1 files changed, 616 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/CodeGen/BackendUtil.cpp b/contrib/llvm/tools/clang/lib/CodeGen/BackendUtil.cpp
new file mode 100644
index 0000000..90b0f68
--- /dev/null
+++ b/contrib/llvm/tools/clang/lib/CodeGen/BackendUtil.cpp
@@ -0,0 +1,616 @@
+//===--- BackendUtil.cpp - LLVM Backend Utilities -------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/CodeGen/BackendUtil.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/LangOptions.h"
+#include "clang/Basic/TargetOptions.h"
+#include "clang/Frontend/CodeGenOptions.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "llvm/Analysis/Verifier.h"
+#include "llvm/Assembly/PrintModulePass.h"
+#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/CodeGen/RegAllocRegistry.h"
+#include "llvm/CodeGen/SchedulerRegistry.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/Module.h"
+#include "llvm/MC/SubtargetFeature.h"
+#include "llvm/PassManager.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/FormattedStream.h"
+#include "llvm/Support/PrettyStackTrace.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/Timer.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetLibraryInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Transforms/IPO.h"
+#include "llvm/Transforms/IPO/PassManagerBuilder.h"
+#include "llvm/Transforms/Instrumentation.h"
+#include "llvm/Transforms/ObjCARC.h"
+#include "llvm/Transforms/Scalar.h"
+using namespace clang;
+using namespace llvm;
+
+namespace {
+
+class EmitAssemblyHelper {
+  DiagnosticsEngine &Diags;
+  const CodeGenOptions &CodeGenOpts;
+  const clang::TargetOptions &TargetOpts;
+  const LangOptions &LangOpts;
+  Module *TheModule;
+
+  Timer CodeGenerationTime;
+
+  mutable PassManager *CodeGenPasses;
+  mutable PassManager *PerModulePasses;
+  mutable FunctionPassManager *PerFunctionPasses;
+
+private:
+  PassManager *getCodeGenPasses(TargetMachine *TM) const {
+    if (!CodeGenPasses) {
+      CodeGenPasses = new PassManager();
+      CodeGenPasses->add(new DataLayout(TheModule));
+      if (TM)
+        TM->addAnalysisPasses(*CodeGenPasses);
+    }
+    return CodeGenPasses;
+  }
+
+  PassManager *getPerModulePasses(TargetMachine *TM) const {
+    if (!PerModulePasses) {
+      PerModulePasses = new PassManager();
+      PerModulePasses->add(new DataLayout(TheModule));
+      if (TM)
+        TM->addAnalysisPasses(*PerModulePasses);
+    }
+    return PerModulePasses;
+  }
+
+  FunctionPassManager *getPerFunctionPasses(TargetMachine *TM) const {
+    if (!PerFunctionPasses) {
+      PerFunctionPasses = new FunctionPassManager(TheModule);
+      PerFunctionPasses->add(new DataLayout(TheModule));
+      if (TM)
+        TM->addAnalysisPasses(*PerFunctionPasses);
+    }
+    return PerFunctionPasses;
+  }
+
+
+  void CreatePasses(TargetMachine *TM);
+
+  /// CreateTargetMachine - Generates the TargetMachine.
+  /// Returns Null if it is unable to create the target machine.
+  /// Some of our clang tests specify triples which are not built
+  /// into clang. This is okay because these tests check the generated
+  /// IR, and they require DataLayout which depends on the triple.
+  /// In this case, we allow this method to fail and not report an error.
+  /// When MustCreateTM is used, we print an error if we are unable to load
+  /// the requested target.
+  TargetMachine *CreateTargetMachine(bool MustCreateTM);
+
+  /// AddEmitPasses - Add passes necessary to emit assembly or LLVM IR.
+  ///
+  /// \return True on success.
+  bool AddEmitPasses(BackendAction Action, formatted_raw_ostream &OS,
+                     TargetMachine *TM);
+
+public:
+  EmitAssemblyHelper(DiagnosticsEngine &_Diags,
+                     const CodeGenOptions &CGOpts,
+                     const clang::TargetOptions &TOpts,
+                     const LangOptions &LOpts,
+                     Module *M)
+    : Diags(_Diags), CodeGenOpts(CGOpts), TargetOpts(TOpts), LangOpts(LOpts),
+      TheModule(M), CodeGenerationTime("Code Generation Time"),
+      CodeGenPasses(0), PerModulePasses(0), PerFunctionPasses(0) {}
+
+  ~EmitAssemblyHelper() {
+    delete CodeGenPasses;
+    delete PerModulePasses;
+    delete PerFunctionPasses;
+  }
+
+  void EmitAssembly(BackendAction Action, raw_ostream *OS);
+};
+
+// We need this wrapper to access LangOpts and CGOpts from extension functions
+// that we add to the PassManagerBuilder.
+class PassManagerBuilderWrapper : public PassManagerBuilder {
+public:
+  PassManagerBuilderWrapper(const CodeGenOptions &CGOpts,
+                            const LangOptions &LangOpts)
+      : PassManagerBuilder(), CGOpts(CGOpts), LangOpts(LangOpts) {}
+  const CodeGenOptions &getCGOpts() const { return CGOpts; }
+  const LangOptions &getLangOpts() const { return LangOpts; }
+private:
+  const CodeGenOptions &CGOpts;
+  const LangOptions &LangOpts;
+};
+
+}
+
+static void addObjCARCAPElimPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
+  if (Builder.OptLevel > 0)
+    PM.add(createObjCARCAPElimPass());
+}
+
+static void addObjCARCExpandPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
+  if (Builder.OptLevel > 0)
+    PM.add(createObjCARCExpandPass());
+}
+
+static void addObjCARCOptPass(const PassManagerBuilder &Builder, PassManagerBase &PM) {
+  if (Builder.OptLevel > 0)
+    PM.add(createObjCARCOptPass());
+}
+
+static void addSampleProfileLoaderPass(const PassManagerBuilder &Builder,
+                                       PassManagerBase &PM) {
+  const PassManagerBuilderWrapper &BuilderWrapper =
+      static_cast<const PassManagerBuilderWrapper &>(Builder);
+  const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
+  PM.add(createSampleProfileLoaderPass(CGOpts.SampleProfileFile));
+}
+
+static void addBoundsCheckingPass(const PassManagerBuilder &Builder,
+                                    PassManagerBase &PM) {
+  PM.add(createBoundsCheckingPass());
+}
+
+static void addAddressSanitizerPasses(const PassManagerBuilder &Builder,
+                                      PassManagerBase &PM) {
+  const PassManagerBuilderWrapper &BuilderWrapper =
+      static_cast<const PassManagerBuilderWrapper&>(Builder);
+  const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
+  const LangOptions &LangOpts = BuilderWrapper.getLangOpts();
+  PM.add(createAddressSanitizerFunctionPass(
+      LangOpts.Sanitize.InitOrder,
+      LangOpts.Sanitize.UseAfterReturn,
+      LangOpts.Sanitize.UseAfterScope,
+      CGOpts.SanitizerBlacklistFile,
+      CGOpts.SanitizeAddressZeroBaseShadow));
+  PM.add(createAddressSanitizerModulePass(
+      LangOpts.Sanitize.InitOrder,
+      CGOpts.SanitizerBlacklistFile,
+      CGOpts.SanitizeAddressZeroBaseShadow));
+}
+
+static void addMemorySanitizerPass(const PassManagerBuilder &Builder,
+                                   PassManagerBase &PM) {
+  const PassManagerBuilderWrapper &BuilderWrapper =
+      static_cast<const PassManagerBuilderWrapper&>(Builder);
+  const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
+  PM.add(createMemorySanitizerPass(CGOpts.SanitizeMemoryTrackOrigins,
+                                   CGOpts.SanitizerBlacklistFile));
+
+  // MemorySanitizer inserts complex instrumentation that mostly follows
+  // the logic of the original code, but operates on "shadow" values.
+  // It can benefit from re-running some general purpose optimization passes.
+  if (Builder.OptLevel > 0) {
+    PM.add(createEarlyCSEPass());
+    PM.add(createReassociatePass());
+    PM.add(createLICMPass());
+    PM.add(createGVNPass());
+    PM.add(createInstructionCombiningPass());
+    PM.add(createDeadStoreEliminationPass());
+  }
+}
+
+static void addThreadSanitizerPass(const PassManagerBuilder &Builder,
+                                   PassManagerBase &PM) {
+  const PassManagerBuilderWrapper &BuilderWrapper =
+      static_cast<const PassManagerBuilderWrapper&>(Builder);
+  const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
+  PM.add(createThreadSanitizerPass(CGOpts.SanitizerBlacklistFile));
+}
+
+static void addDataFlowSanitizerPass(const PassManagerBuilder &Builder,
+                                     PassManagerBase &PM) {
+  const PassManagerBuilderWrapper &BuilderWrapper =
+      static_cast<const PassManagerBuilderWrapper&>(Builder);
+  const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
+  PM.add(createDataFlowSanitizerPass(CGOpts.SanitizerBlacklistFile));
+}
+
+void EmitAssemblyHelper::CreatePasses(TargetMachine *TM) {
+  unsigned OptLevel = CodeGenOpts.OptimizationLevel;
+  CodeGenOptions::InliningMethod Inlining = CodeGenOpts.getInlining();
+
+  // Handle disabling of LLVM optimization, where we want to preserve the
+  // internal module before any optimization.
+  if (CodeGenOpts.DisableLLVMOpts) {
+    OptLevel = 0;
+    Inlining = CodeGenOpts.NoInlining;
+  }
+
+  PassManagerBuilderWrapper PMBuilder(CodeGenOpts, LangOpts);
+  PMBuilder.OptLevel = OptLevel;
+  PMBuilder.SizeLevel = CodeGenOpts.OptimizeSize;
+  PMBuilder.BBVectorize = CodeGenOpts.VectorizeBB;
+  PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
+  PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
+
+  PMBuilder.DisableUnitAtATime = !CodeGenOpts.UnitAtATime;
+  PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
+  PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
+
+  if (!CodeGenOpts.SampleProfileFile.empty())
+    PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
+                           addSampleProfileLoaderPass);
+
+  // In ObjC ARC mode, add the main ARC optimization passes.
+  if (LangOpts.ObjCAutoRefCount) {
+    PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,
+                           addObjCARCExpandPass);
+    PMBuilder.addExtension(PassManagerBuilder::EP_ModuleOptimizerEarly,
+                           addObjCARCAPElimPass);
+    PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
+                           addObjCARCOptPass);
+  }
+
+  if (LangOpts.Sanitize.LocalBounds) {
+    PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
+                           addBoundsCheckingPass);
+    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
+                           addBoundsCheckingPass);
+  }
+
+  if (LangOpts.Sanitize.Address) {
+    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
+                           addAddressSanitizerPasses);
+    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
+                           addAddressSanitizerPasses);
+  }
+
+  if (LangOpts.Sanitize.Memory) {
+    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
+                           addMemorySanitizerPass);
+    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
+                           addMemorySanitizerPass);
+  }
+
+  if (LangOpts.Sanitize.Thread) {
+    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
+                           addThreadSanitizerPass);
+    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
+                           addThreadSanitizerPass);
+  }
+
+  if (LangOpts.Sanitize.DataFlow) {
+    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
+                           addDataFlowSanitizerPass);
+    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
+                           addDataFlowSanitizerPass);
+  }
+
+  // Figure out TargetLibraryInfo.
+  Triple TargetTriple(TheModule->getTargetTriple());
+  PMBuilder.LibraryInfo = new TargetLibraryInfo(TargetTriple);
+  if (!CodeGenOpts.SimplifyLibCalls)
+    PMBuilder.LibraryInfo->disableAllFunctions();
+  
+  switch (Inlining) {
+  case CodeGenOptions::NoInlining: break;
+  case CodeGenOptions::NormalInlining: {
+    // FIXME: Derive these constants in a principled fashion.
+    unsigned Threshold = 225;
+    if (CodeGenOpts.OptimizeSize == 1)      // -Os
+      Threshold = 75;
+    else if (CodeGenOpts.OptimizeSize == 2) // -Oz
+      Threshold = 25;
+    else if (OptLevel > 2)
+      Threshold = 275;
+    PMBuilder.Inliner = createFunctionInliningPass(Threshold);
+    break;
+  }
+  case CodeGenOptions::OnlyAlwaysInlining:
+    // Respect always_inline.
+    if (OptLevel == 0)
+      // Do not insert lifetime intrinsics at -O0.
+      PMBuilder.Inliner = createAlwaysInlinerPass(false);
+    else
+      PMBuilder.Inliner = createAlwaysInlinerPass();
+    break;
+  }
+
+  // Set up the per-function pass manager.
+  FunctionPassManager *FPM = getPerFunctionPasses(TM);
+  if (CodeGenOpts.VerifyModule)
+    FPM->add(createVerifierPass());
+  PMBuilder.populateFunctionPassManager(*FPM);
+
+  // Set up the per-module pass manager.
+  PassManager *MPM = getPerModulePasses(TM);
+
+  if (!CodeGenOpts.DisableGCov &&
+      (CodeGenOpts.EmitGcovArcs || CodeGenOpts.EmitGcovNotes)) {
+    // Not using 'GCOVOptions::getDefault' allows us to avoid exiting if
+    // LLVM's -default-gcov-version flag is set to something invalid.
+    GCOVOptions Options;
+    Options.EmitNotes = CodeGenOpts.EmitGcovNotes;
+    Options.EmitData = CodeGenOpts.EmitGcovArcs;
+    memcpy(Options.Version, CodeGenOpts.CoverageVersion, 4);
+    Options.UseCfgChecksum = CodeGenOpts.CoverageExtraChecksum;
+    Options.NoRedZone = CodeGenOpts.DisableRedZone;
+    Options.FunctionNamesInData =
+        !CodeGenOpts.CoverageNoFunctionNamesInData;
+    MPM->add(createGCOVProfilerPass(Options));
+    if (CodeGenOpts.getDebugInfo() == CodeGenOptions::NoDebugInfo)
+      MPM->add(createStripSymbolsPass(true));
+  }
+
+  PMBuilder.populateModulePassManager(*MPM);
+}
+
+TargetMachine *EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
+  // Create the TargetMachine for generating code.
+  std::string Error;
+  std::string Triple = TheModule->getTargetTriple();
+  const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
+  if (!TheTarget) {
+    if (MustCreateTM)
+      Diags.Report(diag::err_fe_unable_to_create_target) << Error;
+    return 0;
+  }
+
+  // FIXME: Expose these capabilities via actual APIs!!!! Aside from just
+  // being gross, this is also totally broken if we ever care about
+  // concurrency.
+
+  TargetMachine::setAsmVerbosityDefault(CodeGenOpts.AsmVerbose);
+
+  TargetMachine::setFunctionSections(CodeGenOpts.FunctionSections);
+  TargetMachine::setDataSections    (CodeGenOpts.DataSections);
+
+  // FIXME: Parse this earlier.
+  llvm::CodeModel::Model CM;
+  if (CodeGenOpts.CodeModel == "small") {
+    CM = llvm::CodeModel::Small;
+  } else if (CodeGenOpts.CodeModel == "kernel") {
+    CM = llvm::CodeModel::Kernel;
+  } else if (CodeGenOpts.CodeModel == "medium") {
+    CM = llvm::CodeModel::Medium;
+  } else if (CodeGenOpts.CodeModel == "large") {
+    CM = llvm::CodeModel::Large;
+  } else {
+    assert(CodeGenOpts.CodeModel.empty() && "Invalid code model!");
+    CM = llvm::CodeModel::Default;
+  }
+
+  SmallVector<const char *, 16> BackendArgs;
+  BackendArgs.push_back("clang"); // Fake program name.
+  if (!CodeGenOpts.DebugPass.empty()) {
+    BackendArgs.push_back("-debug-pass");
+    BackendArgs.push_back(CodeGenOpts.DebugPass.c_str());
+  }
+  if (!CodeGenOpts.LimitFloatPrecision.empty()) {
+    BackendArgs.push_back("-limit-float-precision");
+    BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str());
+  }
+  if (llvm::TimePassesIsEnabled)
+    BackendArgs.push_back("-time-passes");
+  for (unsigned i = 0, e = CodeGenOpts.BackendOptions.size(); i != e; ++i)
+    BackendArgs.push_back(CodeGenOpts.BackendOptions[i].c_str());
+  if (CodeGenOpts.NoGlobalMerge)
+    BackendArgs.push_back("-global-merge=false");
+  BackendArgs.push_back(0);
+  llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1,
+                                    BackendArgs.data());
+
+  std::string FeaturesStr;
+  if (TargetOpts.Features.size()) {
+    SubtargetFeatures Features;
+    for (std::vector<std::string>::const_iterator
+           it = TargetOpts.Features.begin(),
+           ie = TargetOpts.Features.end(); it != ie; ++it)
+      Features.AddFeature(*it);
+    FeaturesStr = Features.getString();
+  }
+
+  llvm::Reloc::Model RM = llvm::Reloc::Default;
+  if (CodeGenOpts.RelocationModel == "static") {
+    RM = llvm::Reloc::Static;
+  } else if (CodeGenOpts.RelocationModel == "pic") {
+    RM = llvm::Reloc::PIC_;
+  } else {
+    assert(CodeGenOpts.RelocationModel == "dynamic-no-pic" &&
+           "Invalid PIC model!");
+    RM = llvm::Reloc::DynamicNoPIC;
+  }
+
+  CodeGenOpt::Level OptLevel = CodeGenOpt::Default;
+  switch (CodeGenOpts.OptimizationLevel) {
+  default: break;
+  case 0: OptLevel = CodeGenOpt::None; break;
+  case 3: OptLevel = CodeGenOpt::Aggressive; break;
+  }
+
+  llvm::TargetOptions Options;
+
+  // Set frame pointer elimination mode.
+  if (!CodeGenOpts.DisableFPElim) {
+    Options.NoFramePointerElim = false;
+  } else if (CodeGenOpts.OmitLeafFramePointer) {
+    Options.NoFramePointerElim = false;
+  } else {
+    Options.NoFramePointerElim = true;
+  }
+
+  if (CodeGenOpts.UseInitArray)
+    Options.UseInitArray = true;
+
+  // Set float ABI type.
+  if (CodeGenOpts.FloatABI == "soft" || CodeGenOpts.FloatABI == "softfp")
+    Options.FloatABIType = llvm::FloatABI::Soft;
+  else if (CodeGenOpts.FloatABI == "hard")
+    Options.FloatABIType = llvm::FloatABI::Hard;
+  else {
+    assert(CodeGenOpts.FloatABI.empty() && "Invalid float abi!");
+    Options.FloatABIType = llvm::FloatABI::Default;
+  }
+
+  // Set FP fusion mode.
+  switch (CodeGenOpts.getFPContractMode()) {
+  case CodeGenOptions::FPC_Off:
+    Options.AllowFPOpFusion = llvm::FPOpFusion::Strict;
+    break;
+  case CodeGenOptions::FPC_On:
+    Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
+    break;
+  case CodeGenOptions::FPC_Fast:
+    Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
+    break;
+  }
+
+  Options.LessPreciseFPMADOption = CodeGenOpts.LessPreciseFPMAD;
+  Options.NoInfsFPMath = CodeGenOpts.NoInfsFPMath;
+  Options.NoNaNsFPMath = CodeGenOpts.NoNaNsFPMath;
+  Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
+  Options.UnsafeFPMath = CodeGenOpts.UnsafeFPMath;
+  Options.UseSoftFloat = CodeGenOpts.SoftFloat;
+  Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
+  Options.DisableTailCalls = CodeGenOpts.DisableTailCalls;
+  Options.TrapFuncName = CodeGenOpts.TrapFuncName;
+  Options.PositionIndependentExecutable = LangOpts.PIELevel != 0;
+  Options.EnableSegmentedStacks = CodeGenOpts.EnableSegmentedStacks;
+
+  TargetMachine *TM = TheTarget->createTargetMachine(Triple, TargetOpts.CPU,
+                                                     FeaturesStr, Options,
+                                                     RM, CM, OptLevel);
+
+  if (CodeGenOpts.RelaxAll)
+    TM->setMCRelaxAll(true);
+  if (CodeGenOpts.SaveTempLabels)
+    TM->setMCSaveTempLabels(true);
+  if (CodeGenOpts.NoDwarf2CFIAsm)
+    TM->setMCUseCFI(false);
+  if (!CodeGenOpts.NoDwarfDirectoryAsm)
+    TM->setMCUseDwarfDirectory(true);
+  if (CodeGenOpts.NoExecStack)
+    TM->setMCNoExecStack(true);
+
+  return TM;
+}
+
+bool EmitAssemblyHelper::AddEmitPasses(BackendAction Action,
+                                       formatted_raw_ostream &OS,
+                                       TargetMachine *TM) {
+
+  // Create the code generator passes.
+  PassManager *PM = getCodeGenPasses(TM);
+
+  // Add LibraryInfo.
+  llvm::Triple TargetTriple(TheModule->getTargetTriple());
+  TargetLibraryInfo *TLI = new TargetLibraryInfo(TargetTriple);
+  if (!CodeGenOpts.SimplifyLibCalls)
+    TLI->disableAllFunctions();
+  PM->add(TLI);
+
+  // Add Target specific analysis passes.
+  TM->addAnalysisPasses(*PM);
+
+  // Normal mode, emit a .s or .o file by running the code generator. Note,
+  // this also adds codegenerator level optimization passes.
+  TargetMachine::CodeGenFileType CGFT = TargetMachine::CGFT_AssemblyFile;
+  if (Action == Backend_EmitObj)
+    CGFT = TargetMachine::CGFT_ObjectFile;
+  else if (Action == Backend_EmitMCNull)
+    CGFT = TargetMachine::CGFT_Null;
+  else
+    assert(Action == Backend_EmitAssembly && "Invalid action!");
+
+  // Add ObjC ARC final-cleanup optimizations. This is done as part of the
+  // "codegen" passes so that it isn't run multiple times when there is
+  // inlining happening.
+  if (LangOpts.ObjCAutoRefCount &&
+      CodeGenOpts.OptimizationLevel > 0)
+    PM->add(createObjCARCContractPass());
+
+  if (TM->addPassesToEmitFile(*PM, OS, CGFT,
+                              /*DisableVerify=*/!CodeGenOpts.VerifyModule)) {
+    Diags.Report(diag::err_fe_unable_to_interface_with_target);
+    return false;
+  }
+
+  return true;
+}
+
+void EmitAssemblyHelper::EmitAssembly(BackendAction Action, raw_ostream *OS) {
+  TimeRegion Region(llvm::TimePassesIsEnabled ? &CodeGenerationTime : 0);
+  llvm::formatted_raw_ostream FormattedOS;
+
+  bool UsesCodeGen = (Action != Backend_EmitNothing &&
+                      Action != Backend_EmitBC &&
+                      Action != Backend_EmitLL);
+  TargetMachine *TM = CreateTargetMachine(UsesCodeGen);
+  if (UsesCodeGen && !TM) return;
+  llvm::OwningPtr<TargetMachine> TMOwner(CodeGenOpts.DisableFree ? 0 : TM);
+  CreatePasses(TM);
+
+  switch (Action) {
+  case Backend_EmitNothing:
+    break;
+
+  case Backend_EmitBC:
+    getPerModulePasses(TM)->add(createBitcodeWriterPass(*OS));
+    break;
+
+  case Backend_EmitLL:
+    FormattedOS.setStream(*OS, formatted_raw_ostream::PRESERVE_STREAM);
+    getPerModulePasses(TM)->add(createPrintModulePass(&FormattedOS));
+    break;
+
+  default:
+    FormattedOS.setStream(*OS, formatted_raw_ostream::PRESERVE_STREAM);
+    if (!AddEmitPasses(Action, FormattedOS, TM))
+      return;
+  }
+
+  // Before executing passes, print the final values of the LLVM options.
+  cl::PrintOptionValues();
+
+  // Run passes. For now we do all passes at once, but eventually we
+  // would like to have the option of streaming code generation.
+
+  if (PerFunctionPasses) {
+    PrettyStackTraceString CrashInfo("Per-function optimization");
+
+    PerFunctionPasses->doInitialization();
+    for (Module::iterator I = TheModule->begin(),
+           E = TheModule->end(); I != E; ++I)
+      if (!I->isDeclaration())
+        PerFunctionPasses->run(*I);
+    PerFunctionPasses->doFinalization();
+  }
+
+  if (PerModulePasses) {
+    PrettyStackTraceString CrashInfo("Per-module optimization passes");
+    PerModulePasses->run(*TheModule);
+  }
+
+  if (CodeGenPasses) {
+    PrettyStackTraceString CrashInfo("Code generation");
+    CodeGenPasses->run(*TheModule);
+  }
+}
+
+void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
+                              const CodeGenOptions &CGOpts,
+                              const clang::TargetOptions &TOpts,
+                              const LangOptions &LOpts,
+                              Module *M,
+                              BackendAction Action, raw_ostream *OS) {
+  EmitAssemblyHelper AsmHelper(Diags, CGOpts, TOpts, LOpts, M);
+
+  AsmHelper.EmitAssembly(Action, OS);
+}