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/StringExtras.h"
18#include "llvm/ADT/StringSwitch.h"
19#include "llvm/Analysis/TargetLibraryInfo.h"
20#include "llvm/Analysis/TargetTransformInfo.h"
21#include "llvm/Bitcode/BitcodeWriterPass.h"
22#include "llvm/CodeGen/RegAllocRegistry.h"
23#include "llvm/CodeGen/SchedulerRegistry.h"
24#include "llvm/IR/DataLayout.h"
25#include "llvm/IR/FunctionInfo.h"
26#include "llvm/IR/IRPrintingPasses.h"
27#include "llvm/IR/LegacyPassManager.h"
28#include "llvm/IR/Module.h"
29#include "llvm/IR/Verifier.h"
30#include "llvm/MC/SubtargetFeature.h"
31#include "llvm/Object/FunctionIndexObjectFile.h"
32#include "llvm/Support/CommandLine.h"
33#include "llvm/Support/PrettyStackTrace.h"
34#include "llvm/Support/TargetRegistry.h"
35#include "llvm/Support/Timer.h"
36#include "llvm/Support/raw_ostream.h"
37#include "llvm/Target/TargetMachine.h"
38#include "llvm/Target/TargetOptions.h"
39#include "llvm/Target/TargetSubtargetInfo.h"
40#include "llvm/Transforms/IPO.h"
41#include "llvm/Transforms/IPO/PassManagerBuilder.h"
42#include "llvm/Transforms/Instrumentation.h"
43#include "llvm/Transforms/ObjCARC.h"
44#include "llvm/Transforms/Scalar.h"
45#include "llvm/Transforms/Utils/SymbolRewriter.h"
46#include <memory>
47using namespace clang;
48using namespace llvm;
49
50namespace {
51
52class EmitAssemblyHelper {
53  DiagnosticsEngine &Diags;
54  const CodeGenOptions &CodeGenOpts;
55  const clang::TargetOptions &TargetOpts;
56  const LangOptions &LangOpts;
57  Module *TheModule;
58
59  Timer CodeGenerationTime;
60
61  mutable legacy::PassManager *CodeGenPasses;
62  mutable legacy::PassManager *PerModulePasses;
63  mutable legacy::FunctionPassManager *PerFunctionPasses;
64
65private:
66  TargetIRAnalysis getTargetIRAnalysis() const {
67    if (TM)
68      return TM->getTargetIRAnalysis();
69
70    return TargetIRAnalysis();
71  }
72
73  legacy::PassManager *getCodeGenPasses() const {
74    if (!CodeGenPasses) {
75      CodeGenPasses = new legacy::PassManager();
76      CodeGenPasses->add(
77          createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
78    }
79    return CodeGenPasses;
80  }
81
82  legacy::PassManager *getPerModulePasses() const {
83    if (!PerModulePasses) {
84      PerModulePasses = new legacy::PassManager();
85      PerModulePasses->add(
86          createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
87    }
88    return PerModulePasses;
89  }
90
91  legacy::FunctionPassManager *getPerFunctionPasses() const {
92    if (!PerFunctionPasses) {
93      PerFunctionPasses = new legacy::FunctionPassManager(TheModule);
94      PerFunctionPasses->add(
95          createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
96    }
97    return PerFunctionPasses;
98  }
99
100  void CreatePasses(FunctionInfoIndex *FunctionIndex);
101
102  /// Generates the TargetMachine.
103  /// Returns Null if it is unable to create the target machine.
104  /// Some of our clang tests specify triples which are not built
105  /// into clang. This is okay because these tests check the generated
106  /// IR, and they require DataLayout which depends on the triple.
107  /// In this case, we allow this method to fail and not report an error.
108  /// When MustCreateTM is used, we print an error if we are unable to load
109  /// the requested target.
110  TargetMachine *CreateTargetMachine(bool MustCreateTM);
111
112  /// Add passes necessary to emit assembly or LLVM IR.
113  ///
114  /// \return True on success.
115  bool AddEmitPasses(BackendAction Action, raw_pwrite_stream &OS);
116
117public:
118  EmitAssemblyHelper(DiagnosticsEngine &_Diags, const CodeGenOptions &CGOpts,
119                     const clang::TargetOptions &TOpts,
120                     const LangOptions &LOpts, Module *M)
121      : Diags(_Diags), CodeGenOpts(CGOpts), TargetOpts(TOpts), LangOpts(LOpts),
122        TheModule(M), CodeGenerationTime("Code Generation Time"),
123        CodeGenPasses(nullptr), PerModulePasses(nullptr),
124        PerFunctionPasses(nullptr) {}
125
126  ~EmitAssemblyHelper() {
127    delete CodeGenPasses;
128    delete PerModulePasses;
129    delete PerFunctionPasses;
130    if (CodeGenOpts.DisableFree)
131      BuryPointer(std::move(TM));
132  }
133
134  std::unique_ptr<TargetMachine> TM;
135
136  void EmitAssembly(BackendAction Action, raw_pwrite_stream *OS);
137};
138
139// We need this wrapper to access LangOpts and CGOpts from extension functions
140// that we add to the PassManagerBuilder.
141class PassManagerBuilderWrapper : public PassManagerBuilder {
142public:
143  PassManagerBuilderWrapper(const CodeGenOptions &CGOpts,
144                            const LangOptions &LangOpts)
145      : PassManagerBuilder(), CGOpts(CGOpts), LangOpts(LangOpts) {}
146  const CodeGenOptions &getCGOpts() const { return CGOpts; }
147  const LangOptions &getLangOpts() const { return LangOpts; }
148private:
149  const CodeGenOptions &CGOpts;
150  const LangOptions &LangOpts;
151};
152
153}
154
155static void addObjCARCAPElimPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
156  if (Builder.OptLevel > 0)
157    PM.add(createObjCARCAPElimPass());
158}
159
160static void addObjCARCExpandPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
161  if (Builder.OptLevel > 0)
162    PM.add(createObjCARCExpandPass());
163}
164
165static void addObjCARCOptPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
166  if (Builder.OptLevel > 0)
167    PM.add(createObjCARCOptPass());
168}
169
170static void addAddDiscriminatorsPass(const PassManagerBuilder &Builder,
171                                     legacy::PassManagerBase &PM) {
172  PM.add(createAddDiscriminatorsPass());
173}
174
175static void addBoundsCheckingPass(const PassManagerBuilder &Builder,
176                                    legacy::PassManagerBase &PM) {
177  PM.add(createBoundsCheckingPass());
178}
179
180static void addSanitizerCoveragePass(const PassManagerBuilder &Builder,
181                                     legacy::PassManagerBase &PM) {
182  const PassManagerBuilderWrapper &BuilderWrapper =
183      static_cast<const PassManagerBuilderWrapper&>(Builder);
184  const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
185  SanitizerCoverageOptions Opts;
186  Opts.CoverageType =
187      static_cast<SanitizerCoverageOptions::Type>(CGOpts.SanitizeCoverageType);
188  Opts.IndirectCalls = CGOpts.SanitizeCoverageIndirectCalls;
189  Opts.TraceBB = CGOpts.SanitizeCoverageTraceBB;
190  Opts.TraceCmp = CGOpts.SanitizeCoverageTraceCmp;
191  Opts.Use8bitCounters = CGOpts.SanitizeCoverage8bitCounters;
192  PM.add(createSanitizerCoverageModulePass(Opts));
193}
194
195static void addAddressSanitizerPasses(const PassManagerBuilder &Builder,
196                                      legacy::PassManagerBase &PM) {
197  const PassManagerBuilderWrapper &BuilderWrapper =
198      static_cast<const PassManagerBuilderWrapper&>(Builder);
199  const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
200  bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Address);
201  PM.add(createAddressSanitizerFunctionPass(/*CompileKernel*/false, Recover));
202  PM.add(createAddressSanitizerModulePass(/*CompileKernel*/false, Recover));
203}
204
205static void addKernelAddressSanitizerPasses(const PassManagerBuilder &Builder,
206                                            legacy::PassManagerBase &PM) {
207  PM.add(createAddressSanitizerFunctionPass(/*CompileKernel*/true,
208                                            /*Recover*/true));
209  PM.add(createAddressSanitizerModulePass(/*CompileKernel*/true,
210                                          /*Recover*/true));
211}
212
213static void addMemorySanitizerPass(const PassManagerBuilder &Builder,
214                                   legacy::PassManagerBase &PM) {
215  const PassManagerBuilderWrapper &BuilderWrapper =
216      static_cast<const PassManagerBuilderWrapper&>(Builder);
217  const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
218  PM.add(createMemorySanitizerPass(CGOpts.SanitizeMemoryTrackOrigins));
219
220  // MemorySanitizer inserts complex instrumentation that mostly follows
221  // the logic of the original code, but operates on "shadow" values.
222  // It can benefit from re-running some general purpose optimization passes.
223  if (Builder.OptLevel > 0) {
224    PM.add(createEarlyCSEPass());
225    PM.add(createReassociatePass());
226    PM.add(createLICMPass());
227    PM.add(createGVNPass());
228    PM.add(createInstructionCombiningPass());
229    PM.add(createDeadStoreEliminationPass());
230  }
231}
232
233static void addThreadSanitizerPass(const PassManagerBuilder &Builder,
234                                   legacy::PassManagerBase &PM) {
235  PM.add(createThreadSanitizerPass());
236}
237
238static void addDataFlowSanitizerPass(const PassManagerBuilder &Builder,
239                                     legacy::PassManagerBase &PM) {
240  const PassManagerBuilderWrapper &BuilderWrapper =
241      static_cast<const PassManagerBuilderWrapper&>(Builder);
242  const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
243  PM.add(createDataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
244}
245
246static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
247                                         const CodeGenOptions &CodeGenOpts) {
248  TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple);
249  if (!CodeGenOpts.SimplifyLibCalls)
250    TLII->disableAllFunctions();
251  else {
252    // Disable individual libc/libm calls in TargetLibraryInfo.
253    LibFunc::Func F;
254    for (auto &FuncName : CodeGenOpts.getNoBuiltinFuncs())
255      if (TLII->getLibFunc(FuncName, F))
256        TLII->setUnavailable(F);
257  }
258
259  switch (CodeGenOpts.getVecLib()) {
260  case CodeGenOptions::Accelerate:
261    TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::Accelerate);
262    break;
263  default:
264    break;
265  }
266  return TLII;
267}
268
269static void addSymbolRewriterPass(const CodeGenOptions &Opts,
270                                  legacy::PassManager *MPM) {
271  llvm::SymbolRewriter::RewriteDescriptorList DL;
272
273  llvm::SymbolRewriter::RewriteMapParser MapParser;
274  for (const auto &MapFile : Opts.RewriteMapFiles)
275    MapParser.parse(MapFile, &DL);
276
277  MPM->add(createRewriteSymbolsPass(DL));
278}
279
280void EmitAssemblyHelper::CreatePasses(FunctionInfoIndex *FunctionIndex) {
281  if (CodeGenOpts.DisableLLVMPasses)
282    return;
283
284  unsigned OptLevel = CodeGenOpts.OptimizationLevel;
285  CodeGenOptions::InliningMethod Inlining = CodeGenOpts.getInlining();
286
287  // Handle disabling of LLVM optimization, where we want to preserve the
288  // internal module before any optimization.
289  if (CodeGenOpts.DisableLLVMOpts) {
290    OptLevel = 0;
291    Inlining = CodeGenOpts.NoInlining;
292  }
293
294  PassManagerBuilderWrapper PMBuilder(CodeGenOpts, LangOpts);
295
296  // Figure out TargetLibraryInfo.
297  Triple TargetTriple(TheModule->getTargetTriple());
298  PMBuilder.LibraryInfo = createTLII(TargetTriple, CodeGenOpts);
299
300  switch (Inlining) {
301  case CodeGenOptions::NoInlining:
302    break;
303  case CodeGenOptions::NormalInlining: {
304    PMBuilder.Inliner =
305        createFunctionInliningPass(OptLevel, CodeGenOpts.OptimizeSize);
306    break;
307  }
308  case CodeGenOptions::OnlyAlwaysInlining:
309    // Respect always_inline.
310    if (OptLevel == 0)
311      // Do not insert lifetime intrinsics at -O0.
312      PMBuilder.Inliner = createAlwaysInlinerPass(false);
313    else
314      PMBuilder.Inliner = createAlwaysInlinerPass();
315    break;
316  }
317
318  PMBuilder.OptLevel = OptLevel;
319  PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
320  PMBuilder.BBVectorize = CodeGenOpts.VectorizeBB;
321  PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
322  PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
323
324  PMBuilder.DisableUnitAtATime = !CodeGenOpts.UnitAtATime;
325  PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
326  PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
327  PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
328  PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
329
330  legacy::PassManager *MPM = getPerModulePasses();
331
332  // If we are performing a ThinLTO importing compile, invoke the LTO
333  // pipeline and pass down the in-memory function index.
334  if (FunctionIndex) {
335    PMBuilder.FunctionIndex = FunctionIndex;
336    PMBuilder.populateLTOPassManager(*MPM);
337    return;
338  }
339
340  PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
341                         addAddDiscriminatorsPass);
342
343  // In ObjC ARC mode, add the main ARC optimization passes.
344  if (LangOpts.ObjCAutoRefCount) {
345    PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
346                           addObjCARCExpandPass);
347    PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
348                           addObjCARCAPElimPass);
349    PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
350                           addObjCARCOptPass);
351  }
352
353  if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds)) {
354    PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
355                           addBoundsCheckingPass);
356    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
357                           addBoundsCheckingPass);
358  }
359
360  if (CodeGenOpts.SanitizeCoverageType ||
361      CodeGenOpts.SanitizeCoverageIndirectCalls ||
362      CodeGenOpts.SanitizeCoverageTraceCmp) {
363    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
364                           addSanitizerCoveragePass);
365    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
366                           addSanitizerCoveragePass);
367  }
368
369  if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
370    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
371                           addAddressSanitizerPasses);
372    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
373                           addAddressSanitizerPasses);
374  }
375
376  if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
377    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
378                           addKernelAddressSanitizerPasses);
379    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
380                           addKernelAddressSanitizerPasses);
381  }
382
383  if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
384    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
385                           addMemorySanitizerPass);
386    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
387                           addMemorySanitizerPass);
388  }
389
390  if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
391    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
392                           addThreadSanitizerPass);
393    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
394                           addThreadSanitizerPass);
395  }
396
397  if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
398    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
399                           addDataFlowSanitizerPass);
400    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
401                           addDataFlowSanitizerPass);
402  }
403
404  // Set up the per-function pass manager.
405  legacy::FunctionPassManager *FPM = getPerFunctionPasses();
406  if (CodeGenOpts.VerifyModule)
407    FPM->add(createVerifierPass());
408  PMBuilder.populateFunctionPassManager(*FPM);
409
410  // Set up the per-module pass manager.
411  if (!CodeGenOpts.RewriteMapFiles.empty())
412    addSymbolRewriterPass(CodeGenOpts, MPM);
413
414  if (!CodeGenOpts.DisableGCov &&
415      (CodeGenOpts.EmitGcovArcs || CodeGenOpts.EmitGcovNotes)) {
416    // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
417    // LLVM's -default-gcov-version flag is set to something invalid.
418    GCOVOptions Options;
419    Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
420    Options.EmitData = CodeGenOpts.EmitGcovArcs;
421    memcpy(Options.Version, CodeGenOpts.CoverageVersion, 4);
422    Options.UseCfgChecksum = CodeGenOpts.CoverageExtraChecksum;
423    Options.NoRedZone = CodeGenOpts.DisableRedZone;
424    Options.FunctionNamesInData =
425        !CodeGenOpts.CoverageNoFunctionNamesInData;
426    Options.ExitBlockBeforeBody = CodeGenOpts.CoverageExitBlockBeforeBody;
427    MPM->add(createGCOVProfilerPass(Options));
428    if (CodeGenOpts.getDebugInfo() == CodeGenOptions::NoDebugInfo)
429      MPM->add(createStripSymbolsPass(true));
430  }
431
432  if (CodeGenOpts.ProfileInstrGenerate) {
433    InstrProfOptions Options;
434    Options.NoRedZone = CodeGenOpts.DisableRedZone;
435    Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
436    MPM->add(createInstrProfilingPass(Options));
437  }
438
439  if (!CodeGenOpts.SampleProfileFile.empty())
440    MPM->add(createSampleProfileLoaderPass(CodeGenOpts.SampleProfileFile));
441
442  PMBuilder.populateModulePassManager(*MPM);
443}
444
445TargetMachine *EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
446  // Create the TargetMachine for generating code.
447  std::string Error;
448  std::string Triple = TheModule->getTargetTriple();
449  const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
450  if (!TheTarget) {
451    if (MustCreateTM)
452      Diags.Report(diag::err_fe_unable_to_create_target) << Error;
453    return nullptr;
454  }
455
456  unsigned CodeModel =
457    llvm::StringSwitch<unsigned>(CodeGenOpts.CodeModel)
458      .Case("small", llvm::CodeModel::Small)
459      .Case("kernel", llvm::CodeModel::Kernel)
460      .Case("medium", llvm::CodeModel::Medium)
461      .Case("large", llvm::CodeModel::Large)
462      .Case("default", llvm::CodeModel::Default)
463      .Default(~0u);
464  assert(CodeModel != ~0u && "invalid code model!");
465  llvm::CodeModel::Model CM = static_cast<llvm::CodeModel::Model>(CodeModel);
466
467  SmallVector<const char *, 16> BackendArgs;
468  BackendArgs.push_back("clang"); // Fake program name.
469  if (!CodeGenOpts.DebugPass.empty()) {
470    BackendArgs.push_back("-debug-pass");
471    BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
472  }
473  if (!CodeGenOpts.LimitFloatPrecision.empty()) {
474    BackendArgs.push_back("-limit-float-precision");
475    BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
476  }
477  for (const std::string &BackendOption : CodeGenOpts.BackendOptions)
478    BackendArgs.push_back(BackendOption.c_str());
479  BackendArgs.push_back(nullptr);
480  llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
481                                    BackendArgs.data());
482
483  std::string FeaturesStr =
484      llvm::join(TargetOpts.Features.begin(), TargetOpts.Features.end(), ",");
485
486  // Keep this synced with the equivalent code in tools/driver/cc1as_main.cpp.
487  llvm::Reloc::Model RM = llvm::Reloc::Default;
488  if (CodeGenOpts.RelocationModel == "static") {
489    RM = llvm::Reloc::Static;
490  } else if (CodeGenOpts.RelocationModel == "pic") {
491    RM = llvm::Reloc::PIC_;
492  } else {
493    assert(CodeGenOpts.RelocationModel == "dynamic-no-pic" &&
494           "Invalid PIC model!");
495    RM = llvm::Reloc::DynamicNoPIC;
496  }
497
498  CodeGenOpt::Level OptLevel = CodeGenOpt::Default;
499  switch (CodeGenOpts.OptimizationLevel) {
500  default: break;
501  case 0: OptLevel = CodeGenOpt::None; break;
502  case 3: OptLevel = CodeGenOpt::Aggressive; break;
503  }
504
505  llvm::TargetOptions Options;
506
507  if (!TargetOpts.Reciprocals.empty())
508    Options.Reciprocals = TargetRecip(TargetOpts.Reciprocals);
509
510  Options.ThreadModel =
511    llvm::StringSwitch<llvm::ThreadModel::Model>(CodeGenOpts.ThreadModel)
512      .Case("posix", llvm::ThreadModel::POSIX)
513      .Case("single", llvm::ThreadModel::Single);
514
515  // Set float ABI type.
516  assert((CodeGenOpts.FloatABI == "soft" || CodeGenOpts.FloatABI == "softfp" ||
517          CodeGenOpts.FloatABI == "hard" || CodeGenOpts.FloatABI.empty()) &&
518         "Invalid Floating Point ABI!");
519  Options.FloatABIType =
520      llvm::StringSwitch<llvm::FloatABI::ABIType>(CodeGenOpts.FloatABI)
521          .Case("soft", llvm::FloatABI::Soft)
522          .Case("softfp", llvm::FloatABI::Soft)
523          .Case("hard", llvm::FloatABI::Hard)
524          .Default(llvm::FloatABI::Default);
525
526  // Set FP fusion mode.
527  switch (CodeGenOpts.getFPContractMode()) {
528  case CodeGenOptions::FPC_Off:
529    Options.AllowFPOpFusion = llvm::FPOpFusion::Strict;
530    break;
531  case CodeGenOptions::FPC_On:
532    Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
533    break;
534  case CodeGenOptions::FPC_Fast:
535    Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
536    break;
537  }
538
539  Options.UseInitArray = CodeGenOpts.UseInitArray;
540  Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
541  Options.CompressDebugSections = CodeGenOpts.CompressDebugSections;
542
543  // Set EABI version.
544  Options.EABIVersion = llvm::StringSwitch<llvm::EABI>(CodeGenOpts.EABIVersion)
545                            .Case("4", llvm::EABI::EABI4)
546                            .Case("5", llvm::EABI::EABI5)
547                            .Case("gnu", llvm::EABI::GNU)
548                            .Default(llvm::EABI::Default);
549
550  Options.LessPreciseFPMADOption = CodeGenOpts.LessPreciseFPMAD;
551  Options.NoInfsFPMath = CodeGenOpts.NoInfsFPMath;
552  Options.NoNaNsFPMath = CodeGenOpts.NoNaNsFPMath;
553  Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
554  Options.UnsafeFPMath = CodeGenOpts.UnsafeFPMath;
555  Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
556  Options.PositionIndependentExecutable = LangOpts.PIELevel != 0;
557  Options.FunctionSections = CodeGenOpts.FunctionSections;
558  Options.DataSections = CodeGenOpts.DataSections;
559  Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
560  Options.EmulatedTLS = CodeGenOpts.EmulatedTLS;
561  switch (CodeGenOpts.getDebuggerTuning()) {
562  case CodeGenOptions::DebuggerKindGDB:
563    Options.DebuggerTuning = llvm::DebuggerKind::GDB;
564    break;
565  case CodeGenOptions::DebuggerKindLLDB:
566    Options.DebuggerTuning = llvm::DebuggerKind::LLDB;
567    break;
568  case CodeGenOptions::DebuggerKindSCE:
569    Options.DebuggerTuning = llvm::DebuggerKind::SCE;
570    break;
571  default:
572    break;
573  }
574
575  Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
576  Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
577  Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
578  Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
579  Options.MCOptions.MCIncrementalLinkerCompatible =
580      CodeGenOpts.IncrementalLinkerCompatible;
581  Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
582  Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
583  Options.MCOptions.ABIName = TargetOpts.ABI;
584
585  TargetMachine *TM = TheTarget->createTargetMachine(Triple, TargetOpts.CPU,
586                                                     FeaturesStr, Options,
587                                                     RM, CM, OptLevel);
588
589  return TM;
590}
591
592bool EmitAssemblyHelper::AddEmitPasses(BackendAction Action,
593                                       raw_pwrite_stream &OS) {
594
595  // Create the code generator passes.
596  legacy::PassManager *PM = getCodeGenPasses();
597
598  // Add LibraryInfo.
599  llvm::Triple TargetTriple(TheModule->getTargetTriple());
600  std::unique_ptr<TargetLibraryInfoImpl> TLII(
601      createTLII(TargetTriple, CodeGenOpts));
602  PM->add(new TargetLibraryInfoWrapperPass(*TLII));
603
604  // Normal mode, emit a .s or .o file by running the code generator. Note,
605  // this also adds codegenerator level optimization passes.
606  TargetMachine::CodeGenFileType CGFT = TargetMachine::CGFT_AssemblyFile;
607  if (Action == Backend_EmitObj)
608    CGFT = TargetMachine::CGFT_ObjectFile;
609  else if (Action == Backend_EmitMCNull)
610    CGFT = TargetMachine::CGFT_Null;
611  else
612    assert(Action == Backend_EmitAssembly && "Invalid action!");
613
614  // Add ObjC ARC final-cleanup optimizations. This is done as part of the
615  // "codegen" passes so that it isn't run multiple times when there is
616  // inlining happening.
617  if (CodeGenOpts.OptimizationLevel > 0)
618    PM->add(createObjCARCContractPass());
619
620  if (TM->addPassesToEmitFile(*PM, OS, CGFT,
621                              /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
622    Diags.Report(diag::err_fe_unable_to_interface_with_target);
623    return false;
624  }
625
626  return true;
627}
628
629void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
630                                      raw_pwrite_stream *OS) {
631  TimeRegion Region(llvm::TimePassesIsEnabled ? &CodeGenerationTime : nullptr);
632
633  bool UsesCodeGen = (Action != Backend_EmitNothing &&
634                      Action != Backend_EmitBC &&
635                      Action != Backend_EmitLL);
636  if (!TM)
637    TM.reset(CreateTargetMachine(UsesCodeGen));
638
639  if (UsesCodeGen && !TM)
640    return;
641  if (TM)
642    TheModule->setDataLayout(TM->createDataLayout());
643
644  // If we are performing a ThinLTO importing compile, load the function
645  // index into memory and pass it into CreatePasses, which will add it
646  // to the PassManagerBuilder and invoke LTO passes.
647  std::unique_ptr<FunctionInfoIndex> FunctionIndex;
648  if (!CodeGenOpts.ThinLTOIndexFile.empty()) {
649    ErrorOr<std::unique_ptr<FunctionInfoIndex>> IndexOrErr =
650        llvm::getFunctionIndexForFile(CodeGenOpts.ThinLTOIndexFile,
651                                      [&](const DiagnosticInfo &DI) {
652                                        TheModule->getContext().diagnose(DI);
653                                      });
654    if (std::error_code EC = IndexOrErr.getError()) {
655      std::string Error = EC.message();
656      errs() << "Error loading index file '" << CodeGenOpts.ThinLTOIndexFile
657             << "': " << Error << "\n";
658      return;
659    }
660    FunctionIndex = std::move(IndexOrErr.get());
661    assert(FunctionIndex && "Expected non-empty function index");
662  }
663
664  CreatePasses(FunctionIndex.get());
665
666  switch (Action) {
667  case Backend_EmitNothing:
668    break;
669
670  case Backend_EmitBC:
671    getPerModulePasses()->add(createBitcodeWriterPass(
672        *OS, CodeGenOpts.EmitLLVMUseLists, CodeGenOpts.EmitFunctionSummary));
673    break;
674
675  case Backend_EmitLL:
676    getPerModulePasses()->add(
677        createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
678    break;
679
680  default:
681    if (!AddEmitPasses(Action, *OS))
682      return;
683  }
684
685  // Before executing passes, print the final values of the LLVM options.
686  cl::PrintOptionValues();
687
688  // Run passes. For now we do all passes at once, but eventually we
689  // would like to have the option of streaming code generation.
690
691  if (PerFunctionPasses) {
692    PrettyStackTraceString CrashInfo("Per-function optimization");
693
694    PerFunctionPasses->doInitialization();
695    for (Function &F : *TheModule)
696      if (!F.isDeclaration())
697        PerFunctionPasses->run(F);
698    PerFunctionPasses->doFinalization();
699  }
700
701  if (PerModulePasses) {
702    PrettyStackTraceString CrashInfo("Per-module optimization passes");
703    PerModulePasses->run(*TheModule);
704  }
705
706  if (CodeGenPasses) {
707    PrettyStackTraceString CrashInfo("Code generation");
708    CodeGenPasses->run(*TheModule);
709  }
710}
711
712void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
713                              const CodeGenOptions &CGOpts,
714                              const clang::TargetOptions &TOpts,
715                              const LangOptions &LOpts, StringRef TDesc,
716                              Module *M, BackendAction Action,
717                              raw_pwrite_stream *OS) {
718  EmitAssemblyHelper AsmHelper(Diags, CGOpts, TOpts, LOpts, M);
719
720  AsmHelper.EmitAssembly(Action, OS);
721
722  // If an optional clang TargetInfo description string was passed in, use it to
723  // verify the LLVM TargetMachine's DataLayout.
724  if (AsmHelper.TM && !TDesc.empty()) {
725    std::string DLDesc = M->getDataLayout().getStringRepresentation();
726    if (DLDesc != TDesc) {
727      unsigned DiagID = Diags.getCustomDiagID(
728          DiagnosticsEngine::Error, "backend data layout '%0' does not match "
729                                    "expected target description '%1'");
730      Diags.Report(DiagID) << DLDesc << TDesc;
731    }
732  }
733}
734