BackendUtil.cpp revision 288943 
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  SanitizerCoverageOptions Opts;
193  Opts.CoverageType =
194      static_cast<SanitizerCoverageOptions::Type>(CGOpts.SanitizeCoverageType);
195  Opts.IndirectCalls = CGOpts.SanitizeCoverageIndirectCalls;
196  Opts.TraceBB = CGOpts.SanitizeCoverageTraceBB;
197  Opts.TraceCmp = CGOpts.SanitizeCoverageTraceCmp;
198  Opts.Use8bitCounters = CGOpts.SanitizeCoverage8bitCounters;
199  PM.add(createSanitizerCoverageModulePass(Opts));
200}
201
202static void addAddressSanitizerPasses(const PassManagerBuilder &Builder,
203                                      legacy::PassManagerBase &PM) {
204  PM.add(createAddressSanitizerFunctionPass(/*CompileKernel*/false));
205  PM.add(createAddressSanitizerModulePass(/*CompileKernel*/false));
206}
207
208static void addKernelAddressSanitizerPasses(const PassManagerBuilder &Builder,
209                                            legacy::PassManagerBase &PM) {
210  PM.add(createAddressSanitizerFunctionPass(/*CompileKernel*/true));
211  PM.add(createAddressSanitizerModulePass(/*CompileKernel*/true));
212}
213
214static void addMemorySanitizerPass(const PassManagerBuilder &Builder,
215                                   legacy::PassManagerBase &PM) {
216  const PassManagerBuilderWrapper &BuilderWrapper =
217      static_cast<const PassManagerBuilderWrapper&>(Builder);
218  const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
219  PM.add(createMemorySanitizerPass(CGOpts.SanitizeMemoryTrackOrigins));
220
221  // MemorySanitizer inserts complex instrumentation that mostly follows
222  // the logic of the original code, but operates on "shadow" values.
223  // It can benefit from re-running some general purpose optimization passes.
224  if (Builder.OptLevel > 0) {
225    PM.add(createEarlyCSEPass());
226    PM.add(createReassociatePass());
227    PM.add(createLICMPass());
228    PM.add(createGVNPass());
229    PM.add(createInstructionCombiningPass());
230    PM.add(createDeadStoreEliminationPass());
231  }
232}
233
234static void addThreadSanitizerPass(const PassManagerBuilder &Builder,
235                                   legacy::PassManagerBase &PM) {
236  PM.add(createThreadSanitizerPass());
237}
238
239static void addDataFlowSanitizerPass(const PassManagerBuilder &Builder,
240                                     legacy::PassManagerBase &PM) {
241  const PassManagerBuilderWrapper &BuilderWrapper =
242      static_cast<const PassManagerBuilderWrapper&>(Builder);
243  const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
244  PM.add(createDataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
245}
246
247static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
248                                         const CodeGenOptions &CodeGenOpts) {
249  TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple);
250  if (!CodeGenOpts.SimplifyLibCalls)
251    TLII->disableAllFunctions();
252
253  switch (CodeGenOpts.getVecLib()) {
254  case CodeGenOptions::Accelerate:
255    TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::Accelerate);
256    break;
257  default:
258    break;
259  }
260  return TLII;
261}
262
263static void addSymbolRewriterPass(const CodeGenOptions &Opts,
264                                  legacy::PassManager *MPM) {
265  llvm::SymbolRewriter::RewriteDescriptorList DL;
266
267  llvm::SymbolRewriter::RewriteMapParser MapParser;
268  for (const auto &MapFile : Opts.RewriteMapFiles)
269    MapParser.parse(MapFile, &DL);
270
271  MPM->add(createRewriteSymbolsPass(DL));
272}
273
274void EmitAssemblyHelper::CreatePasses() {
275  unsigned OptLevel = CodeGenOpts.OptimizationLevel;
276  CodeGenOptions::InliningMethod Inlining = CodeGenOpts.getInlining();
277
278  // Handle disabling of LLVM optimization, where we want to preserve the
279  // internal module before any optimization.
280  if (CodeGenOpts.DisableLLVMOpts) {
281    OptLevel = 0;
282    Inlining = CodeGenOpts.NoInlining;
283  }
284
285  PassManagerBuilderWrapper PMBuilder(CodeGenOpts, LangOpts);
286  PMBuilder.OptLevel = OptLevel;
287  PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
288  PMBuilder.BBVectorize = CodeGenOpts.VectorizeBB;
289  PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
290  PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
291
292  PMBuilder.DisableUnitAtATime = !CodeGenOpts.UnitAtATime;
293  PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
294  PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
295  PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
296  PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
297
298  PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
299                         addAddDiscriminatorsPass);
300
301  if (!CodeGenOpts.SampleProfileFile.empty())
302    PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
303                           addSampleProfileLoaderPass);
304
305  // In ObjC ARC mode, add the main ARC optimization passes.
306  if (LangOpts.ObjCAutoRefCount) {
307    PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
308                           addObjCARCExpandPass);
309    PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
310                           addObjCARCAPElimPass);
311    PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
312                           addObjCARCOptPass);
313  }
314
315  if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds)) {
316    PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
317                           addBoundsCheckingPass);
318    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
319                           addBoundsCheckingPass);
320  }
321
322  if (CodeGenOpts.SanitizeCoverageType ||
323      CodeGenOpts.SanitizeCoverageIndirectCalls ||
324      CodeGenOpts.SanitizeCoverageTraceCmp) {
325    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
326                           addSanitizerCoveragePass);
327    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
328                           addSanitizerCoveragePass);
329  }
330
331  if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
332    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
333                           addAddressSanitizerPasses);
334    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
335                           addAddressSanitizerPasses);
336  }
337
338  if (LangOpts.Sanitize.has(SanitizerKind::KernelAddress)) {
339    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
340                           addKernelAddressSanitizerPasses);
341    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
342                           addKernelAddressSanitizerPasses);
343  }
344
345  if (LangOpts.Sanitize.has(SanitizerKind::Memory)) {
346    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
347                           addMemorySanitizerPass);
348    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
349                           addMemorySanitizerPass);
350  }
351
352  if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
353    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
354                           addThreadSanitizerPass);
355    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
356                           addThreadSanitizerPass);
357  }
358
359  if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
360    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
361                           addDataFlowSanitizerPass);
362    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
363                           addDataFlowSanitizerPass);
364  }
365
366  // Figure out TargetLibraryInfo.
367  Triple TargetTriple(TheModule->getTargetTriple());
368  PMBuilder.LibraryInfo = createTLII(TargetTriple, CodeGenOpts);
369
370  switch (Inlining) {
371  case CodeGenOptions::NoInlining: break;
372  case CodeGenOptions::NormalInlining: {
373    PMBuilder.Inliner =
374        createFunctionInliningPass(OptLevel, CodeGenOpts.OptimizeSize);
375    break;
376  }
377  case CodeGenOptions::OnlyAlwaysInlining:
378    // Respect always_inline.
379    if (OptLevel == 0)
380      // Do not insert lifetime intrinsics at -O0.
381      PMBuilder.Inliner = createAlwaysInlinerPass(false);
382    else
383      PMBuilder.Inliner = createAlwaysInlinerPass();
384    break;
385  }
386
387  // Set up the per-function pass manager.
388  legacy::FunctionPassManager *FPM = getPerFunctionPasses();
389  if (CodeGenOpts.VerifyModule)
390    FPM->add(createVerifierPass());
391  PMBuilder.populateFunctionPassManager(*FPM);
392
393  // Set up the per-module pass manager.
394  legacy::PassManager *MPM = getPerModulePasses();
395  if (!CodeGenOpts.RewriteMapFiles.empty())
396    addSymbolRewriterPass(CodeGenOpts, MPM);
397
398  if (!CodeGenOpts.DisableGCov &&
399      (CodeGenOpts.EmitGcovArcs || CodeGenOpts.EmitGcovNotes)) {
400    // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
401    // LLVM's -default-gcov-version flag is set to something invalid.
402    GCOVOptions Options;
403    Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
404    Options.EmitData = CodeGenOpts.EmitGcovArcs;
405    memcpy(Options.Version, CodeGenOpts.CoverageVersion, 4);
406    Options.UseCfgChecksum = CodeGenOpts.CoverageExtraChecksum;
407    Options.NoRedZone = CodeGenOpts.DisableRedZone;
408    Options.FunctionNamesInData =
409        !CodeGenOpts.CoverageNoFunctionNamesInData;
410    Options.ExitBlockBeforeBody = CodeGenOpts.CoverageExitBlockBeforeBody;
411    MPM->add(createGCOVProfilerPass(Options));
412    if (CodeGenOpts.getDebugInfo() == CodeGenOptions::NoDebugInfo)
413      MPM->add(createStripSymbolsPass(true));
414  }
415
416  if (CodeGenOpts.ProfileInstrGenerate) {
417    InstrProfOptions Options;
418    Options.NoRedZone = CodeGenOpts.DisableRedZone;
419    Options.InstrProfileOutput = CodeGenOpts.InstrProfileOutput;
420    MPM->add(createInstrProfilingPass(Options));
421  }
422
423  PMBuilder.populateModulePassManager(*MPM);
424}
425
426TargetMachine *EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
427  // Create the TargetMachine for generating code.
428  std::string Error;
429  std::string Triple = TheModule->getTargetTriple();
430  const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
431  if (!TheTarget) {
432    if (MustCreateTM)
433      Diags.Report(diag::err_fe_unable_to_create_target) << Error;
434    return nullptr;
435  }
436
437  unsigned CodeModel =
438    llvm::StringSwitch<unsigned>(CodeGenOpts.CodeModel)
439      .Case("small", llvm::CodeModel::Small)
440      .Case("kernel", llvm::CodeModel::Kernel)
441      .Case("medium", llvm::CodeModel::Medium)
442      .Case("large", llvm::CodeModel::Large)
443      .Case("default", llvm::CodeModel::Default)
444      .Default(~0u);
445  assert(CodeModel != ~0u && "invalid code model!");
446  llvm::CodeModel::Model CM = static_cast<llvm::CodeModel::Model>(CodeModel);
447
448  SmallVector<const char *, 16> BackendArgs;
449  BackendArgs.push_back("clang"); // Fake program name.
450  if (!CodeGenOpts.DebugPass.empty()) {
451    BackendArgs.push_back("-debug-pass");
452    BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
453  }
454  if (!CodeGenOpts.LimitFloatPrecision.empty()) {
455    BackendArgs.push_back("-limit-float-precision");
456    BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
457  }
458  for (unsigned i = 0, e = CodeGenOpts.BackendOptions.size(); i != e; ++i)
459    BackendArgs.push_back(CodeGenOpts.BackendOptions[i].c_str());
460  BackendArgs.push_back(nullptr);
461  llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
462                                    BackendArgs.data());
463
464  std::string FeaturesStr;
465  if (!TargetOpts.Features.empty()) {
466    SubtargetFeatures Features;
467    for (const std::string &Feature : TargetOpts.Features)
468      Features.AddFeature(Feature);
469    FeaturesStr = Features.getString();
470  }
471
472  llvm::Reloc::Model RM = llvm::Reloc::Default;
473  if (CodeGenOpts.RelocationModel == "static") {
474    RM = llvm::Reloc::Static;
475  } else if (CodeGenOpts.RelocationModel == "pic") {
476    RM = llvm::Reloc::PIC_;
477  } else {
478    assert(CodeGenOpts.RelocationModel == "dynamic-no-pic" &&
479           "Invalid PIC model!");
480    RM = llvm::Reloc::DynamicNoPIC;
481  }
482
483  CodeGenOpt::Level OptLevel = CodeGenOpt::Default;
484  switch (CodeGenOpts.OptimizationLevel) {
485  default: break;
486  case 0: OptLevel = CodeGenOpt::None; break;
487  case 3: OptLevel = CodeGenOpt::Aggressive; break;
488  }
489
490  llvm::TargetOptions Options;
491
492  if (!TargetOpts.Reciprocals.empty())
493    Options.Reciprocals = TargetRecip(TargetOpts.Reciprocals);
494
495  Options.ThreadModel =
496    llvm::StringSwitch<llvm::ThreadModel::Model>(CodeGenOpts.ThreadModel)
497      .Case("posix", llvm::ThreadModel::POSIX)
498      .Case("single", llvm::ThreadModel::Single);
499
500  if (CodeGenOpts.DisableIntegratedAS)
501    Options.DisableIntegratedAS = true;
502
503  if (CodeGenOpts.CompressDebugSections)
504    Options.CompressDebugSections = true;
505
506  if (CodeGenOpts.UseInitArray)
507    Options.UseInitArray = true;
508
509  // Set float ABI type.
510  if (CodeGenOpts.FloatABI == "soft" || CodeGenOpts.FloatABI == "softfp")
511    Options.FloatABIType = llvm::FloatABI::Soft;
512  else if (CodeGenOpts.FloatABI == "hard")
513    Options.FloatABIType = llvm::FloatABI::Hard;
514  else {
515    assert(CodeGenOpts.FloatABI.empty() && "Invalid float abi!");
516    Options.FloatABIType = llvm::FloatABI::Default;
517  }
518
519  // Set FP fusion mode.
520  switch (CodeGenOpts.getFPContractMode()) {
521  case CodeGenOptions::FPC_Off:
522    Options.AllowFPOpFusion = llvm::FPOpFusion::Strict;
523    break;
524  case CodeGenOptions::FPC_On:
525    Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
526    break;
527  case CodeGenOptions::FPC_Fast:
528    Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
529    break;
530  }
531
532  Options.LessPreciseFPMADOption = CodeGenOpts.LessPreciseFPMAD;
533  Options.NoInfsFPMath = CodeGenOpts.NoInfsFPMath;
534  Options.NoNaNsFPMath = CodeGenOpts.NoNaNsFPMath;
535  Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
536  Options.UnsafeFPMath = CodeGenOpts.UnsafeFPMath;
537  Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
538  Options.PositionIndependentExecutable = LangOpts.PIELevel != 0;
539  Options.FunctionSections = CodeGenOpts.FunctionSections;
540  Options.DataSections = CodeGenOpts.DataSections;
541  Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
542
543  Options.MCOptions.MCRelaxAll = CodeGenOpts.RelaxAll;
544  Options.MCOptions.MCSaveTempLabels = CodeGenOpts.SaveTempLabels;
545  Options.MCOptions.MCUseDwarfDirectory = !CodeGenOpts.NoDwarfDirectoryAsm;
546  Options.MCOptions.MCNoExecStack = CodeGenOpts.NoExecStack;
547  Options.MCOptions.MCFatalWarnings = CodeGenOpts.FatalWarnings;
548  Options.MCOptions.AsmVerbose = CodeGenOpts.AsmVerbose;
549  Options.MCOptions.ABIName = TargetOpts.ABI;
550
551  TargetMachine *TM = TheTarget->createTargetMachine(Triple, TargetOpts.CPU,
552                                                     FeaturesStr, Options,
553                                                     RM, CM, OptLevel);
554
555  return TM;
556}
557
558bool EmitAssemblyHelper::AddEmitPasses(BackendAction Action,
559                                       raw_pwrite_stream &OS) {
560
561  // Create the code generator passes.
562  legacy::PassManager *PM = getCodeGenPasses();
563
564  // Add LibraryInfo.
565  llvm::Triple TargetTriple(TheModule->getTargetTriple());
566  std::unique_ptr<TargetLibraryInfoImpl> TLII(
567      createTLII(TargetTriple, CodeGenOpts));
568  PM->add(new TargetLibraryInfoWrapperPass(*TLII));
569
570  // Normal mode, emit a .s or .o file by running the code generator. Note,
571  // this also adds codegenerator level optimization passes.
572  TargetMachine::CodeGenFileType CGFT = TargetMachine::CGFT_AssemblyFile;
573  if (Action == Backend_EmitObj)
574    CGFT = TargetMachine::CGFT_ObjectFile;
575  else if (Action == Backend_EmitMCNull)
576    CGFT = TargetMachine::CGFT_Null;
577  else
578    assert(Action == Backend_EmitAssembly && "Invalid action!");
579
580  // Add ObjC ARC final-cleanup optimizations. This is done as part of the
581  // "codegen" passes so that it isn't run multiple times when there is
582  // inlining happening.
583  if (CodeGenOpts.OptimizationLevel > 0)
584    PM->add(createObjCARCContractPass());
585
586  if (TM->addPassesToEmitFile(*PM, OS, CGFT,
587                              /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
588    Diags.Report(diag::err_fe_unable_to_interface_with_target);
589    return false;
590  }
591
592  return true;
593}
594
595void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
596                                      raw_pwrite_stream *OS) {
597  TimeRegion Region(llvm::TimePassesIsEnabled ? &CodeGenerationTime : nullptr);
598
599  bool UsesCodeGen = (Action != Backend_EmitNothing &&
600                      Action != Backend_EmitBC &&
601                      Action != Backend_EmitLL);
602  if (!TM)
603    TM.reset(CreateTargetMachine(UsesCodeGen));
604
605  if (UsesCodeGen && !TM)
606    return;
607  if (TM)
608    TheModule->setDataLayout(*TM->getDataLayout());
609  CreatePasses();
610
611  switch (Action) {
612  case Backend_EmitNothing:
613    break;
614
615  case Backend_EmitBC:
616    getPerModulePasses()->add(
617        createBitcodeWriterPass(*OS, CodeGenOpts.EmitLLVMUseLists));
618    break;
619
620  case Backend_EmitLL:
621    getPerModulePasses()->add(
622        createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
623    break;
624
625  default:
626    if (!AddEmitPasses(Action, *OS))
627      return;
628  }
629
630  // Before executing passes, print the final values of the LLVM options.
631  cl::PrintOptionValues();
632
633  // Run passes. For now we do all passes at once, but eventually we
634  // would like to have the option of streaming code generation.
635
636  if (PerFunctionPasses) {
637    PrettyStackTraceString CrashInfo("Per-function optimization");
638
639    PerFunctionPasses->doInitialization();
640    for (Function &F : *TheModule)
641      if (!F.isDeclaration())
642        PerFunctionPasses->run(F);
643    PerFunctionPasses->doFinalization();
644  }
645
646  if (PerModulePasses) {
647    PrettyStackTraceString CrashInfo("Per-module optimization passes");
648    PerModulePasses->run(*TheModule);
649  }
650
651  if (CodeGenPasses) {
652    PrettyStackTraceString CrashInfo("Code generation");
653    CodeGenPasses->run(*TheModule);
654  }
655}
656
657void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
658                              const CodeGenOptions &CGOpts,
659                              const clang::TargetOptions &TOpts,
660                              const LangOptions &LOpts, StringRef TDesc,
661                              Module *M, BackendAction Action,
662                              raw_pwrite_stream *OS) {
663  EmitAssemblyHelper AsmHelper(Diags, CGOpts, TOpts, LOpts, M);
664
665  AsmHelper.EmitAssembly(Action, OS);
666
667  // If an optional clang TargetInfo description string was passed in, use it to
668  // verify the LLVM TargetMachine's DataLayout.
669  if (AsmHelper.TM && !TDesc.empty()) {
670    std::string DLDesc =
671        AsmHelper.TM->getDataLayout()->getStringRepresentation();
672    if (DLDesc != TDesc) {
673      unsigned DiagID = Diags.getCustomDiagID(
674          DiagnosticsEngine::Error, "backend data layout '%0' does not match "
675                                    "expected target description '%1'");
676      Diags.Report(DiagID) << DLDesc << TDesc;
677    }
678  }
679}
680