698   FPM.add(new TargetLibraryInfoWrapperPass(*TLII));
699   if (CodeGenOpts.VerifyModule)
700     FPM.add(createVerifierPass());
701 
702   // Set up the per-module pass manager.
703   if (!CodeGenOpts.RewriteMapFiles.empty())
704     addSymbolRewriterPass(CodeGenOpts, &MPM);
705 
706   if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts)) {
707     MPM.add(createGCOVProfilerPass(*Options));
708     if (CodeGenOpts.getDebugInfo() == codegenoptions::NoDebugInfo)
709       MPM.add(createStripSymbolsPass(true));
710   }
711 
712   if (Optional<InstrProfOptions> Options =
713           getInstrProfOptions(CodeGenOpts, LangOpts))
714     MPM.add(createInstrProfilingLegacyPass(*Options, false));
715 
716   bool hasIRInstr = false;
717   if (CodeGenOpts.hasProfileIRInstr()) {
718     PMBuilder.EnablePGOInstrGen = true;
719     hasIRInstr = true;
720   }
721   if (CodeGenOpts.hasProfileCSIRInstr()) {
722     assert(!CodeGenOpts.hasProfileCSIRUse() &&
723            "Cannot have both CSProfileUse pass and CSProfileGen pass at the "
724            "same time");
725     assert(!hasIRInstr &&
726            "Cannot have both ProfileGen pass and CSProfileGen pass at the "
727            "same time");
728     PMBuilder.EnablePGOCSInstrGen = true;
729     hasIRInstr = true;
730   }
731   if (hasIRInstr) {
732     if (!CodeGenOpts.InstrProfileOutput.empty())
733       PMBuilder.PGOInstrGen = CodeGenOpts.InstrProfileOutput;
734     else
735       PMBuilder.PGOInstrGen = std::string(DefaultProfileGenName);
736   }
737   if (CodeGenOpts.hasProfileIRUse()) {
738     PMBuilder.PGOInstrUse = CodeGenOpts.ProfileInstrumentUsePath;
739     PMBuilder.EnablePGOCSInstrUse = CodeGenOpts.hasProfileCSIRUse();
740   }
741 
742   if (!CodeGenOpts.SampleProfileFile.empty())
743     PMBuilder.PGOSampleUse = CodeGenOpts.SampleProfileFile;
744 
745   PMBuilder.populateFunctionPassManager(FPM);
746   PMBuilder.populateModulePassManager(MPM);
747 }
748 
749 static void setCommandLineOpts(const CodeGenOptions &CodeGenOpts) {
750   SmallVector<const char *, 16> BackendArgs;
751   BackendArgs.push_back("clang"); // Fake program name.
752   if (!CodeGenOpts.DebugPass.empty()) {
753     BackendArgs.push_back("-debug-pass");
754     BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
755   }
756   if (!CodeGenOpts.LimitFloatPrecision.empty()) {
757     BackendArgs.push_back("-limit-float-precision");
758     BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
759   }
760   BackendArgs.push_back(nullptr);
761   llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
762                                     BackendArgs.data());
763 }
764 
765 void EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
766   // Create the TargetMachine for generating code.
767   std::string Error;
768   std::string Triple = TheModule->getTargetTriple();
769   const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
770   if (!TheTarget) {
771     if (MustCreateTM)
772       Diags.Report(diag::err_fe_unable_to_create_target) << Error;
773     return;
774   }
775 
776   Optional<llvm::CodeModel::Model> CM = getCodeModel(CodeGenOpts);
777   std::string FeaturesStr =
778       llvm::join(TargetOpts.Features.begin(), TargetOpts.Features.end(), ",");
779   llvm::Reloc::Model RM = CodeGenOpts.RelocationModel;
780   CodeGenOpt::Level OptLevel = getCGOptLevel(CodeGenOpts);
781 
782   llvm::TargetOptions Options;
783   initTargetOptions(Options, CodeGenOpts, TargetOpts, LangOpts, HSOpts);
784   TM.reset(TheTarget->createTargetMachine(Triple, TargetOpts.CPU, FeaturesStr,
785                                           Options, RM, CM, OptLevel));
786 }
787 
788 bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
789                                        BackendAction Action,
790                                        raw_pwrite_stream &OS,
791                                        raw_pwrite_stream *DwoOS) {
792   // Add LibraryInfo.
793   llvm::Triple TargetTriple(TheModule->getTargetTriple());
794   std::unique_ptr<TargetLibraryInfoImpl> TLII(
795       createTLII(TargetTriple, CodeGenOpts));
796   CodeGenPasses.add(new TargetLibraryInfoWrapperPass(*TLII));
797 
798   // Normal mode, emit a .s or .o file by running the code generator. Note,
799   // this also adds codegenerator level optimization passes.
800   CodeGenFileType CGFT = getCodeGenFileType(Action);
801 
802   // Add ObjC ARC final-cleanup optimizations. This is done as part of the
803   // "codegen" passes so that it isn't run multiple times when there is
804   // inlining happening.
805   if (CodeGenOpts.OptimizationLevel > 0)
806     CodeGenPasses.add(createObjCARCContractPass());
807 
808   if (TM->addPassesToEmitFile(CodeGenPasses, OS, DwoOS, CGFT,
809                               /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
810     Diags.Report(diag::err_fe_unable_to_interface_with_target);
811     return false;
812   }
813 
814   return true;
815 }
816 
817 void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
818                                       std::unique_ptr<raw_pwrite_stream> OS) {
819   TimeRegion Region(FrontendTimesIsEnabled ? &CodeGenerationTime : nullptr);
820 
821   setCommandLineOpts(CodeGenOpts);
822 
823   bool UsesCodeGen = (Action != Backend_EmitNothing &&
824                       Action != Backend_EmitBC &&
825                       Action != Backend_EmitLL);
826   CreateTargetMachine(UsesCodeGen);
827 
828   if (UsesCodeGen && !TM)
829     return;
830   if (TM)
831     TheModule->setDataLayout(TM->createDataLayout());
832 
833   legacy::PassManager PerModulePasses;
834   PerModulePasses.add(
835       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
836 
837   legacy::FunctionPassManager PerFunctionPasses(TheModule);
838   PerFunctionPasses.add(
839       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
840 
841   CreatePasses(PerModulePasses, PerFunctionPasses);
842 
843   legacy::PassManager CodeGenPasses;
844   CodeGenPasses.add(
845       createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
846 
847   std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
848 
849   switch (Action) {
850   case Backend_EmitNothing:
851     break;
852 
853   case Backend_EmitBC:
854     if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
855       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
856         ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
857         if (!ThinLinkOS)
858           return;
859       }
860       TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
861                                CodeGenOpts.EnableSplitLTOUnit);
862       PerModulePasses.add(createWriteThinLTOBitcodePass(
863           *OS, ThinLinkOS ? &ThinLinkOS->os() : nullptr));
864     } else {
865       // Emit a module summary by default for Regular LTO except for ld64
866       // targets
867       bool EmitLTOSummary =
868           (CodeGenOpts.PrepareForLTO &&
869            !CodeGenOpts.DisableLLVMPasses &&
870            llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
871                llvm::Triple::Apple);
872       if (EmitLTOSummary) {
873         if (!TheModule->getModuleFlag("ThinLTO"))
874           TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
875         TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
876                                  uint32_t(1));
877       }
878 
879       PerModulePasses.add(createBitcodeWriterPass(
880           *OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
881     }
882     break;
883 
884   case Backend_EmitLL:
885     PerModulePasses.add(
886         createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
887     break;
888 
889   default:
890     if (!CodeGenOpts.SplitDwarfOutput.empty()) {
891       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
892       if (!DwoOS)
893         return;
894     }
895     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
896                        DwoOS ? &DwoOS->os() : nullptr))
897       return;
898   }
899 
900   // Before executing passes, print the final values of the LLVM options.
901   cl::PrintOptionValues();
902 
903   // Run passes. For now we do all passes at once, but eventually we
904   // would like to have the option of streaming code generation.
905 
906   {
907     PrettyStackTraceString CrashInfo("Per-function optimization");
908     llvm::TimeTraceScope TimeScope("PerFunctionPasses");
909 
910     PerFunctionPasses.doInitialization();
911     for (Function &F : *TheModule)
912       if (!F.isDeclaration())
913         PerFunctionPasses.run(F);
914     PerFunctionPasses.doFinalization();
915   }
916 
917   {
918     PrettyStackTraceString CrashInfo("Per-module optimization passes");
919     llvm::TimeTraceScope TimeScope("PerModulePasses");
920     PerModulePasses.run(*TheModule);
921   }
922 
923   {
924     PrettyStackTraceString CrashInfo("Code generation");
925     llvm::TimeTraceScope TimeScope("CodeGenPasses");
926     CodeGenPasses.run(*TheModule);
927   }
928 
929   if (ThinLinkOS)
930     ThinLinkOS->keep();
931   if (DwoOS)
932     DwoOS->keep();
933 }
934 
935 static PassBuilder::OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
936   switch (Opts.OptimizationLevel) {
937   default:
938     llvm_unreachable("Invalid optimization level!");
939 
940   case 1:
941     return PassBuilder::OptimizationLevel::O1;
942 
943   case 2:
944     switch (Opts.OptimizeSize) {
945     default:
946       llvm_unreachable("Invalid optimization level for size!");
947 
948     case 0:
949       return PassBuilder::OptimizationLevel::O2;
950 
951     case 1:
952       return PassBuilder::OptimizationLevel::Os;
953 
954     case 2:
955       return PassBuilder::OptimizationLevel::Oz;
956     }
957 
958   case 3:
959     return PassBuilder::OptimizationLevel::O3;
960   }
961 }
962 
963 static void addCoroutinePassesAtO0(ModulePassManager &MPM,
964                                    const LangOptions &LangOpts,
965                                    const CodeGenOptions &CodeGenOpts) {
966   if (!LangOpts.Coroutines)
967     return;
968 
969   MPM.addPass(createModuleToFunctionPassAdaptor(CoroEarlyPass()));
970 
971   CGSCCPassManager CGPM(CodeGenOpts.DebugPassManager);
972   CGPM.addPass(CoroSplitPass());
973   CGPM.addPass(createCGSCCToFunctionPassAdaptor(CoroElidePass()));
974   MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(std::move(CGPM)));
975 
976   MPM.addPass(createModuleToFunctionPassAdaptor(CoroCleanupPass()));
977 }
978 
979 static void addSanitizersAtO0(ModulePassManager &MPM,
980                               const Triple &TargetTriple,
981                               const LangOptions &LangOpts,
982                               const CodeGenOptions &CodeGenOpts) {
983   auto ASanPass = [&](SanitizerMask Mask, bool CompileKernel) {
984     MPM.addPass(RequireAnalysisPass<ASanGlobalsMetadataAnalysis, Module>());
985     bool Recover = CodeGenOpts.SanitizeRecover.has(Mask);
986     MPM.addPass(createModuleToFunctionPassAdaptor(AddressSanitizerPass(
987         CompileKernel, Recover, CodeGenOpts.SanitizeAddressUseAfterScope)));
988     bool ModuleUseAfterScope = asanUseGlobalsGC(TargetTriple, CodeGenOpts);
989     MPM.addPass(
990         ModuleAddressSanitizerPass(CompileKernel, Recover, ModuleUseAfterScope,
991                                    CodeGenOpts.SanitizeAddressUseOdrIndicator));
992   };
993 
994   if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
995     ASanPass(SanitizerKind::Address, /*CompileKernel=*/false);
996   }
997 
998   if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
999     ASanPass(SanitizerKind::KernelAddress, /*CompileKernel=*/true);
1000   }
1001 
1002   if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
1003     MPM.addPass(MemorySanitizerPass({}));
1004     MPM.addPass(createModuleToFunctionPassAdaptor(MemorySanitizerPass({})));
1005   }
1006 
1007   if (LangOpts.Sanitize.has(SanitizerKind::KernelMemory)) {
1008     MPM.addPass(createModuleToFunctionPassAdaptor(
1009         MemorySanitizerPass({0, false, /*Kernel=*/true})));
1010   }
1011 
1012   if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
1013     MPM.addPass(ThreadSanitizerPass());
1014     MPM.addPass(createModuleToFunctionPassAdaptor(ThreadSanitizerPass()));
1015   }
1016 }
1017 
1018 /// A clean version of `EmitAssembly` that uses the new pass manager.
1019 ///
1020 /// Not all features are currently supported in this system, but where
1021 /// necessary it falls back to the legacy pass manager to at least provide
1022 /// basic functionality.
1023 ///
1024 /// This API is planned to have its functionality finished and then to replace
1025 /// `EmitAssembly` at some point in the future when the default switches.
1026 void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
1027     BackendAction Action, std::unique_ptr<raw_pwrite_stream> OS) {
1028   TimeRegion Region(FrontendTimesIsEnabled ? &CodeGenerationTime : nullptr);
1029   setCommandLineOpts(CodeGenOpts);
1030 
1031   bool RequiresCodeGen = (Action != Backend_EmitNothing &&
1032                           Action != Backend_EmitBC &&
1033                           Action != Backend_EmitLL);
1034   CreateTargetMachine(RequiresCodeGen);
1035 
1036   if (RequiresCodeGen && !TM)
1037     return;
1038   if (TM)
1039     TheModule->setDataLayout(TM->createDataLayout());
1040 
1041   Optional<PGOOptions> PGOOpt;
1042 
1043   if (CodeGenOpts.hasProfileIRInstr())
1044     // -fprofile-generate.
1045     PGOOpt = PGOOptions(CodeGenOpts.InstrProfileOutput.empty()
1046                             ? std::string(DefaultProfileGenName)
1047                             : CodeGenOpts.InstrProfileOutput,
1048                         "", "", PGOOptions::IRInstr, PGOOptions::NoCSAction,
1049                         CodeGenOpts.DebugInfoForProfiling);
1050   else if (CodeGenOpts.hasProfileIRUse()) {
1051     // -fprofile-use.
1052     auto CSAction = CodeGenOpts.hasProfileCSIRUse() ? PGOOptions::CSIRUse
1053                                                     : PGOOptions::NoCSAction;
1054     PGOOpt = PGOOptions(CodeGenOpts.ProfileInstrumentUsePath, "",
1055                         CodeGenOpts.ProfileRemappingFile, PGOOptions::IRUse,
1056                         CSAction, CodeGenOpts.DebugInfoForProfiling);
1057   } else if (!CodeGenOpts.SampleProfileFile.empty())
1058     // -fprofile-sample-use
1059     PGOOpt =
1060         PGOOptions(CodeGenOpts.SampleProfileFile, "",
1061                    CodeGenOpts.ProfileRemappingFile, PGOOptions::SampleUse,
1062                    PGOOptions::NoCSAction, CodeGenOpts.DebugInfoForProfiling);
1063   else if (CodeGenOpts.DebugInfoForProfiling)
1064     // -fdebug-info-for-profiling
1065     PGOOpt = PGOOptions("", "", "", PGOOptions::NoAction,
1066                         PGOOptions::NoCSAction, true);
1067 
1068   // Check to see if we want to generate a CS profile.
1069   if (CodeGenOpts.hasProfileCSIRInstr()) {
1070     assert(!CodeGenOpts.hasProfileCSIRUse() &&
1071            "Cannot have both CSProfileUse pass and CSProfileGen pass at "
1072            "the same time");
1073     if (PGOOpt.hasValue()) {
1074       assert(PGOOpt->Action != PGOOptions::IRInstr &&
1075              PGOOpt->Action != PGOOptions::SampleUse &&
1076              "Cannot run CSProfileGen pass with ProfileGen or SampleUse "
1077              " pass");
1078       PGOOpt->CSProfileGenFile = CodeGenOpts.InstrProfileOutput.empty()
1079                                      ? std::string(DefaultProfileGenName)
1080                                      : CodeGenOpts.InstrProfileOutput;
1081       PGOOpt->CSAction = PGOOptions::CSIRInstr;
1082     } else
1083       PGOOpt = PGOOptions("",
1084                           CodeGenOpts.InstrProfileOutput.empty()
1085                               ? std::string(DefaultProfileGenName)
1086                               : CodeGenOpts.InstrProfileOutput,
1087                           "", PGOOptions::NoAction, PGOOptions::CSIRInstr,
1088                           CodeGenOpts.DebugInfoForProfiling);
1089   }
1090 
1091   PipelineTuningOptions PTO;
1092   PTO.LoopUnrolling = CodeGenOpts.UnrollLoops;
1093   // For historical reasons, loop interleaving is set to mirror setting for loop
1094   // unrolling.
1095   PTO.LoopInterleaving = CodeGenOpts.UnrollLoops;
1096   PTO.LoopVectorization = CodeGenOpts.VectorizeLoop;
1097   PTO.SLPVectorization = CodeGenOpts.VectorizeSLP;
1098   PTO.Coroutines = LangOpts.Coroutines;
1099 
1100   PassInstrumentationCallbacks PIC;
1101   StandardInstrumentations SI;
1102   SI.registerCallbacks(PIC);
1103   PassBuilder PB(TM.get(), PTO, PGOOpt, &PIC);
1104 
1105   // Attempt to load pass plugins and register their callbacks with PB.
1106   for (auto &PluginFN : CodeGenOpts.PassPlugins) {
1107     auto PassPlugin = PassPlugin::Load(PluginFN);
1108     if (PassPlugin) {
1109       PassPlugin->registerPassBuilderCallbacks(PB);
1110     } else {
1111       Diags.Report(diag::err_fe_unable_to_load_plugin)
1112           << PluginFN << toString(PassPlugin.takeError());
1113     }
1114   }
1115 #define HANDLE_EXTENSION(Ext)                                                  \
1116   get##Ext##PluginInfo().RegisterPassBuilderCallbacks(PB);
1117 #include "llvm/Support/Extension.def"
1118 
1119   LoopAnalysisManager LAM(CodeGenOpts.DebugPassManager);
1120   FunctionAnalysisManager FAM(CodeGenOpts.DebugPassManager);
1121   CGSCCAnalysisManager CGAM(CodeGenOpts.DebugPassManager);
1122   ModuleAnalysisManager MAM(CodeGenOpts.DebugPassManager);
1123 
1124   // Register the AA manager first so that our version is the one used.
1125   FAM.registerPass([&] { return PB.buildDefaultAAPipeline(); });
1126 
1127   // Register the target library analysis directly and give it a customized
1128   // preset TLI.
1129   Triple TargetTriple(TheModule->getTargetTriple());
1130   std::unique_ptr<TargetLibraryInfoImpl> TLII(
1131       createTLII(TargetTriple, CodeGenOpts));
1132   FAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); });
1133 
1134   // Register all the basic analyses with the managers.
1135   PB.registerModuleAnalyses(MAM);
1136   PB.registerCGSCCAnalyses(CGAM);
1137   PB.registerFunctionAnalyses(FAM);
1138   PB.registerLoopAnalyses(LAM);
1139   PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
1140 
1141   ModulePassManager MPM(CodeGenOpts.DebugPassManager);
1142 
1143   if (!CodeGenOpts.DisableLLVMPasses) {
1144     bool IsThinLTO = CodeGenOpts.PrepareForThinLTO;
1145     bool IsLTO = CodeGenOpts.PrepareForLTO;
1146 
1147     if (CodeGenOpts.OptimizationLevel == 0) {
1148       // If we reached here with a non-empty index file name, then the index
1149       // file was empty and we are not performing ThinLTO backend compilation
1150       // (used in testing in a distributed build environment). Drop any the type
1151       // test assume sequences inserted for whole program vtables so that
1152       // codegen doesn't complain.
1153       if (!CodeGenOpts.ThinLTOIndexFile.empty())
1154         MPM.addPass(LowerTypeTestsPass(/*ExportSummary=*/nullptr,
1155                                        /*ImportSummary=*/nullptr,
1156                                        /*DropTypeTests=*/true));
1157       if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts))
1158         MPM.addPass(GCOVProfilerPass(*Options));
1159       if (Optional<InstrProfOptions> Options =
1160               getInstrProfOptions(CodeGenOpts, LangOpts))
1161         MPM.addPass(InstrProfiling(*Options, false));
1162 
1163       // Build a minimal pipeline based on the semantics required by Clang,
1164       // which is just that always inlining occurs. Further, disable generating
1165       // lifetime intrinsics to avoid enabling further optimizations during
1166       // code generation.
1167       MPM.addPass(AlwaysInlinerPass(/*InsertLifetimeIntrinsics=*/false));
1168 
1169       // At -O0, we can still do PGO. Add all the requested passes for
1170       // instrumentation PGO, if requested.
1171       if (PGOOpt && (PGOOpt->Action == PGOOptions::IRInstr ||
1172                      PGOOpt->Action == PGOOptions::IRUse))
1173         PB.addPGOInstrPassesForO0(
1174             MPM, CodeGenOpts.DebugPassManager,
1175             /* RunProfileGen */ (PGOOpt->Action == PGOOptions::IRInstr),
1176             /* IsCS */ false, PGOOpt->ProfileFile,
1177             PGOOpt->ProfileRemappingFile);
1178 
1179       // At -O0 we directly run necessary sanitizer passes.
1180       if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
1181         MPM.addPass(createModuleToFunctionPassAdaptor(BoundsCheckingPass()));
1182 
1183       // Lastly, add semantically necessary passes for LTO.
1184       if (IsLTO || IsThinLTO) {
1185         MPM.addPass(CanonicalizeAliasesPass());
1186         MPM.addPass(NameAnonGlobalPass());
1187       }
1188     } else {
1189       // Map our optimization levels into one of the distinct levels used to
1190       // configure the pipeline.
1191       PassBuilder::OptimizationLevel Level = mapToLevel(CodeGenOpts);
1192 
1193       // If we reached here with a non-empty index file name, then the index
1194       // file was empty and we are not performing ThinLTO backend compilation
1195       // (used in testing in a distributed build environment). Drop any the type
1196       // test assume sequences inserted for whole program vtables so that
1197       // codegen doesn't complain.
1198       if (!CodeGenOpts.ThinLTOIndexFile.empty())
1199         PB.registerPipelineStartEPCallback([](ModulePassManager &MPM) {
1200           MPM.addPass(LowerTypeTestsPass(/*ExportSummary=*/nullptr,
1201                                          /*ImportSummary=*/nullptr,
1202                                          /*DropTypeTests=*/true));
1203         });
1204 
1205       PB.registerPipelineStartEPCallback([](ModulePassManager &MPM) {
1206         MPM.addPass(createModuleToFunctionPassAdaptor(
1207             EntryExitInstrumenterPass(/*PostInlining=*/false)));
1208       });
1209 
1210       // Register callbacks to schedule sanitizer passes at the appropriate part of
1211       // the pipeline.
1212       // FIXME: either handle asan/the remaining sanitizers or error out
1213       if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
1214         PB.registerScalarOptimizerLateEPCallback(
1215             [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
1216               FPM.addPass(BoundsCheckingPass());
1217             });
1218       if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
1219         PB.registerPipelineStartEPCallback([](ModulePassManager &MPM) {
1220           MPM.addPass(MemorySanitizerPass({}));
1221         });
1222         PB.registerOptimizerLastEPCallback(
1223             [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
1224               FPM.addPass(MemorySanitizerPass({}));
1225             });
1226       }
1227       if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
1228         PB.registerPipelineStartEPCallback(
1229             [](ModulePassManager &MPM) { MPM.addPass(ThreadSanitizerPass()); });
1230         PB.registerOptimizerLastEPCallback(
1231             [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
1232               FPM.addPass(ThreadSanitizerPass());
1233             });
1234       }
1235       if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
1236         PB.registerPipelineStartEPCallback([&](ModulePassManager &MPM) {
1237           MPM.addPass(
1238               RequireAnalysisPass<ASanGlobalsMetadataAnalysis, Module>());
1239         });
1240         bool Recover = CodeGenOpts.SanitizeRecover.has(SanitizerKind::Address);
1241         bool UseAfterScope = CodeGenOpts.SanitizeAddressUseAfterScope;
1242         PB.registerOptimizerLastEPCallback(
1243             [Recover, UseAfterScope](FunctionPassManager &FPM,
1244                                      PassBuilder::OptimizationLevel Level) {
1245               FPM.addPass(AddressSanitizerPass(
1246                   /*CompileKernel=*/false, Recover, UseAfterScope));
1247             });
1248         bool ModuleUseAfterScope = asanUseGlobalsGC(TargetTriple, CodeGenOpts);
1249         bool UseOdrIndicator = CodeGenOpts.SanitizeAddressUseOdrIndicator;
1250         PB.registerPipelineStartEPCallback(
1251             [Recover, ModuleUseAfterScope,
1252              UseOdrIndicator](ModulePassManager &MPM) {
1253               MPM.addPass(ModuleAddressSanitizerPass(
1254                   /*CompileKernel=*/false, Recover, ModuleUseAfterScope,
1255                   UseOdrIndicator));
1256             });
1257       }
1258       if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts))
1259         PB.registerPipelineStartEPCallback([Options](ModulePassManager &MPM) {
1260           MPM.addPass(GCOVProfilerPass(*Options));
1261         });
1262       if (Optional<InstrProfOptions> Options =
1263               getInstrProfOptions(CodeGenOpts, LangOpts))
1264         PB.registerPipelineStartEPCallback([Options](ModulePassManager &MPM) {
1265           MPM.addPass(InstrProfiling(*Options, false));
1266         });
1267 
1268       if (IsThinLTO) {
1269         MPM = PB.buildThinLTOPreLinkDefaultPipeline(
1270             Level, CodeGenOpts.DebugPassManager);
1271         MPM.addPass(CanonicalizeAliasesPass());
1272         MPM.addPass(NameAnonGlobalPass());
1273       } else if (IsLTO) {
1274         MPM = PB.buildLTOPreLinkDefaultPipeline(Level,
1275                                                 CodeGenOpts.DebugPassManager);
1276         MPM.addPass(CanonicalizeAliasesPass());
1277         MPM.addPass(NameAnonGlobalPass());
1278       } else {
1279         MPM = PB.buildPerModuleDefaultPipeline(Level,
1280                                                CodeGenOpts.DebugPassManager);
1281       }
1282     }
1283 
1284     if (CodeGenOpts.SanitizeCoverageType ||
1285         CodeGenOpts.SanitizeCoverageIndirectCalls ||
1286         CodeGenOpts.SanitizeCoverageTraceCmp) {
1287       auto SancovOpts = getSancovOptsFromCGOpts(CodeGenOpts);
1288       MPM.addPass(ModuleSanitizerCoveragePass(SancovOpts));
1289     }
1290 
1291     if (LangOpts.Sanitize.has(SanitizerKind::HWAddress)) {
1292       bool Recover = CodeGenOpts.SanitizeRecover.has(SanitizerKind::HWAddress);
1293       MPM.addPass(HWAddressSanitizerPass(
1294           /*CompileKernel=*/false, Recover));
1295     }
1296     if (LangOpts.Sanitize.has(SanitizerKind::KernelHWAddress)) {
1297       MPM.addPass(HWAddressSanitizerPass(
1298           /*CompileKernel=*/true, /*Recover=*/true));
1299     }
1300 
1301     if (CodeGenOpts.OptimizationLevel == 0) {
1302       addCoroutinePassesAtO0(MPM, LangOpts, CodeGenOpts);
1303       addSanitizersAtO0(MPM, TargetTriple, LangOpts, CodeGenOpts);
1304     }
1305   }
1306 
1307   // FIXME: We still use the legacy pass manager to do code generation. We
1308   // create that pass manager here and use it as needed below.
1309   legacy::PassManager CodeGenPasses;
1310   bool NeedCodeGen = false;
1311   std::unique_ptr<llvm::ToolOutputFile> ThinLinkOS, DwoOS;
1312 
1313   // Append any output we need to the pass manager.
1314   switch (Action) {
1315   case Backend_EmitNothing:
1316     break;
1317 
1318   case Backend_EmitBC:
1319     if (CodeGenOpts.PrepareForThinLTO && !CodeGenOpts.DisableLLVMPasses) {
1320       if (!CodeGenOpts.ThinLinkBitcodeFile.empty()) {
1321         ThinLinkOS = openOutputFile(CodeGenOpts.ThinLinkBitcodeFile);
1322         if (!ThinLinkOS)
1323           return;
1324       }
1325       TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1326                                CodeGenOpts.EnableSplitLTOUnit);
1327       MPM.addPass(ThinLTOBitcodeWriterPass(*OS, ThinLinkOS ? &ThinLinkOS->os()
1328                                                            : nullptr));
1329     } else {
1330       // Emit a module summary by default for Regular LTO except for ld64
1331       // targets
1332       bool EmitLTOSummary =
1333           (CodeGenOpts.PrepareForLTO &&
1334            !CodeGenOpts.DisableLLVMPasses &&
1335            llvm::Triple(TheModule->getTargetTriple()).getVendor() !=
1336                llvm::Triple::Apple);
1337       if (EmitLTOSummary) {
1338         if (!TheModule->getModuleFlag("ThinLTO"))
1339           TheModule->addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
1340         TheModule->addModuleFlag(Module::Error, "EnableSplitLTOUnit",
1341                                  uint32_t(1));
1342       }
1343       MPM.addPass(
1344           BitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists, EmitLTOSummary));
1345     }
1346     break;
1347 
1348   case Backend_EmitLL:
1349     MPM.addPass(PrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
1350     break;
1351 
1352   case Backend_EmitAssembly:
1353   case Backend_EmitMCNull:
1354   case Backend_EmitObj:
1355     NeedCodeGen = true;
1356     CodeGenPasses.add(
1357         createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
1358     if (!CodeGenOpts.SplitDwarfOutput.empty()) {
1359       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
1360       if (!DwoOS)
1361         return;
1362     }
1363     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
1364                        DwoOS ? &DwoOS->os() : nullptr))
1365       // FIXME: Should we handle this error differently?
1366       return;
1367     break;
1368   }
1369 
1370   // Before executing passes, print the final values of the LLVM options.
1371   cl::PrintOptionValues();
1372 
1373   // Now that we have all of the passes ready, run them.
1374   {
1375     PrettyStackTraceString CrashInfo("Optimizer");
1376     MPM.run(*TheModule, MAM);
1377   }
1378 
1379   // Now if needed, run the legacy PM for codegen.
1380   if (NeedCodeGen) {
1381     PrettyStackTraceString CrashInfo("Code generation");
1382     CodeGenPasses.run(*TheModule);
1383   }
1384 
1385   if (ThinLinkOS)
1386     ThinLinkOS->keep();
1387   if (DwoOS)
1388     DwoOS->keep();
1389 }
1390 
1391 Expected<BitcodeModule> clang::FindThinLTOModule(MemoryBufferRef MBRef) {
1392   Expected<std::vector<BitcodeModule>> BMsOrErr = getBitcodeModuleList(MBRef);
1393   if (!BMsOrErr)
1394     return BMsOrErr.takeError();
1395 
1396   // The bitcode file may contain multiple modules, we want the one that is
1397   // marked as being the ThinLTO module.
1398   if (const BitcodeModule *Bm = FindThinLTOModule(*BMsOrErr))
1399     return *Bm;
1400 
1401   return make_error<StringError>("Could not find module summary",
1402                                  inconvertibleErrorCode());
1403 }
1404 
1405 BitcodeModule *clang::FindThinLTOModule(MutableArrayRef<BitcodeModule> BMs) {
1406   for (BitcodeModule &BM : BMs) {
1407     Expected<BitcodeLTOInfo> LTOInfo = BM.getLTOInfo();
1408     if (LTOInfo && LTOInfo->IsThinLTO)
1409       return &BM;
1410   }
1411   return nullptr;
1412 }
1413 
1414 static void runThinLTOBackend(ModuleSummaryIndex *CombinedIndex, Module *M,
1415                               const HeaderSearchOptions &HeaderOpts,
1416                               const CodeGenOptions &CGOpts,
1417                               const clang::TargetOptions &TOpts,
1418                               const LangOptions &LOpts,
1419                               std::unique_ptr<raw_pwrite_stream> OS,
1420                               std::string SampleProfile,
1421                               std::string ProfileRemapping,
1422                               BackendAction Action) {
1423   StringMap<DenseMap<GlobalValue::GUID, GlobalValueSummary *>>
1424       ModuleToDefinedGVSummaries;
1425   CombinedIndex->collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries);
1426 
1427   setCommandLineOpts(CGOpts);
1428 
1429   // We can simply import the values mentioned in the combined index, since
1430   // we should only invoke this using the individual indexes written out
1431   // via a WriteIndexesThinBackend.
1432   FunctionImporter::ImportMapTy ImportList;
1433   for (auto &GlobalList : *CombinedIndex) {
1434     // Ignore entries for undefined references.
1435     if (GlobalList.second.SummaryList.empty())
1436       continue;
1437 
1438     auto GUID = GlobalList.first;
1439     for (auto &Summary : GlobalList.second.SummaryList) {
1440       // Skip the summaries for the importing module. These are included to
1441       // e.g. record required linkage changes.
1442       if (Summary->modulePath() == M->getModuleIdentifier())
1443         continue;
1444       // Add an entry to provoke importing by thinBackend.
1445       ImportList[Summary->modulePath()].insert(GUID);
1446     }
1447   }
1448 
1449   std::vector<std::unique_ptr<llvm::MemoryBuffer>> OwnedImports;
1450   MapVector<llvm::StringRef, llvm::BitcodeModule> ModuleMap;
1451 
1452   for (auto &I : ImportList) {
1453     ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> MBOrErr =
1454         llvm::MemoryBuffer::getFile(I.first());
1455     if (!MBOrErr) {
1456       errs() << "Error loading imported file '" << I.first()
1457              << "': " << MBOrErr.getError().message() << "\n";
1458       return;
1459     }
1460 
1461     Expected<BitcodeModule> BMOrErr = FindThinLTOModule(**MBOrErr);
1462     if (!BMOrErr) {
1463       handleAllErrors(BMOrErr.takeError(), [&](ErrorInfoBase &EIB) {
1464         errs() << "Error loading imported file '" << I.first()
1465                << "': " << EIB.message() << '\n';
1466       });
1467       return;
1468     }
1469     ModuleMap.insert({I.first(), *BMOrErr});
1470 
1471     OwnedImports.push_back(std::move(*MBOrErr));
1472   }
1473   auto AddStream = [&](size_t Task) {
1474     return std::make_unique<lto::NativeObjectStream>(std::move(OS));
1475   };
1476   lto::Config Conf;
1477   if (CGOpts.SaveTempsFilePrefix != "") {
1478     if (Error E = Conf.addSaveTemps(CGOpts.SaveTempsFilePrefix + ".",
1479                                     /* UseInputModulePath */ false)) {
1480       handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1481         errs() << "Error setting up ThinLTO save-temps: " << EIB.message()
1482                << '\n';
1483       });
1484     }
1485   }
1486   Conf.CPU = TOpts.CPU;
1487   Conf.CodeModel = getCodeModel(CGOpts);
1488   Conf.MAttrs = TOpts.Features;
1489   Conf.RelocModel = CGOpts.RelocationModel;
1490   Conf.CGOptLevel = getCGOptLevel(CGOpts);
1491   Conf.OptLevel = CGOpts.OptimizationLevel;
1492   initTargetOptions(Conf.Options, CGOpts, TOpts, LOpts, HeaderOpts);
1493   Conf.SampleProfile = std::move(SampleProfile);
1494   Conf.PTO.LoopUnrolling = CGOpts.UnrollLoops;
1495   // For historical reasons, loop interleaving is set to mirror setting for loop
1496   // unrolling.
1497   Conf.PTO.LoopInterleaving = CGOpts.UnrollLoops;
1498   Conf.PTO.LoopVectorization = CGOpts.VectorizeLoop;
1499   Conf.PTO.SLPVectorization = CGOpts.VectorizeSLP;
1500 
1501   // Context sensitive profile.
1502   if (CGOpts.hasProfileCSIRInstr()) {
1503     Conf.RunCSIRInstr = true;
1504     Conf.CSIRProfile = std::move(CGOpts.InstrProfileOutput);
1505   } else if (CGOpts.hasProfileCSIRUse()) {
1506     Conf.RunCSIRInstr = false;
1507     Conf.CSIRProfile = std::move(CGOpts.ProfileInstrumentUsePath);
1508   }
1509 
1510   Conf.ProfileRemapping = std::move(ProfileRemapping);
1511   Conf.UseNewPM = CGOpts.ExperimentalNewPassManager;
1512   Conf.DebugPassManager = CGOpts.DebugPassManager;
1513   Conf.RemarksWithHotness = CGOpts.DiagnosticsWithHotness;
1514   Conf.RemarksFilename = CGOpts.OptRecordFile;
1515   Conf.RemarksPasses = CGOpts.OptRecordPasses;
1516   Conf.RemarksFormat = CGOpts.OptRecordFormat;
1517   Conf.SplitDwarfFile = CGOpts.SplitDwarfFile;
1518   Conf.SplitDwarfOutput = CGOpts.SplitDwarfOutput;
1519   switch (Action) {
1520   case Backend_EmitNothing:
1521     Conf.PreCodeGenModuleHook = [](size_t Task, const Module &Mod) {
1522       return false;
1523     };
1524     break;
1525   case Backend_EmitLL:
1526     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1527       M->print(*OS, nullptr, CGOpts.EmitLLVMUseLists);
1528       return false;
1529     };
1530     break;
1531   case Backend_EmitBC:
1532     Conf.PreCodeGenModuleHook = [&](size_t Task, const Module &Mod) {
1533       WriteBitcodeToFile(*M, *OS, CGOpts.EmitLLVMUseLists);
1534       return false;
1535     };
1536     break;
1537   default:
1538     Conf.CGFileType = getCodeGenFileType(Action);
1539     break;
1540   }
1541   if (Error E = thinBackend(
1542           Conf, -1, AddStream, *M, *CombinedIndex, ImportList,
1543           ModuleToDefinedGVSummaries[M->getModuleIdentifier()], ModuleMap)) {
1544     handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
1545       errs() << "Error running ThinLTO backend: " << EIB.message() << '\n';
1546     });
1547   }
1548 }
1549 
1550 void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
1551                               const HeaderSearchOptions &HeaderOpts,
1552                               const CodeGenOptions &CGOpts,
1553                               const clang::TargetOptions &TOpts,
1554                               const LangOptions &LOpts,
1555                               const llvm::DataLayout &TDesc, Module *M,
1556                               BackendAction Action,
1557                               std::unique_ptr<raw_pwrite_stream> OS) {
1558 
1559   llvm::TimeTraceScope TimeScope("Backend");
1560 
1561   std::unique_ptr<llvm::Module> EmptyModule;
1562   if (!CGOpts.ThinLTOIndexFile.empty()) {
1563     // If we are performing a ThinLTO importing compile, load the function index
1564     // into memory and pass it into runThinLTOBackend, which will run the
1565     // function importer and invoke LTO passes.
1566     Expected<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
1567         llvm::getModuleSummaryIndexForFile(CGOpts.ThinLTOIndexFile,
1568                                            /*IgnoreEmptyThinLTOIndexFile*/true);
1569     if (!IndexOrErr) {
1570       logAllUnhandledErrors(IndexOrErr.takeError(), errs(),
1571                             "Error loading index file '" +
1572                             CGOpts.ThinLTOIndexFile + "': ");
1573       return;
1574     }
1575     std::unique_ptr<ModuleSummaryIndex> CombinedIndex = std::move(*IndexOrErr);
1576     // A null CombinedIndex means we should skip ThinLTO compilation
1577     // (LLVM will optionally ignore empty index files, returning null instead
1578     // of an error).
1579     if (CombinedIndex) {
1580       if (!CombinedIndex->skipModuleByDistributedBackend()) {
1581         runThinLTOBackend(CombinedIndex.get(), M, HeaderOpts, CGOpts, TOpts,
1582                           LOpts, std::move(OS), CGOpts.SampleProfileFile,
1583                           CGOpts.ProfileRemappingFile, Action);
1584         return;
1585       }
1586       // Distributed indexing detected that nothing from the module is needed
1587       // for the final linking. So we can skip the compilation. We sill need to
1588       // output an empty object file to make sure that a linker does not fail
1589       // trying to read it. Also for some features, like CFI, we must skip
1590       // the compilation as CombinedIndex does not contain all required
1591       // information.
1592       EmptyModule = std::make_unique<llvm::Module>("empty", M->getContext());
1593       EmptyModule->setTargetTriple(M->getTargetTriple());
1594       M = EmptyModule.get();
1595     }
1596   }
1597 
1598   EmitAssemblyHelper AsmHelper(Diags, HeaderOpts, CGOpts, TOpts, LOpts, M);
1599 
1600   if (CGOpts.ExperimentalNewPassManager)
1601     AsmHelper.EmitAssemblyWithNewPassManager(Action, std::move(OS));
1602   else
1603     AsmHelper.EmitAssembly(Action, std::move(OS));
1604 
1605   // Verify clang's TargetInfo DataLayout against the LLVM TargetMachine's
1606   // DataLayout.
1607   if (AsmHelper.TM) {
1608     std::string DLDesc = M->getDataLayout().getStringRepresentation();
1609     if (DLDesc != TDesc.getStringRepresentation()) {
1610       unsigned DiagID = Diags.getCustomDiagID(
1611           DiagnosticsEngine::Error, "backend data layout '%0' does not match "
1612                                     "expected target description '%1'");
1613       Diags.Report(DiagID) << DLDesc << TDesc.getStringRepresentation();
1614     }
1615   }
1616 }
1617 
1618 // With -fembed-bitcode, save a copy of the llvm IR as data in the
1619 // __LLVM,__bitcode section.
1620 void clang::EmbedBitcode(llvm::Module *M, const CodeGenOptions &CGOpts,
1621                          llvm::MemoryBufferRef Buf) {
1622   if (CGOpts.getEmbedBitcode() == CodeGenOptions::Embed_Off)
1623     return;
1624   llvm::EmbedBitcodeInModule(
1625       *M, Buf, CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Marker,
1626       CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Bitcode,
1627       &CGOpts.CmdArgs);
1628 }
1629