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
10#include "clang/CodeGen/BackendUtil.h"
11#include "clang/Basic/Diagnostic.h"
12#include "clang/Basic/LangOptions.h"
13#include "clang/Basic/TargetOptions.h"
14#include "clang/Frontend/CodeGenOptions.h"
15#include "clang/Frontend/FrontendDiagnostic.h"
16#include "clang/Frontend/Utils.h"
17#include "llvm/ADT/StringSwitch.h"
18#include "llvm/Analysis/TargetLibraryInfo.h"
19#include "llvm/Analysis/TargetTransformInfo.h"
20#include "llvm/Bitcode/BitcodeWriterPass.h"
21#include "llvm/CodeGen/RegAllocRegistry.h"
22#include "llvm/CodeGen/SchedulerRegistry.h"
23#include "llvm/IR/DataLayout.h"
24#include "llvm/IR/IRPrintingPasses.h"
25#include "llvm/IR/LegacyPassManager.h"
26#include "llvm/IR/Module.h"
27#include "llvm/IR/Verifier.h"
28#include "llvm/MC/SubtargetFeature.h"
29#include "llvm/Support/CommandLine.h"
30#include "llvm/Support/PrettyStackTrace.h"
31#include "llvm/Support/TargetRegistry.h"
32#include "llvm/Support/Timer.h"
33#include "llvm/Support/raw_ostream.h"
34#include "llvm/Target/TargetMachine.h"
35#include "llvm/Target/TargetOptions.h"
36#include "llvm/Target/TargetSubtargetInfo.h"
37#include "llvm/Transforms/IPO.h"
38#include "llvm/Transforms/IPO/PassManagerBuilder.h"
39#include "llvm/Transforms/Instrumentation.h"
40#include "llvm/Transforms/ObjCARC.h"
41#include "llvm/Transforms/Scalar.h"
42#include "llvm/Transforms/Utils/SymbolRewriter.h"
43#include <memory>
44using namespace clang;
45using namespace llvm;
46
47namespace {
48
49class EmitAssemblyHelper {
50  DiagnosticsEngine &Diags;
51  const CodeGenOptions &CodeGenOpts;
52  const clang::TargetOptions &TargetOpts;
53  const LangOptions &LangOpts;
54  Module *TheModule;
55
56  Timer CodeGenerationTime;
57
58  mutable legacy::PassManager *CodeGenPasses;
59  mutable legacy::PassManager *PerModulePasses;
60  mutable legacy::FunctionPassManager *PerFunctionPasses;
61
62private:
63  TargetIRAnalysis getTargetIRAnalysis() const {
64    if (TM)
65      return TM->getTargetIRAnalysis();
66
67    return TargetIRAnalysis();
68  }
69
70  legacy::PassManager *getCodeGenPasses() const {
71    if (!CodeGenPasses) {
72      CodeGenPasses = new legacy::PassManager();
73      CodeGenPasses->add(
74          createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
75    }
76    return CodeGenPasses;
77  }
78
79  legacy::PassManager *getPerModulePasses() const {
80    if (!PerModulePasses) {
81      PerModulePasses = new legacy::PassManager();
82      PerModulePasses->add(
83          createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
84    }
85    return PerModulePasses;
86  }
87
88  legacy::FunctionPassManager *getPerFunctionPasses() const {
89    if (!PerFunctionPasses) {
90      PerFunctionPasses = new legacy::FunctionPassManager(TheModule);
91      PerFunctionPasses->add(
92          createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
93    }
94    return PerFunctionPasses;
95  }
96
97  void CreatePasses();
98
99  /// Generates the TargetMachine.
100  /// Returns Null if it is unable to create the target machine.
101  /// Some of our clang tests specify triples which are not built
102  /// into clang. This is okay because these tests check the generated
103  /// IR, and they require DataLayout which depends on the triple.
104  /// In this case, we allow this method to fail and not report an error.
105  /// When MustCreateTM is used, we print an error if we are unable to load
106  /// the requested target.
107  TargetMachine *CreateTargetMachine(bool MustCreateTM);
108
109  /// Add passes necessary to emit assembly or LLVM IR.
110  ///
111  /// \return True on success.
112  bool AddEmitPasses(BackendAction Action, raw_pwrite_stream &OS);
113
114public:
115  EmitAssemblyHelper(DiagnosticsEngine &_Diags,
116                     const CodeGenOptions &CGOpts,
117                     const clang::TargetOptions &TOpts,
118                     const LangOptions &LOpts,
119                     Module *M)
120    : Diags(_Diags), CodeGenOpts(CGOpts), TargetOpts(TOpts), LangOpts(LOpts),
121      TheModule(M), CodeGenerationTime("Code Generation Time"),
122      CodeGenPasses(nullptr), PerModulePasses(nullptr),
123      PerFunctionPasses(nullptr) {}
124
125  ~EmitAssemblyHelper() {
126    delete CodeGenPasses;
127    delete PerModulePasses;
128    delete PerFunctionPasses;
129    if (CodeGenOpts.DisableFree)
130      BuryPointer(std::move(TM));
131  }
132
133  std::unique_ptr<TargetMachine> TM;
134
135  void EmitAssembly(BackendAction Action, raw_pwrite_stream *OS);
136};
137
138// We need this wrapper to access LangOpts and CGOpts from extension functions
139// that we add to the PassManagerBuilder.
140class PassManagerBuilderWrapper : public PassManagerBuilder {
141public:
142  PassManagerBuilderWrapper(const CodeGenOptions &CGOpts,
143                            const LangOptions &LangOpts)
144      : PassManagerBuilder(), CGOpts(CGOpts), LangOpts(LangOpts) {}
145  const CodeGenOptions &getCGOpts() const { return CGOpts; }
146  const LangOptions &getLangOpts() const { return LangOpts; }
147private:
148  const CodeGenOptions &CGOpts;
149  const LangOptions &LangOpts;
150};
151
152}
153
154static void addObjCARCAPElimPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
155  if (Builder.OptLevel > 0)
156    PM.add(createObjCARCAPElimPass());
157}
158
159static void addObjCARCExpandPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
160  if (Builder.OptLevel > 0)
161    PM.add(createObjCARCExpandPass());
162}
163
164static void addObjCARCOptPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
165  if (Builder.OptLevel > 0)
166    PM.add(createObjCARCOptPass());
167}
168
169static void addSampleProfileLoaderPass(const PassManagerBuilder &Builder,
170                                       legacy::PassManagerBase &PM) {
171  const PassManagerBuilderWrapper &BuilderWrapper =
172      static_cast<const PassManagerBuilderWrapper &>(Builder);
173  const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
174  PM.add(createSampleProfileLoaderPass(CGOpts.SampleProfileFile));
175}
176
177static void addAddDiscriminatorsPass(const PassManagerBuilder &Builder,
178                                     legacy::PassManagerBase &PM) {
179  PM.add(createAddDiscriminatorsPass());
180}
181
182static void addBoundsCheckingPass(const PassManagerBuilder &Builder,
183                                    legacy::PassManagerBase &PM) {
184  PM.add(createBoundsCheckingPass());
185}
186
187static void addSanitizerCoveragePass(const PassManagerBuilder &Builder,
188                                     legacy::PassManagerBase &PM) {
189  const PassManagerBuilderWrapper &BuilderWrapper =
190      static_cast<const PassManagerBuilderWrapper&>(Builder);
191  const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
192  PM.add(createSanitizerCoverageModulePass(CGOpts.SanitizeCoverage));
193}
194
195static void addAddressSanitizerPasses(const PassManagerBuilder &Builder,
196                                      legacy::PassManagerBase &PM) {
197  PM.add(createAddressSanitizerFunctionPass());
198  PM.add(createAddressSanitizerModulePass());
199}
200
201static void addMemorySanitizerPass(const PassManagerBuilder &Builder,
202                                   legacy::PassManagerBase &PM) {
203  const PassManagerBuilderWrapper &BuilderWrapper =
204      static_cast<const PassManagerBuilderWrapper&>(Builder);
205  const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
206  PM.add(createMemorySanitizerPass(CGOpts.SanitizeMemoryTrackOrigins));
207
208  // MemorySanitizer inserts complex instrumentation that mostly follows
209  // the logic of the original code, but operates on "shadow" values.
210  // It can benefit from re-running some general purpose optimization passes.
211  if (Builder.OptLevel > 0) {
212    PM.add(createEarlyCSEPass());
213    PM.add(createReassociatePass());
214    PM.add(createLICMPass());
215    PM.add(createGVNPass());
216    PM.add(createInstructionCombiningPass());
217    PM.add(createDeadStoreEliminationPass());
218  }
219}
220
221static void addThreadSanitizerPass(const PassManagerBuilder &Builder,
222                                   legacy::PassManagerBase &PM) {
223  PM.add(createThreadSanitizerPass());
224}
225
226static void addDataFlowSanitizerPass(const PassManagerBuilder &Builder,
227                                     legacy::PassManagerBase &PM) {
228  const PassManagerBuilderWrapper &BuilderWrapper =
229      static_cast<const PassManagerBuilderWrapper&>(Builder);
230  const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
231  PM.add(createDataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
232}
233
234static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
235                                         const CodeGenOptions &CodeGenOpts) {
236  TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple);
237  if (!CodeGenOpts.SimplifyLibCalls)
238    TLII->disableAllFunctions();
239
240  switch (CodeGenOpts.getVecLib()) {
241  case CodeGenOptions::Accelerate:
242    TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::Accelerate);
243    break;
244  default:
245    break;
246  }
247  return TLII;
248}
249
250static void addSymbolRewriterPass(const CodeGenOptions &Opts,
251                                  legacy::PassManager *MPM) {
252  llvm::SymbolRewriter::RewriteDescriptorList DL;
253
254  llvm::SymbolRewriter::RewriteMapParser MapParser;
255  for (const auto &MapFile : Opts.RewriteMapFiles)
256    MapParser.parse(MapFile, &DL);
257
258  MPM->add(createRewriteSymbolsPass(DL));
259}
260
261void EmitAssemblyHelper::CreatePasses() {
262  unsigned OptLevel = CodeGenOpts.OptimizationLevel;
263  CodeGenOptions::InliningMethod Inlining = CodeGenOpts.getInlining();
264
265  // Handle disabling of LLVM optimization, where we want to preserve the
266  // internal module before any optimization.
267  if (CodeGenOpts.DisableLLVMOpts) {
268    OptLevel = 0;
269    Inlining = CodeGenOpts.NoInlining;
270  }
271
272  PassManagerBuilderWrapper PMBuilder(CodeGenOpts, LangOpts);
273  PMBuilder.OptLevel = OptLevel;
274  PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
275  PMBuilder.BBVectorize = CodeGenOpts.VectorizeBB;
276  PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
277  PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
278
279  PMBuilder.DisableTailCalls = CodeGenOpts.DisableTailCalls;
280  PMBuilder.DisableUnitAtATime = !CodeGenOpts.UnitAtATime;
281  PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
282  PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
283  PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
284
285  PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
286                         addAddDiscriminatorsPass);
287
288  if (!CodeGenOpts.SampleProfileFile.empty())
289    PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
290                           addSampleProfileLoaderPass);
291
292  // In ObjC ARC mode, add the main ARC optimization passes.
293  if (LangOpts.ObjCAutoRefCount) {
294    PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
295                           addObjCARCExpandPass);
296    PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
297                           addObjCARCAPElimPass);
298    PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
299                           addObjCARCOptPass);
300  }
301
302  if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds)) {
303    PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
304                           addBoundsCheckingPass);
305    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
306                           addBoundsCheckingPass);
307  }
308
309  if (CodeGenOpts.SanitizeCoverage) {
310    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
311                           addSanitizerCoveragePass);
312    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
313                           addSanitizerCoveragePass);
314  }
315
316  if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
317    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
318                           addAddressSanitizerPasses);
319    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
320                           addAddressSanitizerPasses);
321  }
322
323  if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
324    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
325                           addMemorySanitizerPass);
326    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
327                           addMemorySanitizerPass);
328  }
329
330  if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
331    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
332                           addThreadSanitizerPass);
333    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
334                           addThreadSanitizerPass);
335  }
336
337  if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
338    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
339                           addDataFlowSanitizerPass);
340    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
341                           addDataFlowSanitizerPass);
342  }
343
344  // Figure out TargetLibraryInfo.
345  Triple TargetTriple(TheModule->getTargetTriple());
346  PMBuilder.LibraryInfo = createTLII(TargetTriple, CodeGenOpts);
347
348  switch (Inlining) {
349  case CodeGenOptions::NoInlining: break;
350  case CodeGenOptions::NormalInlining: {
351    PMBuilder.Inliner =
352        createFunctionInliningPass(OptLevel, CodeGenOpts.OptimizeSize);
353    break;
354  }
355  case CodeGenOptions::OnlyAlwaysInlining:
356    // Respect always_inline.
357    if (OptLevel == 0)
358      // Do not insert lifetime intrinsics at -O0.
359      PMBuilder.Inliner = createAlwaysInlinerPass(false);
360    else
361      PMBuilder.Inliner = createAlwaysInlinerPass();
362    break;
363  }
364
365  // Set up the per-function pass manager.
366  legacy::FunctionPassManager *FPM = getPerFunctionPasses();
367  if (CodeGenOpts.VerifyModule)
368    FPM->add(createVerifierPass());
369  PMBuilder.populateFunctionPassManager(*FPM);
370
371  // Set up the per-module pass manager.
372  legacy::PassManager *MPM = getPerModulePasses();
373  if (!CodeGenOpts.RewriteMapFiles.empty())
374    addSymbolRewriterPass(CodeGenOpts, MPM);
375
376  if (!CodeGenOpts.DisableGCov &&
377      (CodeGenOpts.EmitGcovArcs || CodeGenOpts.EmitGcovNotes)) {
378    // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
379    // LLVM's -default-gcov-version flag is set to something invalid.
380    GCOVOptions Options;
381    Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
382    Options.EmitData = CodeGenOpts.EmitGcovArcs;
383    memcpy(Options.Version, CodeGenOpts.CoverageVersion, 4);
384    Options.UseCfgChecksum = CodeGenOpts.CoverageExtraChecksum;
385    Options.NoRedZone = CodeGenOpts.DisableRedZone;
386    Options.FunctionNamesInData =
387        !CodeGenOpts.CoverageNoFunctionNamesInData;
388    Options.ExitBlockBeforeBody = CodeGenOpts.CoverageExitBlockBeforeBody;
389    MPM->add(createGCOVProfilerPass(Options));
390    if (CodeGenOpts.getDebugInfo() == CodeGenOptions::NoDebugInfo)
391      MPM->add(createStripSymbolsPass(true));
392  }
393
394  if (CodeGenOpts.ProfileInstrGenerate) {
395    InstrProfOptions Options;
396    Options.NoRedZone = CodeGenOpts.DisableRedZone;
397    MPM->add(createInstrProfilingPass(Options));
398  }
399
400  PMBuilder.populateModulePassManager(*MPM);
401}
402
403TargetMachine *EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
404  // Create the TargetMachine for generating code.
405  std::string Error;
406  std::string Triple = TheModule->getTargetTriple();
407  const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
408  if (!TheTarget) {
409    if (MustCreateTM)
410      Diags.Report(diag::err_fe_unable_to_create_target) << Error;
411    return nullptr;
412  }
413
414  unsigned CodeModel =
415    llvm::StringSwitch<unsigned>(CodeGenOpts.CodeModel)
416      .Case("small", llvm::CodeModel::Small)
417      .Case("kernel", llvm::CodeModel::Kernel)
418      .Case("medium", llvm::CodeModel::Medium)
419      .Case("large", llvm::CodeModel::Large)
420      .Case("default", llvm::CodeModel::Default)
421      .Default(~0u);
422  assert(CodeModel != ~0u && "invalid code model!");
423  llvm::CodeModel::Model CM = static_cast<llvm::CodeModel::Model>(CodeModel);
424
425  SmallVector<const char *, 16> BackendArgs;
426  BackendArgs.push_back("clang"); // Fake program name.
427  if (!CodeGenOpts.DebugPass.empty()) {
428    BackendArgs.push_back("-debug-pass");
429    BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
430  }
431  if (!CodeGenOpts.LimitFloatPrecision.empty()) {
432    BackendArgs.push_back("-limit-float-precision");
433    BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
434  }
435  if (llvm::TimePassesIsEnabled)
436    BackendArgs.push_back("-time-passes");
437  for (unsigned i = 0, e = CodeGenOpts.BackendOptions.size(); i != e; ++i)
438    BackendArgs.push_back(CodeGenOpts.BackendOptions[i].c_str());
439  BackendArgs.push_back(nullptr);
440  llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
441                                    BackendArgs.data());
442
443  std::string FeaturesStr;
444  if (!TargetOpts.Features.empty()) {
445    SubtargetFeatures Features;
446    for (std::vector<std::string>::const_iterator
447           it = TargetOpts.Features.begin(),
448           ie = TargetOpts.Features.end(); it != ie; ++it)
449      Features.AddFeature(*it);
450    FeaturesStr = Features.getString();
451  }
452
453  llvm::Reloc::Model RM = llvm::Reloc::Default;
454  if (CodeGenOpts.RelocationModel == "static") {
455    RM = llvm::Reloc::Static;
456  } else if (CodeGenOpts.RelocationModel == "pic") {
457    RM = llvm::Reloc::PIC_;
458  } else {
459    assert(CodeGenOpts.RelocationModel == "dynamic-no-pic" &&
460           "Invalid PIC model!");
461    RM = llvm::Reloc::DynamicNoPIC;
462  }
463
464  CodeGenOpt::Level OptLevel = CodeGenOpt::Default;
465  switch (CodeGenOpts.OptimizationLevel) {
466  default: break;
467  case 0: OptLevel = CodeGenOpt::None; break;
468  case 3: OptLevel = CodeGenOpt::Aggressive; break;
469  }
470
471  llvm::TargetOptions Options;
472
473  Options.ThreadModel =
474    llvm::StringSwitch<llvm::ThreadModel::Model>(CodeGenOpts.ThreadModel)
475      .Case("posix", llvm::ThreadModel::POSIX)
476      .Case("single", llvm::ThreadModel::Single);
477
478  if (CodeGenOpts.DisableIntegratedAS)
479    Options.DisableIntegratedAS = true;
480
481  if (CodeGenOpts.CompressDebugSections)
482    Options.CompressDebugSections = true;
483
484  // Set frame pointer elimination mode.
485  if (!CodeGenOpts.DisableFPElim) {
486    Options.NoFramePointerElim = false;
487  } else if (CodeGenOpts.OmitLeafFramePointer) {
488    Options.NoFramePointerElim = false;
489  } else {
490    Options.NoFramePointerElim = true;
491  }
492
493  if (CodeGenOpts.UseInitArray)
494    Options.UseInitArray = true;
495
496  // Set float ABI type.
497  if (CodeGenOpts.FloatABI == "soft" || CodeGenOpts.FloatABI == "softfp")
498    Options.FloatABIType = llvm::FloatABI::Soft;
499  else if (CodeGenOpts.FloatABI == "hard")
500    Options.FloatABIType = llvm::FloatABI::Hard;
501  else {
502    assert(CodeGenOpts.FloatABI.empty() && "Invalid float abi!");
503    Options.FloatABIType = llvm::FloatABI::Default;
504  }
505
506  // Set FP fusion mode.
507  switch (CodeGenOpts.getFPContractMode()) {
508  case CodeGenOptions::FPC_Off:
509    Options.AllowFPOpFusion = llvm::FPOpFusion::Strict;
510    break;
511  case CodeGenOptions::FPC_On:
512    Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
513    break;
514  case CodeGenOptions::FPC_Fast:
515    Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
516    break;
517  }
518
519  Options.LessPreciseFPMADOption = CodeGenOpts.LessPreciseFPMAD;
520  Options.NoInfsFPMath = CodeGenOpts.NoInfsFPMath;
521  Options.NoNaNsFPMath = CodeGenOpts.NoNaNsFPMath;
522  Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
523  Options.UnsafeFPMath = CodeGenOpts.UnsafeFPMath;
524  Options.UseSoftFloat = CodeGenOpts.SoftFloat;
525  Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
526  Options.DisableTailCalls = CodeGenOpts.DisableTailCalls;
527  Options.TrapFuncName = CodeGenOpts.TrapFuncName;
528  Options.PositionIndependentExecutable = LangOpts.PIELevel != 0;
529  Options.FunctionSections = CodeGenOpts.FunctionSections;
530  Options.DataSections = CodeGenOpts.DataSections;
531  Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
532
533  Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
534  Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
535  Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
536  Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
537  Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
538  Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
539  Options.MCOptions.ABIName = TargetOpts.ABI;
540
541  TargetMachine *TM = TheTarget->createTargetMachine(Triple, TargetOpts.CPU,
542                                                     FeaturesStr, Options,
543                                                     RM, CM, OptLevel);
544
545  return TM;
546}
547
548bool EmitAssemblyHelper::AddEmitPasses(BackendAction Action,
549                                       raw_pwrite_stream &OS) {
550
551  // Create the code generator passes.
552  legacy::PassManager *PM = getCodeGenPasses();
553
554  // Add LibraryInfo.
555  llvm::Triple TargetTriple(TheModule->getTargetTriple());
556  std::unique_ptr<TargetLibraryInfoImpl> TLII(
557      createTLII(TargetTriple, CodeGenOpts));
558  PM->add(new TargetLibraryInfoWrapperPass(*TLII));
559
560  // Normal mode, emit a .s or .o file by running the code generator. Note,
561  // this also adds codegenerator level optimization passes.
562  TargetMachine::CodeGenFileType CGFT = TargetMachine::CGFT_AssemblyFile;
563  if (Action == Backend_EmitObj)
564    CGFT = TargetMachine::CGFT_ObjectFile;
565  else if (Action == Backend_EmitMCNull)
566    CGFT = TargetMachine::CGFT_Null;
567  else
568    assert(Action == Backend_EmitAssembly && "Invalid action!");
569
570  // Add ObjC ARC final-cleanup optimizations. This is done as part of the
571  // "codegen" passes so that it isn't run multiple times when there is
572  // inlining happening.
573  if (LangOpts.ObjCAutoRefCount &&
574      CodeGenOpts.OptimizationLevel > 0)
575    PM->add(createObjCARCContractPass());
576
577  if (TM->addPassesToEmitFile(*PM, OS, CGFT,
578                              /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
579    Diags.Report(diag::err_fe_unable_to_interface_with_target);
580    return false;
581  }
582
583  return true;
584}
585
586void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
587                                      raw_pwrite_stream *OS) {
588  TimeRegion Region(llvm::TimePassesIsEnabled ? &CodeGenerationTime : nullptr);
589
590  bool UsesCodeGen = (Action != Backend_EmitNothing &&
591                      Action != Backend_EmitBC &&
592                      Action != Backend_EmitLL);
593  if (!TM)
594    TM.reset(CreateTargetMachine(UsesCodeGen));
595
596  if (UsesCodeGen && !TM) return;
597  CreatePasses();
598
599  switch (Action) {
600  case Backend_EmitNothing:
601    break;
602
603  case Backend_EmitBC:
604    getPerModulePasses()->add(
605        createBitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists));
606    break;
607
608  case Backend_EmitLL:
609    getPerModulePasses()->add(
610        createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
611    break;
612
613  default:
614    if (!AddEmitPasses(Action, *OS))
615      return;
616  }
617
618  // Before executing passes, print the final values of the LLVM options.
619  cl::PrintOptionValues();
620
621  // Run passes. For now we do all passes at once, but eventually we
622  // would like to have the option of streaming code generation.
623
624  if (PerFunctionPasses) {
625    PrettyStackTraceString CrashInfo("Per-function optimization");
626
627    PerFunctionPasses->doInitialization();
628    for (Module::iterator I = TheModule->begin(),
629           E = TheModule->end(); I != E; ++I)
630      if (!I->isDeclaration())
631        PerFunctionPasses->run(*I);
632    PerFunctionPasses->doFinalization();
633  }
634
635  if (PerModulePasses) {
636    PrettyStackTraceString CrashInfo("Per-module optimization passes");
637    PerModulePasses->run(*TheModule);
638  }
639
640  if (CodeGenPasses) {
641    PrettyStackTraceString CrashInfo("Code generation");
642    CodeGenPasses->run(*TheModule);
643  }
644}
645
646void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
647                              const CodeGenOptions &CGOpts,
648                              const clang::TargetOptions &TOpts,
649                              const LangOptions &LOpts, StringRef TDesc,
650                              Module *M, BackendAction Action,
651                              raw_pwrite_stream *OS) {
652  EmitAssemblyHelper AsmHelper(Diags, CGOpts, TOpts, LOpts, M);
653
654  AsmHelper.EmitAssembly(Action, OS);
655
656  // If an optional clang TargetInfo description string was passed in, use it to
657  // verify the LLVM TargetMachine's DataLayout.
658  if (AsmHelper.TM && !TDesc.empty()) {
659    std::string DLDesc =
660        AsmHelper.TM->getDataLayout()->getStringRepresentation();
661    if (DLDesc != TDesc) {
662      unsigned DiagID = Diags.getCustomDiagID(
663          DiagnosticsEngine::Error, "backend data layout '%0' does not match "
664                                    "expected target description '%1'");
665      Diags.Report(DiagID) << DLDesc << TDesc;
666    }
667  }
668}
669