clang  3.9.0
BackendUtil.cpp
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1 //===--- BackendUtil.cpp - LLVM Backend Utilities -------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
11 #include "clang/Basic/Diagnostic.h"
16 #include "clang/Frontend/Utils.h"
17 #include "llvm/ADT/StringExtras.h"
18 #include "llvm/ADT/StringSwitch.h"
19 #include "llvm/ADT/Triple.h"
20 #include "llvm/Analysis/TargetLibraryInfo.h"
21 #include "llvm/Analysis/TargetTransformInfo.h"
22 #include "llvm/Bitcode/BitcodeWriterPass.h"
23 #include "llvm/Bitcode/ReaderWriter.h"
24 #include "llvm/CodeGen/RegAllocRegistry.h"
25 #include "llvm/CodeGen/SchedulerRegistry.h"
26 #include "llvm/IR/DataLayout.h"
27 #include "llvm/IR/ModuleSummaryIndex.h"
28 #include "llvm/IR/IRPrintingPasses.h"
29 #include "llvm/IR/LegacyPassManager.h"
30 #include "llvm/IR/Module.h"
31 #include "llvm/IR/Verifier.h"
32 #include "llvm/MC/SubtargetFeature.h"
33 #include "llvm/Object/ModuleSummaryIndexObjectFile.h"
34 #include "llvm/Support/CommandLine.h"
35 #include "llvm/Support/PrettyStackTrace.h"
36 #include "llvm/Support/TargetRegistry.h"
37 #include "llvm/Support/Timer.h"
38 #include "llvm/Support/raw_ostream.h"
39 #include "llvm/Target/TargetMachine.h"
40 #include "llvm/Target/TargetOptions.h"
41 #include "llvm/Target/TargetSubtargetInfo.h"
42 #include "llvm/Transforms/IPO.h"
43 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
44 #include "llvm/Transforms/Instrumentation.h"
45 #include "llvm/Transforms/ObjCARC.h"
46 #include "llvm/Transforms/Scalar.h"
47 #include "llvm/Transforms/Scalar/GVN.h"
48 #include "llvm/Transforms/Utils/SymbolRewriter.h"
49 #include <memory>
50 using namespace clang;
51 using namespace llvm;
52 
53 namespace {
54 
55 class EmitAssemblyHelper {
56  DiagnosticsEngine &Diags;
57  const CodeGenOptions &CodeGenOpts;
58  const clang::TargetOptions &TargetOpts;
59  const LangOptions &LangOpts;
60  Module *TheModule;
61 
62  Timer CodeGenerationTime;
63 
64  std::unique_ptr<raw_pwrite_stream> OS;
65 
66 private:
67  TargetIRAnalysis getTargetIRAnalysis() const {
68  if (TM)
69  return TM->getTargetIRAnalysis();
70 
71  return TargetIRAnalysis();
72  }
73 
74  /// Set LLVM command line options passed through -backend-option.
75  void setCommandLineOpts();
76 
77  void CreatePasses(legacy::PassManager &MPM, legacy::FunctionPassManager &FPM,
78  ModuleSummaryIndex *ModuleSummary);
79 
80  /// Generates the TargetMachine.
81  /// Leaves TM unchanged if it is unable to create the target machine.
82  /// Some of our clang tests specify triples which are not built
83  /// into clang. This is okay because these tests check the generated
84  /// IR, and they require DataLayout which depends on the triple.
85  /// In this case, we allow this method to fail and not report an error.
86  /// When MustCreateTM is used, we print an error if we are unable to load
87  /// the requested target.
88  void CreateTargetMachine(bool MustCreateTM);
89 
90  /// Add passes necessary to emit assembly or LLVM IR.
91  ///
92  /// \return True on success.
93  bool AddEmitPasses(legacy::PassManager &CodeGenPasses, BackendAction Action,
94  raw_pwrite_stream &OS);
95 
96 public:
97  EmitAssemblyHelper(DiagnosticsEngine &_Diags, const CodeGenOptions &CGOpts,
98  const clang::TargetOptions &TOpts,
99  const LangOptions &LOpts, Module *M)
100  : Diags(_Diags), CodeGenOpts(CGOpts), TargetOpts(TOpts), LangOpts(LOpts),
101  TheModule(M), CodeGenerationTime("Code Generation Time") {}
102 
103  ~EmitAssemblyHelper() {
104  if (CodeGenOpts.DisableFree)
105  BuryPointer(std::move(TM));
106  }
107 
108  std::unique_ptr<TargetMachine> TM;
109 
111  std::unique_ptr<raw_pwrite_stream> OS);
112 };
113 
114 // We need this wrapper to access LangOpts and CGOpts from extension functions
115 // that we add to the PassManagerBuilder.
116 class PassManagerBuilderWrapper : public PassManagerBuilder {
117 public:
118  PassManagerBuilderWrapper(const CodeGenOptions &CGOpts,
119  const LangOptions &LangOpts)
120  : PassManagerBuilder(), CGOpts(CGOpts), LangOpts(LangOpts) {}
121  const CodeGenOptions &getCGOpts() const { return CGOpts; }
122  const LangOptions &getLangOpts() const { return LangOpts; }
123 private:
124  const CodeGenOptions &CGOpts;
125  const LangOptions &LangOpts;
126 };
127 
128 }
129 
130 static void addObjCARCAPElimPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
131  if (Builder.OptLevel > 0)
132  PM.add(createObjCARCAPElimPass());
133 }
134 
135 static void addObjCARCExpandPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
136  if (Builder.OptLevel > 0)
137  PM.add(createObjCARCExpandPass());
138 }
139 
140 static void addObjCARCOptPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
141  if (Builder.OptLevel > 0)
142  PM.add(createObjCARCOptPass());
143 }
144 
145 static void addAddDiscriminatorsPass(const PassManagerBuilder &Builder,
146  legacy::PassManagerBase &PM) {
147  PM.add(createAddDiscriminatorsPass());
148 }
149 
151  const PassManagerBuilder &Builder, legacy::PassManagerBase &PM) {
152  // instcombine is needed before sample profile annotation because it converts
153  // certain function calls to be inlinable. simplifycfg and sroa are needed
154  // before instcombine for necessary preparation. E.g. load store is eliminated
155  // properly so that instcombine will not introduce unecessary liverange.
156  PM.add(createCFGSimplificationPass());
157  PM.add(createSROAPass());
158  PM.add(createInstructionCombiningPass());
159 }
160 
161 static void addBoundsCheckingPass(const PassManagerBuilder &Builder,
162  legacy::PassManagerBase &PM) {
163  PM.add(createBoundsCheckingPass());
164 }
165 
166 static void addSanitizerCoveragePass(const PassManagerBuilder &Builder,
167  legacy::PassManagerBase &PM) {
168  const PassManagerBuilderWrapper &BuilderWrapper =
169  static_cast<const PassManagerBuilderWrapper&>(Builder);
170  const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
171  SanitizerCoverageOptions Opts;
172  Opts.CoverageType =
173  static_cast<SanitizerCoverageOptions::Type>(CGOpts.SanitizeCoverageType);
174  Opts.IndirectCalls = CGOpts.SanitizeCoverageIndirectCalls;
175  Opts.TraceBB = CGOpts.SanitizeCoverageTraceBB;
176  Opts.TraceCmp = CGOpts.SanitizeCoverageTraceCmp;
177  Opts.Use8bitCounters = CGOpts.SanitizeCoverage8bitCounters;
178  Opts.TracePC = CGOpts.SanitizeCoverageTracePC;
179  PM.add(createSanitizerCoverageModulePass(Opts));
180 }
181 
182 static void addAddressSanitizerPasses(const PassManagerBuilder &Builder,
183  legacy::PassManagerBase &PM) {
184  const PassManagerBuilderWrapper &BuilderWrapper =
185  static_cast<const PassManagerBuilderWrapper&>(Builder);
186  const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
187  bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Address);
188  bool UseAfterScope = CGOpts.SanitizeAddressUseAfterScope;
189  PM.add(createAddressSanitizerFunctionPass(/*CompileKernel*/ false, Recover,
190  UseAfterScope));
191  PM.add(createAddressSanitizerModulePass(/*CompileKernel*/false, Recover));
192 }
193 
194 static void addKernelAddressSanitizerPasses(const PassManagerBuilder &Builder,
195  legacy::PassManagerBase &PM) {
196  PM.add(createAddressSanitizerFunctionPass(
197  /*CompileKernel*/ true,
198  /*Recover*/ true, /*UseAfterScope*/ false));
199  PM.add(createAddressSanitizerModulePass(/*CompileKernel*/true,
200  /*Recover*/true));
201 }
202 
203 static void addMemorySanitizerPass(const PassManagerBuilder &Builder,
204  legacy::PassManagerBase &PM) {
205  const PassManagerBuilderWrapper &BuilderWrapper =
206  static_cast<const PassManagerBuilderWrapper&>(Builder);
207  const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
208  PM.add(createMemorySanitizerPass(CGOpts.SanitizeMemoryTrackOrigins));
209 
210  // MemorySanitizer inserts complex instrumentation that mostly follows
211  // the logic of the original code, but operates on "shadow" values.
212  // It can benefit from re-running some general purpose optimization passes.
213  if (Builder.OptLevel > 0) {
214  PM.add(createEarlyCSEPass());
215  PM.add(createReassociatePass());
216  PM.add(createLICMPass());
217  PM.add(createGVNPass());
218  PM.add(createInstructionCombiningPass());
219  PM.add(createDeadStoreEliminationPass());
220  }
221 }
222 
223 static void addThreadSanitizerPass(const PassManagerBuilder &Builder,
224  legacy::PassManagerBase &PM) {
225  PM.add(createThreadSanitizerPass());
226 }
227 
228 static void addDataFlowSanitizerPass(const PassManagerBuilder &Builder,
229  legacy::PassManagerBase &PM) {
230  const PassManagerBuilderWrapper &BuilderWrapper =
231  static_cast<const PassManagerBuilderWrapper&>(Builder);
232  const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
233  PM.add(createDataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
234 }
235 
236 static void addEfficiencySanitizerPass(const PassManagerBuilder &Builder,
237  legacy::PassManagerBase &PM) {
238  const PassManagerBuilderWrapper &BuilderWrapper =
239  static_cast<const PassManagerBuilderWrapper&>(Builder);
240  const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
241  EfficiencySanitizerOptions Opts;
242  if (LangOpts.Sanitize.has(SanitizerKind::EfficiencyCacheFrag))
243  Opts.ToolType = EfficiencySanitizerOptions::ESAN_CacheFrag;
244  else if (LangOpts.Sanitize.has(SanitizerKind::EfficiencyWorkingSet))
245  Opts.ToolType = EfficiencySanitizerOptions::ESAN_WorkingSet;
246  PM.add(createEfficiencySanitizerPass(Opts));
247 }
248 
249 static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
250  const CodeGenOptions &CodeGenOpts) {
251  TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple);
252  if (!CodeGenOpts.SimplifyLibCalls)
253  TLII->disableAllFunctions();
254  else {
255  // Disable individual libc/libm calls in TargetLibraryInfo.
256  LibFunc::Func F;
257  for (auto &FuncName : CodeGenOpts.getNoBuiltinFuncs())
258  if (TLII->getLibFunc(FuncName, F))
259  TLII->setUnavailable(F);
260  }
261 
262  switch (CodeGenOpts.getVecLib()) {
264  TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::Accelerate);
265  break;
266  default:
267  break;
268  }
269  return TLII;
270 }
271 
272 static void addSymbolRewriterPass(const CodeGenOptions &Opts,
273  legacy::PassManager *MPM) {
274  llvm::SymbolRewriter::RewriteDescriptorList DL;
275 
276  llvm::SymbolRewriter::RewriteMapParser MapParser;
277  for (const auto &MapFile : Opts.RewriteMapFiles)
278  MapParser.parse(MapFile, &DL);
279 
280  MPM->add(createRewriteSymbolsPass(DL));
281 }
282 
283 void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
284  legacy::FunctionPassManager &FPM,
285  ModuleSummaryIndex *ModuleSummary) {
286  if (CodeGenOpts.DisableLLVMPasses)
287  return;
288 
289  unsigned OptLevel = CodeGenOpts.OptimizationLevel;
290  CodeGenOptions::InliningMethod Inlining = CodeGenOpts.getInlining();
291 
292  // Handle disabling of LLVM optimization, where we want to preserve the
293  // internal module before any optimization.
294  if (CodeGenOpts.DisableLLVMOpts) {
295  OptLevel = 0;
296  Inlining = CodeGenOpts.NoInlining;
297  }
298 
299  PassManagerBuilderWrapper PMBuilder(CodeGenOpts, LangOpts);
300 
301  // Figure out TargetLibraryInfo.
302  Triple TargetTriple(TheModule->getTargetTriple());
303  PMBuilder.LibraryInfo = createTLII(TargetTriple, CodeGenOpts);
304 
305  switch (Inlining) {
307  break;
310  PMBuilder.Inliner =
311  createFunctionInliningPass(OptLevel, CodeGenOpts.OptimizeSize);
312  break;
313  }
315  // Respect always_inline.
316  if (OptLevel == 0)
317  // Do not insert lifetime intrinsics at -O0.
318  PMBuilder.Inliner = createAlwaysInlinerPass(false);
319  else
320  PMBuilder.Inliner = createAlwaysInlinerPass();
321  break;
322  }
323 
324  PMBuilder.OptLevel = OptLevel;
325  PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
326  PMBuilder.BBVectorize = CodeGenOpts.VectorizeBB;
327  PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
328  PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
329 
330  PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
331  PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
332  PMBuilder.PrepareForThinLTO = CodeGenOpts.EmitSummaryIndex;
333  PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
334  PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
335 
336  // If we are performing a ThinLTO importing compile, invoke the LTO
337  // pipeline and pass down the in-memory module summary index.
338  if (ModuleSummary) {
339  PMBuilder.ModuleSummary = ModuleSummary;
340  PMBuilder.populateThinLTOPassManager(MPM);
341  return;
342  }
343 
344  // Add target-specific passes that need to run as early as possible.
345  if (TM)
346  PMBuilder.addExtension(
347  PassManagerBuilder::EP_EarlyAsPossible,
348  [&](const PassManagerBuilder &, legacy::PassManagerBase &PM) {
349  TM->addEarlyAsPossiblePasses(PM);
350  });
351 
352  PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
354 
355  // In ObjC ARC mode, add the main ARC optimization passes.
356  if (LangOpts.ObjCAutoRefCount) {
357  PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
359  PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
361  PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
363  }
364 
365  if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds)) {
366  PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
368  PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
370  }
371 
372  if (CodeGenOpts.SanitizeCoverageType ||
373  CodeGenOpts.SanitizeCoverageIndirectCalls ||
374  CodeGenOpts.SanitizeCoverageTraceCmp) {
375  PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
377  PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
379  }
380 
381  if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
382  PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
384  PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
386  }
387 
388  if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
389  PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
391  PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
393  }
394 
395  if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
396  PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
398  PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
400  }
401 
402  if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
403  PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
405  PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
407  }
408 
409  if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
410  PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
412  PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
414  }
415 
416  if (LangOpts.Sanitize.hasOneOf(SanitizerKind::Efficiency)) {
417  PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
419  PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
421  }
422 
423  // Set up the per-function pass manager.
424  if (CodeGenOpts.VerifyModule)
425  FPM.add(createVerifierPass());
426 
427  // Set up the per-module pass manager.
428  if (!CodeGenOpts.RewriteMapFiles.empty())
429  addSymbolRewriterPass(CodeGenOpts, &MPM);
430 
431  if (!CodeGenOpts.DisableGCov &&
432  (CodeGenOpts.EmitGcovArcs || CodeGenOpts.EmitGcovNotes)) {
433  // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
434  // LLVM's -default-gcov-version flag is set to something invalid.
435  GCOVOptions Options;
436  Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
437  Options.EmitData = CodeGenOpts.EmitGcovArcs;
438  memcpy(Options.Version, CodeGenOpts.CoverageVersion, 4);
439  Options.UseCfgChecksum = CodeGenOpts.CoverageExtraChecksum;
440  Options.NoRedZone = CodeGenOpts.DisableRedZone;
441  Options.FunctionNamesInData =
442  !CodeGenOpts.CoverageNoFunctionNamesInData;
443  Options.ExitBlockBeforeBody = CodeGenOpts.CoverageExitBlockBeforeBody;
444  MPM.add(createGCOVProfilerPass(Options));
445  if (CodeGenOpts.getDebugInfo() == codegenoptions::NoDebugInfo)
446  MPM.add(createStripSymbolsPass(true));
447  }
448 
449  if (CodeGenOpts.hasProfileClangInstr()) {
450  InstrProfOptions Options;
451  Options.NoRedZone = CodeGenOpts.DisableRedZone;
452  Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
453  MPM.add(createInstrProfilingLegacyPass(Options));
454  }
455  if (CodeGenOpts.hasProfileIRInstr()) {
456  if (!CodeGenOpts.InstrProfileOutput.empty())
457  PMBuilder.PGOInstrGen = CodeGenOpts.InstrProfileOutput;
458  else
459  PMBuilder.PGOInstrGen = "default.profraw";
460  }
461  if (CodeGenOpts.hasProfileIRUse())
462  PMBuilder.PGOInstrUse = CodeGenOpts.ProfileInstrumentUsePath;
463 
464  if (!CodeGenOpts.SampleProfileFile.empty()) {
465  MPM.add(createPruneEHPass());
466  MPM.add(createSampleProfileLoaderPass(CodeGenOpts.SampleProfileFile));
467  PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
469  }
470 
471  PMBuilder.populateFunctionPassManager(FPM);
472  PMBuilder.populateModulePassManager(MPM);
473 }
474 
475 void EmitAssemblyHelper::setCommandLineOpts() {
476  SmallVector<const char *, 16> BackendArgs;
477  BackendArgs.push_back("clang"); // Fake program name.
478  if (!CodeGenOpts.DebugPass.empty()) {
479  BackendArgs.push_back("-debug-pass");
480  BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
481  }
482  if (!CodeGenOpts.LimitFloatPrecision.empty()) {
483  BackendArgs.push_back("-limit-float-precision");
484  BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
485  }
486  for (const std::string &BackendOption : CodeGenOpts.BackendOptions)
487  BackendArgs.push_back(BackendOption.c_str());
488  BackendArgs.push_back(nullptr);
489  llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
490  BackendArgs.data());
491 }
492 
493 void EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
494  // Create the TargetMachine for generating code.
495  std::string Error;
496  std::string Triple = TheModule->getTargetTriple();
497  const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
498  if (!TheTarget) {
499  if (MustCreateTM)
500  Diags.Report(diag::err_fe_unable_to_create_target) << Error;
501  return;
502  }
503 
504  unsigned CodeModel =
505  llvm::StringSwitch<unsigned>(CodeGenOpts.CodeModel)
506  .Case("small", llvm::CodeModel::Small)
507  .Case("kernel", llvm::CodeModel::Kernel)
508  .Case("medium", llvm::CodeModel::Medium)
509  .Case("large", llvm::CodeModel::Large)
510  .Case("default", llvm::CodeModel::Default)
511  .Default(~0u);
512  assert(CodeModel != ~0u && "invalid code model!");
513  llvm::CodeModel::Model CM = static_cast<llvm::CodeModel::Model>(CodeModel);
514 
515  std::string FeaturesStr =
516  llvm::join(TargetOpts.Features.begin(), TargetOpts.Features.end(), ",");
517 
518  // Keep this synced with the equivalent code in tools/driver/cc1as_main.cpp.
520  if (CodeGenOpts.RelocationModel == "static") {
521  RM = llvm::Reloc::Static;
522  } else if (CodeGenOpts.RelocationModel == "pic") {
523  RM = llvm::Reloc::PIC_;
524  } else {
525  assert(CodeGenOpts.RelocationModel == "dynamic-no-pic" &&
526  "Invalid PIC model!");
527  RM = llvm::Reloc::DynamicNoPIC;
528  }
529 
530  CodeGenOpt::Level OptLevel = CodeGenOpt::Default;
531  switch (CodeGenOpts.OptimizationLevel) {
532  default: break;
533  case 0: OptLevel = CodeGenOpt::None; break;
534  case 3: OptLevel = CodeGenOpt::Aggressive; break;
535  }
536 
537  llvm::TargetOptions Options;
538 
539  if (!TargetOpts.Reciprocals.empty())
540  Options.Reciprocals = TargetRecip(TargetOpts.Reciprocals);
541 
542  Options.ThreadModel =
543  llvm::StringSwitch<llvm::ThreadModel::Model>(CodeGenOpts.ThreadModel)
544  .Case("posix", llvm::ThreadModel::POSIX)
545  .Case("single", llvm::ThreadModel::Single);
546 
547  // Set float ABI type.
548  assert((CodeGenOpts.FloatABI == "soft" || CodeGenOpts.FloatABI == "softfp" ||
549  CodeGenOpts.FloatABI == "hard" || CodeGenOpts.FloatABI.empty()) &&
550  "Invalid Floating Point ABI!");
551  Options.FloatABIType =
552  llvm::StringSwitch<llvm::FloatABI::ABIType>(CodeGenOpts.FloatABI)
553  .Case("soft", llvm::FloatABI::Soft)
554  .Case("softfp", llvm::FloatABI::Soft)
555  .Case("hard", llvm::FloatABI::Hard)
556  .Default(llvm::FloatABI::Default);
557 
558  // Set FP fusion mode.
559  switch (CodeGenOpts.getFPContractMode()) {
561  Options.AllowFPOpFusion = llvm::FPOpFusion::Strict;
562  break;
564  Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
565  break;
567  Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
568  break;
569  }
570 
571  Options.UseInitArray = CodeGenOpts.UseInitArray;
572  Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
573  Options.CompressDebugSections = CodeGenOpts.CompressDebugSections;
574  Options.RelaxELFRelocations = CodeGenOpts.RelaxELFRelocations;
575 
576  // Set EABI version.
577  Options.EABIVersion = llvm::StringSwitch<llvm::EABI>(TargetOpts.EABIVersion)
578  .Case("4", llvm::EABI::EABI4)
579  .Case("5", llvm::EABI::EABI5)
580  .Case("gnu", llvm::EABI::GNU)
581  .Default(llvm::EABI::Default);
582 
583  if (LangOpts.SjLjExceptions)
584  Options.ExceptionModel = llvm::ExceptionHandling::SjLj;
585 
586  Options.LessPreciseFPMADOption = CodeGenOpts.LessPreciseFPMAD;
587  Options.NoInfsFPMath = CodeGenOpts.NoInfsFPMath;
588  Options.NoNaNsFPMath = CodeGenOpts.NoNaNsFPMath;
589  Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
590  Options.UnsafeFPMath = CodeGenOpts.UnsafeFPMath;
591  Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
592  Options.FunctionSections = CodeGenOpts.FunctionSections;
593  Options.DataSections = CodeGenOpts.DataSections;
594  Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
595  Options.EmulatedTLS = CodeGenOpts.EmulatedTLS;
596  Options.DebuggerTuning = CodeGenOpts.getDebuggerTuning();
597 
598  Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
599  Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
600  Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
601  Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
602  Options.MCOptions.MCIncrementalLinkerCompatible =
603  CodeGenOpts.IncrementalLinkerCompatible;
604  Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
605  Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
606  Options.MCOptions.ABIName = TargetOpts.ABI;
607 
608  TM.reset(TheTarget->createTargetMachine(Triple, TargetOpts.CPU, FeaturesStr,
609  Options, RM, CM, OptLevel));
610 }
611 
612 bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
614  raw_pwrite_stream &OS) {
615  // Add LibraryInfo.
616  llvm::Triple TargetTriple(TheModule->getTargetTriple());
617  std::unique_ptr<TargetLibraryInfoImpl> TLII(
618  createTLII(TargetTriple, CodeGenOpts));
619  CodeGenPasses.add(new TargetLibraryInfoWrapperPass(*TLII));
620 
621  // Normal mode, emit a .s or .o file by running the code generator. Note,
622  // this also adds codegenerator level optimization passes.
623  TargetMachine::CodeGenFileType CGFT = TargetMachine::CGFT_AssemblyFile;
624  if (Action == Backend_EmitObj)
625  CGFT = TargetMachine::CGFT_ObjectFile;
626  else if (Action == Backend_EmitMCNull)
627  CGFT = TargetMachine::CGFT_Null;
628  else
629  assert(Action == Backend_EmitAssembly && "Invalid action!");
630 
631  // Add ObjC ARC final-cleanup optimizations. This is done as part of the
632  // "codegen" passes so that it isn't run multiple times when there is
633  // inlining happening.
634  if (CodeGenOpts.OptimizationLevel > 0)
635  CodeGenPasses.add(createObjCARCContractPass());
636 
637  if (TM->addPassesToEmitFile(CodeGenPasses, OS, CGFT,
638  /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
639  Diags.Report(diag::err_fe_unable_to_interface_with_target);
640  return false;
641  }
642 
643  return true;
644 }
645 
647  std::unique_ptr<raw_pwrite_stream> OS) {
648  TimeRegion Region(llvm::TimePassesIsEnabled ? &CodeGenerationTime : nullptr);
649 
650  setCommandLineOpts();
651 
652  bool UsesCodeGen = (Action != Backend_EmitNothing &&
653  Action != Backend_EmitBC &&
654  Action != Backend_EmitLL);
655  CreateTargetMachine(UsesCodeGen);
656 
657  if (UsesCodeGen && !TM)
658  return;
659  if (TM)
660  TheModule->setDataLayout(TM->createDataLayout());
661 
662  // If we are performing a ThinLTO importing compile, load the function
663  // index into memory and pass it into CreatePasses, which will add it
664  // to the PassManagerBuilder and invoke LTO passes.
665  std::unique_ptr<ModuleSummaryIndex> ModuleSummary;
666  if (!CodeGenOpts.ThinLTOIndexFile.empty()) {
667  ErrorOr<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
668  llvm::getModuleSummaryIndexForFile(
669  CodeGenOpts.ThinLTOIndexFile, [&](const DiagnosticInfo &DI) {
670  TheModule->getContext().diagnose(DI);
671  });
672  if (std::error_code EC = IndexOrErr.getError()) {
673  std::string Error = EC.message();
674  errs() << "Error loading index file '" << CodeGenOpts.ThinLTOIndexFile
675  << "': " << Error << "\n";
676  return;
677  }
678  ModuleSummary = std::move(IndexOrErr.get());
679  assert(ModuleSummary && "Expected non-empty module summary index");
680  }
681 
682  legacy::PassManager PerModulePasses;
683  PerModulePasses.add(
684  createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
685 
686  legacy::FunctionPassManager PerFunctionPasses(TheModule);
687  PerFunctionPasses.add(
688  createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
689 
690  CreatePasses(PerModulePasses, PerFunctionPasses, ModuleSummary.get());
691 
692  legacy::PassManager CodeGenPasses;
693  CodeGenPasses.add(
694  createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
695 
696  switch (Action) {
697  case Backend_EmitNothing:
698  break;
699 
700  case Backend_EmitBC:
701  PerModulePasses.add(createBitcodeWriterPass(
702  *OS, CodeGenOpts.EmitLLVMUseLists, CodeGenOpts.EmitSummaryIndex,
703  CodeGenOpts.EmitSummaryIndex));
704  break;
705 
706  case Backend_EmitLL:
707  PerModulePasses.add(
708  createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
709  break;
710 
711  default:
712  if (!AddEmitPasses(CodeGenPasses, Action, *OS))
713  return;
714  }
715 
716  // Before executing passes, print the final values of the LLVM options.
717  cl::PrintOptionValues();
718 
719  // Run passes. For now we do all passes at once, but eventually we
720  // would like to have the option of streaming code generation.
721 
722  {
723  PrettyStackTraceString CrashInfo("Per-function optimization");
724 
725  PerFunctionPasses.doInitialization();
726  for (Function &F : *TheModule)
727  if (!F.isDeclaration())
728  PerFunctionPasses.run(F);
729  PerFunctionPasses.doFinalization();
730  }
731 
732  {
733  PrettyStackTraceString CrashInfo("Per-module optimization passes");
734  PerModulePasses.run(*TheModule);
735  }
736 
737  {
738  PrettyStackTraceString CrashInfo("Code generation");
739  CodeGenPasses.run(*TheModule);
740  }
741 }
742 
744  const CodeGenOptions &CGOpts,
745  const clang::TargetOptions &TOpts,
746  const LangOptions &LOpts, const llvm::DataLayout &TDesc,
747  Module *M, BackendAction Action,
748  std::unique_ptr<raw_pwrite_stream> OS) {
749  EmitAssemblyHelper AsmHelper(Diags, CGOpts, TOpts, LOpts, M);
750 
751  AsmHelper.EmitAssembly(Action, std::move(OS));
752 
753  // Verify clang's TargetInfo DataLayout against the LLVM TargetMachine's
754  // DataLayout.
755  if (AsmHelper.TM) {
756  std::string DLDesc = M->getDataLayout().getStringRepresentation();
757  if (DLDesc != TDesc.getStringRepresentation()) {
758  unsigned DiagID = Diags.getCustomDiagID(
759  DiagnosticsEngine::Error, "backend data layout '%0' does not match "
760  "expected target description '%1'");
761  Diags.Report(DiagID) << DLDesc << TDesc.getStringRepresentation();
762  }
763  }
764 }
765 
766 static const char* getSectionNameForBitcode(const Triple &T) {
767  switch (T.getObjectFormat()) {
768  case Triple::MachO:
769  return "__LLVM,__bitcode";
770  case Triple::COFF:
771  case Triple::ELF:
772  case Triple::UnknownObjectFormat:
773  return ".llvmbc";
774  }
775  llvm_unreachable("Unimplemented ObjectFormatType");
776 }
777 
778 static const char* getSectionNameForCommandline(const Triple &T) {
779  switch (T.getObjectFormat()) {
780  case Triple::MachO:
781  return "__LLVM,__cmdline";
782  case Triple::COFF:
783  case Triple::ELF:
784  case Triple::UnknownObjectFormat:
785  return ".llvmcmd";
786  }
787  llvm_unreachable("Unimplemented ObjectFormatType");
788 }
789 
790 // With -fembed-bitcode, save a copy of the llvm IR as data in the
791 // __LLVM,__bitcode section.
792 void clang::EmbedBitcode(llvm::Module *M, const CodeGenOptions &CGOpts,
793  llvm::MemoryBufferRef Buf) {
794  if (CGOpts.getEmbedBitcode() == CodeGenOptions::Embed_Off)
795  return;
796 
797  // Save llvm.compiler.used and remote it.
798  SmallVector<Constant*, 2> UsedArray;
799  SmallSet<GlobalValue*, 4> UsedGlobals;
800  Type *UsedElementType = Type::getInt8Ty(M->getContext())->getPointerTo(0);
801  GlobalVariable *Used = collectUsedGlobalVariables(*M, UsedGlobals, true);
802  for (auto *GV : UsedGlobals) {
803  if (GV->getName() != "llvm.embedded.module" &&
804  GV->getName() != "llvm.cmdline")
805  UsedArray.push_back(
806  ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
807  }
808  if (Used)
809  Used->eraseFromParent();
810 
811  // Embed the bitcode for the llvm module.
812  std::string Data;
813  ArrayRef<uint8_t> ModuleData;
814  Triple T(M->getTargetTriple());
815  // Create a constant that contains the bitcode.
816  // In case of embedding a marker, ignore the input Buf and use the empty
817  // ArrayRef. It is also legal to create a bitcode marker even Buf is empty.
818  if (CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Marker) {
819  if (!isBitcode((const unsigned char *)Buf.getBufferStart(),
820  (const unsigned char *)Buf.getBufferEnd())) {
821  // If the input is LLVM Assembly, bitcode is produced by serializing
822  // the module. Use-lists order need to be perserved in this case.
823  llvm::raw_string_ostream OS(Data);
824  llvm::WriteBitcodeToFile(M, OS, /* ShouldPreserveUseListOrder */ true);
825  ModuleData =
826  ArrayRef<uint8_t>((const uint8_t *)OS.str().data(), OS.str().size());
827  } else
828  // If the input is LLVM bitcode, write the input byte stream directly.
829  ModuleData = ArrayRef<uint8_t>((const uint8_t *)Buf.getBufferStart(),
830  Buf.getBufferSize());
831  }
832  llvm::Constant *ModuleConstant =
833  llvm::ConstantDataArray::get(M->getContext(), ModuleData);
834  llvm::GlobalVariable *GV = new llvm::GlobalVariable(
835  *M, ModuleConstant->getType(), true, llvm::GlobalValue::PrivateLinkage,
836  ModuleConstant);
837  GV->setSection(getSectionNameForBitcode(T));
838  UsedArray.push_back(
839  ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
840  if (llvm::GlobalVariable *Old =
841  M->getGlobalVariable("llvm.embedded.module", true)) {
842  assert(Old->hasOneUse() &&
843  "llvm.embedded.module can only be used once in llvm.compiler.used");
844  GV->takeName(Old);
845  Old->eraseFromParent();
846  } else {
847  GV->setName("llvm.embedded.module");
848  }
849 
850  // Skip if only bitcode needs to be embedded.
851  if (CGOpts.getEmbedBitcode() != CodeGenOptions::Embed_Bitcode) {
852  // Embed command-line options.
853  ArrayRef<uint8_t> CmdData(const_cast<uint8_t *>(CGOpts.CmdArgs.data()),
854  CGOpts.CmdArgs.size());
855  llvm::Constant *CmdConstant =
856  llvm::ConstantDataArray::get(M->getContext(), CmdData);
857  GV = new llvm::GlobalVariable(*M, CmdConstant->getType(), true,
858  llvm::GlobalValue::PrivateLinkage,
859  CmdConstant);
860  GV->setSection(getSectionNameForCommandline(T));
861  UsedArray.push_back(
862  ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, UsedElementType));
863  if (llvm::GlobalVariable *Old =
864  M->getGlobalVariable("llvm.cmdline", true)) {
865  assert(Old->hasOneUse() &&
866  "llvm.cmdline can only be used once in llvm.compiler.used");
867  GV->takeName(Old);
868  Old->eraseFromParent();
869  } else {
870  GV->setName("llvm.cmdline");
871  }
872  }
873 
874  if (UsedArray.empty())
875  return;
876 
877  // Recreate llvm.compiler.used.
878  ArrayType *ATy = ArrayType::get(UsedElementType, UsedArray.size());
879  auto *NewUsed = new GlobalVariable(
880  *M, ATy, false, llvm::GlobalValue::AppendingLinkage,
881  llvm::ConstantArray::get(ATy, UsedArray), "llvm.compiler.used");
882  NewUsed->setSection("llvm.metadata");
883 }
static void addObjCARCExpandPass(const PassManagerBuilder &Builder, PassManagerBase &PM)
Emit human-readable LLVM assembly.
Definition: BackendUtil.h:31
Run CodeGen, but don't emit anything.
Definition: BackendUtil.h:33
SanitizerSet Sanitize
Set of enabled sanitizers.
Definition: LangOptions.h:87
The base class of the type hierarchy.
Definition: Type.h:1281
DiagnosticBuilder Report(SourceLocation Loc, unsigned DiagID)
Issue the message to the client.
Definition: Diagnostic.h:1124
Represents an array type, per C99 6.7.5.2 - Array Declarators.
Definition: Type.h:2456
static void addAddressSanitizerPasses(const PassManagerBuilder &Builder, legacy::PassManagerBase &PM)
std::vector< std::string > RewriteMapFiles
Set of files definining the rules for the symbol rewriting.
Don't emit anything (benchmarking mode)
Definition: BackendUtil.h:32
Options for controlling the target.
Definition: TargetOptions.h:25
SanitizerSet SanitizeRecover
Set of sanitizer checks that are non-fatal (i.e.
Emit LLVM bitcode files.
Definition: BackendUtil.h:30
FrontendAction * Action
Definition: Tooling.cpp:201
std::vector< uint8_t > CmdArgs
List of backend command-line options for -fembed-bitcode.
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:48
Describes a module or submodule.
Definition: Basic/Module.h:47
BackendAction
Definition: BackendUtil.h:28
Concrete class used by the front-end to report problems and issues.
Definition: Diagnostic.h:135
static void addThreadSanitizerPass(const PassManagerBuilder &Builder, legacy::PassManagerBase &PM)
static void addSanitizerCoveragePass(const PassManagerBuilder &Builder, legacy::PassManagerBase &PM)
Defines the clang::LangOptions interface.
static void addObjCARCAPElimPass(const PassManagerBuilder &Builder, PassManagerBase &PM)
static TargetLibraryInfoImpl * createTLII(llvm::Triple &TargetTriple, const CodeGenOptions &CodeGenOpts)
Emit native object files.
Definition: BackendUtil.h:34
Emit native assembly files.
Definition: BackendUtil.h:29
const MatchFinder::MatchFinderOptions & Options
static void addKernelAddressSanitizerPasses(const PassManagerBuilder &Builder, legacy::PassManagerBase &PM)
static void addSymbolRewriterPass(const CodeGenOptions &Opts, legacy::PassManager *MPM)
const std::vector< std::string > & getNoBuiltinFuncs() const
static void addDataFlowSanitizerPass(const PassManagerBuilder &Builder, legacy::PassManagerBase &PM)
Defines the clang::TargetOptions class.
unsigned getCustomDiagID(Level L, const char(&FormatString)[N])
Return an ID for a diagnostic with the specified format string and level.
Definition: Diagnostic.h:609
if(T->getSizeExpr()) TRY_TO(TraverseStmt(T-> getSizeExpr()))
void EmbedBitcode(llvm::Module *M, const CodeGenOptions &CGOpts, llvm::MemoryBufferRef Buf)
Defines the Diagnostic-related interfaces.
static const char * getSectionNameForBitcode(const Triple &T)
static const char * getSectionNameForCommandline(const Triple &T)
void BuryPointer(const void *Ptr)
static void addBoundsCheckingPass(const PassManagerBuilder &Builder, legacy::PassManagerBase &PM)
bool has(SanitizerMask K) const
Check if a certain (single) sanitizer is enabled.
Definition: Sanitizers.h:50
static void addEfficiencySanitizerPass(const PassManagerBuilder &Builder, legacy::PassManagerBase &PM)
CodeGenOptions - Track various options which control how the code is optimized and passed to the back...
static void addObjCARCOptPass(const PassManagerBuilder &Builder, PassManagerBase &PM)
BoundNodesTreeBuilder *const Builder
void EmitBackendOutput(DiagnosticsEngine &Diags, const CodeGenOptions &CGOpts, const TargetOptions &TOpts, const LangOptions &LOpts, const llvm::DataLayout &TDesc, llvm::Module *M, BackendAction Action, std::unique_ptr< raw_pwrite_stream > OS)
static void addCleanupPassesForSampleProfiler(const PassManagerBuilder &Builder, legacy::PassManagerBase &PM)
static void addAddDiscriminatorsPass(const PassManagerBuilder &Builder, legacy::PassManagerBase &PM)
std::vector< std::string > SanitizerBlacklistFiles
Paths to blacklist files specifying which objects (files, functions, variables) should not be instrum...
Definition: LangOptions.h:91
static void addMemorySanitizerPass(const PassManagerBuilder &Builder, legacy::PassManagerBase &PM)