C++ ArrayRef类代码示例

/// Look through operations that will be free to find the earliest source of
/// this value.
///
/// @param ValLoc If V has aggegate type, we will be interested in a particular
/// scalar component. This records its address; the reverse of this list gives a
/// sequence of indices appropriate for an extractvalue to locate the important
/// value. This value is updated during the function and on exit will indicate
/// similar information for the Value returned.
///
/// @param DataBits If this function looks through truncate instructions, this
/// will record the smallest size attained.
static const Value *getNoopInput(const Value *V,
                                 SmallVectorImpl<unsigned> &ValLoc,
                                 unsigned &DataBits,
                                 const TargetLoweringBase &TLI) {
  while (true) {
    // Try to look through V1; if V1 is not an instruction, it can't be looked
    // through.
    const Instruction *I = dyn_cast<Instruction>(V);
    if (!I || I->getNumOperands() == 0) return V;
    const Value *NoopInput = nullptr;

    Value *Op = I->getOperand(0);
    if (isa<BitCastInst>(I)) {
      // Look through truly no-op bitcasts.
      if (isNoopBitcast(Op->getType(), I->getType(), TLI))
        NoopInput = Op;
    } else if (isa<GetElementPtrInst>(I)) {
      // Look through getelementptr
      if (cast<GetElementPtrInst>(I)->hasAllZeroIndices())
        NoopInput = Op;
    } else if (isa<IntToPtrInst>(I)) {
      // Look through inttoptr.
      // Make sure this isn't a truncating or extending cast.  We could
      // support this eventually, but don't bother for now.
      if (!isa<VectorType>(I->getType()) &&
          TLI.getPointerTy().getSizeInBits() ==
          cast<IntegerType>(Op->getType())->getBitWidth())
        NoopInput = Op;
    } else if (isa<PtrToIntInst>(I)) {
      // Look through ptrtoint.
      // Make sure this isn't a truncating or extending cast.  We could
      // support this eventually, but don't bother for now.
      if (!isa<VectorType>(I->getType()) &&
          TLI.getPointerTy().getSizeInBits() ==
          cast<IntegerType>(I->getType())->getBitWidth())
        NoopInput = Op;
    } else if (isa<TruncInst>(I) &&
               TLI.allowTruncateForTailCall(Op->getType(), I->getType())) {
      DataBits = std::min(DataBits, I->getType()->getPrimitiveSizeInBits());
      NoopInput = Op;
    } else if (isa<CallInst>(I)) {
      // Look through call (skipping callee)
      for (User::const_op_iterator i = I->op_begin(), e = I->op_end() - 1;
           i != e; ++i) {
        unsigned attrInd = i - I->op_begin() + 1;
        if (cast<CallInst>(I)->paramHasAttr(attrInd, Attribute::Returned) &&
            isNoopBitcast((*i)->getType(), I->getType(), TLI)) {
          NoopInput = *i;
          break;
        }
      }
    } else if (isa<InvokeInst>(I)) {
      // Look through invoke (skipping BB, BB, Callee)
      for (User::const_op_iterator i = I->op_begin(), e = I->op_end() - 3;
           i != e; ++i) {
        unsigned attrInd = i - I->op_begin() + 1;
        if (cast<InvokeInst>(I)->paramHasAttr(attrInd, Attribute::Returned) &&
            isNoopBitcast((*i)->getType(), I->getType(), TLI)) {
          NoopInput = *i;
          break;
        }
      }
    } else if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(V)) {
      // Value may come from either the aggregate or the scalar
      ArrayRef<unsigned> InsertLoc = IVI->getIndices();
      if (std::equal(InsertLoc.rbegin(), InsertLoc.rend(),
                     ValLoc.rbegin())) {
        // The type being inserted is a nested sub-type of the aggregate; we
        // have to remove those initial indices to get the location we're
        // interested in for the operand.
        ValLoc.resize(ValLoc.size() - InsertLoc.size());
        NoopInput = IVI->getInsertedValueOperand();
      } else {
        // The struct we're inserting into has the value we're interested in, no
        // change of address.
        NoopInput = Op;
      }
    } else if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(V)) {
      // The part we're interested in will inevitably be some sub-section of the
      // previous aggregate. Combine the two paths to obtain the true address of
      // our element.
      ArrayRef<unsigned> ExtractLoc = EVI->getIndices();
      std::copy(ExtractLoc.rbegin(), ExtractLoc.rend(),
                std::back_inserter(ValLoc));
      NoopInput = Op;
    }
    // Terminate if we couldn't find anything to look through.
    if (!NoopInput)
      return V;
//.........这里部分代码省略.........

/// \brief Convenient wrapper for checking membership in RegisterOperands.
/// (std::count() doesn't have an early exit).
static bool containsReg(ArrayRef<unsigned> RegUnits, unsigned RegUnit) {
  return std::find(RegUnits.begin(), RegUnits.end(), RegUnit) != RegUnits.end();
}

/// Simply decrease the current pressure as impacted by these registers.
void RegPressureTracker::decreaseRegPressure(ArrayRef<unsigned> RegUnits) {
  for (unsigned I = 0, E = RegUnits.size(); I != E; ++I)
    decreaseSetPressure(CurrSetPressure, MRI->getPressureSets(RegUnits[I]));
}

/// emitModuleFlags - Perform code emission for module flags.
void TargetLoweringObjectFileMachO::
emitModuleFlags(MCStreamer &Streamer,
                ArrayRef<Module::ModuleFlagEntry> ModuleFlags,
                Mangler &Mang, const TargetMachine &TM) const {
  unsigned VersionVal = 0;
  unsigned ImageInfoFlags = 0;
  MDNode *LinkerOptions = nullptr;
  StringRef SectionVal;

  for (ArrayRef<Module::ModuleFlagEntry>::iterator
         i = ModuleFlags.begin(), e = ModuleFlags.end(); i != e; ++i) {
    const Module::ModuleFlagEntry &MFE = *i;

    // Ignore flags with 'Require' behavior.
    if (MFE.Behavior == Module::Require)
      continue;

    StringRef Key = MFE.Key->getString();
    Metadata *Val = MFE.Val;

    if (Key == "Objective-C Image Info Version") {
      VersionVal = mdconst::extract<ConstantInt>(Val)->getZExtValue();
    } else if (Key == "Objective-C Garbage Collection" ||
               Key == "Objective-C GC Only" ||
               Key == "Objective-C Is Simulated" ||
               Key == "Objective-C Image Swift Version") {
      ImageInfoFlags |= mdconst::extract<ConstantInt>(Val)->getZExtValue();
    } else if (Key == "Objective-C Image Info Section") {
      SectionVal = cast<MDString>(Val)->getString();
    } else if (Key == "Linker Options") {
      LinkerOptions = cast<MDNode>(Val);
    }
  }

  // Emit the linker options if present.
  if (LinkerOptions) {
    for (unsigned i = 0, e = LinkerOptions->getNumOperands(); i != e; ++i) {
      MDNode *MDOptions = cast<MDNode>(LinkerOptions->getOperand(i));
      SmallVector<std::string, 4> StrOptions;

      // Convert to strings.
      for (unsigned ii = 0, ie = MDOptions->getNumOperands(); ii != ie; ++ii) {
        MDString *MDOption = cast<MDString>(MDOptions->getOperand(ii));
        StrOptions.push_back(MDOption->getString());
      }

      Streamer.EmitLinkerOptions(StrOptions);
    }
  }

  // The section is mandatory. If we don't have it, then we don't have GC info.
  if (SectionVal.empty()) return;

  StringRef Segment, Section;
  unsigned TAA = 0, StubSize = 0;
  bool TAAParsed;
  std::string ErrorCode =
    MCSectionMachO::ParseSectionSpecifier(SectionVal, Segment, Section,
                                          TAA, TAAParsed, StubSize);
  if (!ErrorCode.empty())
    // If invalid, report the error with report_fatal_error.
    report_fatal_error("Invalid section specifier '" + Section + "': " +
                       ErrorCode + ".");

  // Get the section.
  const MCSectionMachO *S =
    getContext().getMachOSection(Segment, Section, TAA, StubSize,
                                 SectionKind::getDataNoRel());
  Streamer.SwitchSection(S);
  Streamer.EmitLabel(getContext().
                     GetOrCreateSymbol(StringRef("L_OBJC_IMAGE_INFO")));
  Streamer.EmitIntValue(VersionVal, 4);
  Streamer.EmitIntValue(ImageInfoFlags, 4);
  Streamer.AddBlankLine();
}

void APValue::printPretty(raw_ostream &Out, ASTContext &Ctx, QualType Ty) const{
  switch (getKind()) {
  case APValue::Uninitialized:
    Out << "<uninitialized>";
    return;
  case APValue::Int:
    if (Ty->isBooleanType())
      Out << (getInt().getBoolValue() ? "true" : "false");
    else
      Out << getInt();
    return;
  case APValue::Float:
    Out << GetApproxValue(getFloat());
    return;
  case APValue::Vector: {
    Out << '{';
    QualType ElemTy = Ty->getAs<VectorType>()->getElementType();
    getVectorElt(0).printPretty(Out, Ctx, ElemTy);
    for (unsigned i = 1; i != getVectorLength(); ++i) {
      Out << ", ";
      getVectorElt(i).printPretty(Out, Ctx, ElemTy);
    }
    Out << '}';
    return;
  }
  case APValue::ComplexInt:
    Out << getComplexIntReal() << "+" << getComplexIntImag() << "i";
    return;
  case APValue::ComplexFloat:
    Out << GetApproxValue(getComplexFloatReal()) << "+"
        << GetApproxValue(getComplexFloatImag()) << "i";
    return;
  case APValue::LValue: {
    LValueBase Base = getLValueBase();
    if (!Base) {
      Out << "0";
      return;
    }

    bool IsReference = Ty->isReferenceType();
    QualType InnerTy
      = IsReference ? Ty.getNonReferenceType() : Ty->getPointeeType();

    if (!hasLValuePath()) {
      // No lvalue path: just print the offset.
      CharUnits O = getLValueOffset();
      CharUnits S = Ctx.getTypeSizeInChars(InnerTy);
      if (!O.isZero()) {
        if (IsReference)
          Out << "*(";
        if (O % S) {
          Out << "(char*)";
          S = CharUnits::One();
        }
        Out << '&';
      } else if (!IsReference)
        Out << '&';

      if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>())
        Out << *VD;
      else
        Base.get<const Expr*>()->printPretty(Out, 0, Ctx.getPrintingPolicy());
      if (!O.isZero()) {
        Out << " + " << (O / S);
        if (IsReference)
          Out << ')';
      }
      return;
    }

    // We have an lvalue path. Print it out nicely.
    if (!IsReference)
      Out << '&';
    else if (isLValueOnePastTheEnd())
      Out << "*(&";

    QualType ElemTy;
    if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>()) {
      Out << *VD;
      ElemTy = VD->getType();
    } else {
      const Expr *E = Base.get<const Expr*>();
      E->printPretty(Out, 0, Ctx.getPrintingPolicy());
      ElemTy = E->getType();
    }

    ArrayRef<LValuePathEntry> Path = getLValuePath();
    const CXXRecordDecl *CastToBase = 0;
    for (unsigned I = 0, N = Path.size(); I != N; ++I) {
      if (ElemTy->getAs<RecordType>()) {
        // The lvalue refers to a class type, so the next path entry is a base
        // or member.
        const Decl *BaseOrMember =
        BaseOrMemberType::getFromOpaqueValue(Path[I].BaseOrMember).getPointer();
        if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(BaseOrMember)) {
          CastToBase = RD;
          ElemTy = Ctx.getRecordType(RD);
        } else {
          const ValueDecl *VD = cast<ValueDecl>(BaseOrMember);
          Out << ".";
//.........这里部分代码省略.........

/// Performs the compile requested by the user.
/// \param Instance Will be reset after performIRGeneration when the verifier
///                 mode is NoVerify and there were no errors.
/// \returns true on error
static bool performCompile(std::unique_ptr<CompilerInstance> &Instance,
                           CompilerInvocation &Invocation,
                           ArrayRef<const char *> Args,
                           int &ReturnValue,
                           FrontendObserver *observer) {
  FrontendOptions opts = Invocation.getFrontendOptions();
  FrontendOptions::ActionType Action = opts.RequestedAction;

  // We've been asked to precompile a bridging header; we want to
  // avoid touching any other inputs and just parse, emit and exit.
  if (Action == FrontendOptions::EmitPCH) {
    auto clangImporter = static_cast<ClangImporter *>(
      Instance->getASTContext().getClangModuleLoader());
    return clangImporter->emitBridgingPCH(
      Invocation.getInputFilenames()[0], opts.getSingleOutputFilename());
  }

  IRGenOptions &IRGenOpts = Invocation.getIRGenOptions();

  bool inputIsLLVMIr = Invocation.getInputKind() == InputFileKind::IFK_LLVM_IR;
  if (inputIsLLVMIr) {
    auto &LLVMContext = getGlobalLLVMContext();

    // Load in bitcode file.
    assert(Invocation.getInputFilenames().size() == 1 &&
           "We expect a single input for bitcode input!");
    llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> FileBufOrErr =
      llvm::MemoryBuffer::getFileOrSTDIN(Invocation.getInputFilenames()[0]);
    if (!FileBufOrErr) {
      Instance->getASTContext().Diags.diagnose(SourceLoc(),
                                              diag::error_open_input_file,
                                              Invocation.getInputFilenames()[0],
                                              FileBufOrErr.getError().message());
      return true;
    }
    llvm::MemoryBuffer *MainFile = FileBufOrErr.get().get();

    llvm::SMDiagnostic Err;
    std::unique_ptr<llvm::Module> Module = llvm::parseIR(
                                             MainFile->getMemBufferRef(),
                                             Err, LLVMContext);
    if (!Module) {
      // TODO: Translate from the diagnostic info to the SourceManager location
      // if available.
      Instance->getASTContext().Diags.diagnose(SourceLoc(),
                                              diag::error_parse_input_file,
                                              Invocation.getInputFilenames()[0],
                                              Err.getMessage());
      return true;
    }

    // TODO: remove once the frontend understands what action it should perform
    IRGenOpts.OutputKind = getOutputKind(Action);

    return performLLVM(IRGenOpts, Instance->getASTContext(), Module.get());
  }

  ReferencedNameTracker nameTracker;
  bool shouldTrackReferences = !opts.ReferenceDependenciesFilePath.empty();
  if (shouldTrackReferences)
    Instance->setReferencedNameTracker(&nameTracker);

  if (Action == FrontendOptions::Parse ||
      Action == FrontendOptions::DumpParse ||
      Action == FrontendOptions::DumpInterfaceHash)
    Instance->performParseOnly();
  else
    Instance->performSema();

  if (Action == FrontendOptions::Parse)
    return Instance->getASTContext().hadError();

  if (observer) {
    observer->performedSemanticAnalysis(*Instance);
  }

  FrontendOptions::DebugCrashMode CrashMode = opts.CrashMode;
  if (CrashMode == FrontendOptions::DebugCrashMode::AssertAfterParse)
    debugFailWithAssertion();
  else if (CrashMode == FrontendOptions::DebugCrashMode::CrashAfterParse)
    debugFailWithCrash();

  ASTContext &Context = Instance->getASTContext();

  if (Action == FrontendOptions::REPL) {
    runREPL(*Instance, ProcessCmdLine(Args.begin(), Args.end()),
            Invocation.getParseStdlib());
    return Context.hadError();
  }

  SourceFile *PrimarySourceFile = Instance->getPrimarySourceFile();

  // We've been told to dump the AST (either after parsing or type-checking,
  // which is already differentiated in CompilerInstance::performSema()),
  // so dump or print the main source file and return.
  if (Action == FrontendOptions::DumpParse ||
//.........这里部分代码省略.........

void MaterializeForSetEmitter::emit(SILGenFunction &gen, ManagedValue self,
                                    SILValue resultBuffer,
                                    SILValue callbackBuffer,
                                    ArrayRef<ManagedValue> indices) {
  SILLocation loc = Witness;
  loc.markAutoGenerated();

  // If there's an abstraction difference, we always need to use the
  // get/set pattern.
  AccessStrategy strategy;
  if (WitnessStorage->getType()->is<ReferenceStorageType>() ||
      (Conformance && RequirementStorageType != WitnessStorageType)) {
    strategy = AccessStrategy::DispatchToAccessor;
  } else {
    strategy = WitnessStorage->getAccessStrategy(TheAccessSemantics,
                                                 AccessKind::ReadWrite);
  }

  // Handle the indices.
  RValue indicesRV;
  if (isa<SubscriptDecl>(WitnessStorage)) {
    indicesRV = collectIndicesFromParameters(gen, loc, indices);
  } else {
    assert(indices.empty() && "indices for a non-subscript?");
  }

  // As above, assume that we don't need to reabstract 'self'.

  // Choose the right implementation.
  SILValue address;
  SILFunction *callbackFn = nullptr;
  switch (strategy) {
  case AccessStrategy::Storage:
    address = emitUsingStorage(gen, loc, self, std::move(indicesRV));
    break;

  case AccessStrategy::Addressor:
    address = emitUsingAddressor(gen, loc, self, std::move(indicesRV),
                                 callbackBuffer, callbackFn);
    break;

  case AccessStrategy::DirectToAccessor:
  case AccessStrategy::DispatchToAccessor:
    address = emitUsingGetterSetter(gen, loc, self, std::move(indicesRV),
                                    resultBuffer, callbackBuffer, callbackFn);
    break;
  }

  // Return the address as a Builtin.RawPointer.
  SILType rawPointerTy = SILType::getRawPointerType(gen.getASTContext());
  address = gen.B.createAddressToPointer(loc, address, rawPointerTy);

  SILType resultTupleTy = gen.F.mapTypeIntoContext(
                 gen.F.getLoweredFunctionType()->getSILResult());
  SILType optCallbackTy = resultTupleTy.getTupleElementType(1);

  // Form the callback.
  SILValue callback;
  if (callbackFn) {
    // Make a reference to the function.
    callback = gen.B.createFunctionRef(loc, callbackFn);

    // If it's polymorphic, cast to RawPointer and then back to the
    // right monomorphic type.  The safety of this cast relies on some
    // assumptions about what exactly IRGen can reconstruct from the
    // callback's thick type argument.
    if (callbackFn->getLoweredFunctionType()->isPolymorphic()) {
      callback = gen.B.createThinFunctionToPointer(loc, callback, rawPointerTy);

      OptionalTypeKind optKind;
      auto callbackTy = optCallbackTy.getAnyOptionalObjectType(SGM.M, optKind);
      callback = gen.B.createPointerToThinFunction(loc, callback, callbackTy);
    }

    callback = gen.B.createOptionalSome(loc, callback, optCallbackTy);
  } else {
    callback = gen.B.createOptionalNone(loc, optCallbackTy);
  }

  // Form the result and return.
  auto result = gen.B.createTuple(loc, resultTupleTy, { address, callback });
  gen.Cleanups.emitCleanupsForReturn(CleanupLocation::get(loc));
  gen.B.createReturn(loc, result);
}

void OMPExecutableDirective::setClauses(ArrayRef<OMPClause *> Clauses) {
  assert(Clauses.size() == getNumClauses() &&
         "Number of clauses is not the same as the preallocated buffer");
  std::copy(Clauses.begin(), Clauses.end(), getClauses().begin());
}

/// This function goes through the arguments of F and sees if we have anything
/// to optimize in which case it returns true. If we have nothing to optimize,
/// it returns false.
bool FunctionAnalyzer::analyze() {
  // For now ignore functions with indirect results.
  if (F->getLoweredFunctionType()->hasIndirectResult())
    return false;

  ArrayRef<SILArgument *> Args = F->begin()->getBBArgs();

  // A map from consumed SILArguments to the release associated with an
  // argument.
  ConsumedArgToEpilogueReleaseMatcher ArgToReturnReleaseMap(RCIA, F);
  ConsumedArgToEpilogueReleaseMatcher ArgToThrowReleaseMap(
      RCIA, F, ConsumedArgToEpilogueReleaseMatcher::ExitKind::Throw);

  for (unsigned i = 0, e = Args.size(); i != e; ++i) {
    ArgumentDescriptor A(Allocator, Args[i]);
    bool HaveOptimizedArg = false;

    bool isABIRequired = isArgumentABIRequired(Args[i]);
    auto OnlyRelease = getNonTrivialNonDebugReleaseUse(Args[i]);

    // If this argument is not ABI required and has not uses except for debug
    // instructions, remove it.
    if (!isABIRequired && OnlyRelease && OnlyRelease.getValue().isNull()) {
      A.IsDead = true;
      HaveOptimizedArg = true;
      ++NumDeadArgsEliminated;
    }

    // See if we can find a ref count equivalent strong_release or release_value
    // at the end of this function if our argument is an @owned parameter.
    if (A.hasConvention(ParameterConvention::Direct_Owned)) {
      if (auto *Release = ArgToReturnReleaseMap.releaseForArgument(A.Arg)) {
        SILInstruction *ReleaseInThrow = nullptr;

        // If the function has a throw block we must also find a matching
        // release in the throw block.
        if (!ArgToThrowReleaseMap.hasBlock() ||
            (ReleaseInThrow = ArgToThrowReleaseMap.releaseForArgument(A.Arg))) {

          // TODO: accept a second release in the throw block to let the
          // argument be dead.
          if (OnlyRelease && OnlyRelease.getValue().getPtrOrNull() == Release) {
            A.IsDead = true;
          }
          A.CalleeRelease = Release;
          A.CalleeReleaseInThrowBlock = ReleaseInThrow;
          HaveOptimizedArg = true;
          ++NumOwnedConvertedToGuaranteed;
        }
      }
    }

    if (A.shouldExplode()) {
      HaveOptimizedArg = true;
      ++NumSROAArguments;
    }

    if (HaveOptimizedArg) {
      ShouldOptimize = true;
      // Store that we have modified the self argument. We need to change the
      // calling convention later.
      if (Args[i]->isSelf())
        HaveModifiedSelfArgument = true;
    }

    // Add the argument to our list.
    ArgDescList.push_back(std::move(A));
  }

  return ShouldOptimize;
}

void NonNullParamChecker::checkPreCall(const CallEvent &Call,
                                       CheckerContext &C) const {
  const Decl *FD = Call.getDecl();
  if (!FD)
    return;

  // Merge all non-null attributes
  unsigned NumArgs = Call.getNumArgs();
  llvm::SmallBitVector AttrNonNull(NumArgs);
  for (const auto *NonNull : FD->specific_attrs<NonNullAttr>()) {
    if (!NonNull->args_size()) {
      AttrNonNull.set(0, NumArgs);
      break;
    }
    for (unsigned Val : NonNull->args()) {
      if (Val >= NumArgs)
        continue;
      AttrNonNull.set(Val);
    }
  }

  ProgramStateRef state = C.getState();

  CallEvent::param_type_iterator TyI = Call.param_type_begin(),
                                 TyE = Call.param_type_end();

  for (unsigned idx = 0; idx < NumArgs; ++idx) {

    // Check if the parameter is a reference. We want to report when reference
    // to a null pointer is passed as a paramter.
    bool haveRefTypeParam = false;
    if (TyI != TyE) {
      haveRefTypeParam = (*TyI)->isReferenceType();
      TyI++;
    }

    bool haveAttrNonNull = AttrNonNull[idx];
    if (!haveAttrNonNull) {
      // Check if the parameter is also marked 'nonnull'.
      ArrayRef<ParmVarDecl*> parms = Call.parameters();
      if (idx < parms.size())
        haveAttrNonNull = parms[idx]->hasAttr<NonNullAttr>();
    }

    if (!haveRefTypeParam && !haveAttrNonNull)
      continue;

    // If the value is unknown or undefined, we can't perform this check.
    const Expr *ArgE = Call.getArgExpr(idx);
    SVal V = Call.getArgSVal(idx);
    Optional<DefinedSVal> DV = V.getAs<DefinedSVal>();
    if (!DV)
      continue;

    // Process the case when the argument is not a location.
    assert(!haveRefTypeParam || DV->getAs<Loc>());

    if (haveAttrNonNull && !DV->getAs<Loc>()) {
      // If the argument is a union type, we want to handle a potential
      // transparent_union GCC extension.
      if (!ArgE)
        continue;

      QualType T = ArgE->getType();
      const RecordType *UT = T->getAsUnionType();
      if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>())
        continue;

      if (Optional<nonloc::CompoundVal> CSV =
              DV->getAs<nonloc::CompoundVal>()) {
        nonloc::CompoundVal::iterator CSV_I = CSV->begin();
        assert(CSV_I != CSV->end());
        V = *CSV_I;
        DV = V.getAs<DefinedSVal>();
        assert(++CSV_I == CSV->end());
        // FIXME: Handle (some_union){ some_other_union_val }, which turns into
        // a LazyCompoundVal inside a CompoundVal.
        if (!V.getAs<Loc>())
          continue;
        // Retrieve the corresponding expression.
        if (const CompoundLiteralExpr *CE = dyn_cast<CompoundLiteralExpr>(ArgE))
          if (const InitListExpr *IE =
                dyn_cast<InitListExpr>(CE->getInitializer()))
             ArgE = dyn_cast<Expr>(*(IE->begin()));

      } else {
        // FIXME: Handle LazyCompoundVals?
        continue;
      }
    }

    ConstraintManager &CM = C.getConstraintManager();
    ProgramStateRef stateNotNull, stateNull;
    std::tie(stateNotNull, stateNull) = CM.assumeDual(state, *DV);

    if (stateNull) {
      if (!stateNotNull) {
        // Generate an error node.  Check for a null node in case
        // we cache out.
        if (ExplodedNode *errorNode = C.generateErrorNode(stateNull)) {
//.........这里部分代码省略.........

/// Produce note diagnostics for a jump into a protected scope.
void JumpScopeChecker::NoteJumpIntoScopes(ArrayRef<unsigned> ToScopes) {
  assert(!ToScopes.empty());
  for (unsigned I = 0, E = ToScopes.size(); I != E; ++I)
    if (Scopes[ToScopes[I]].InDiag)
      S.Diag(Scopes[ToScopes[I]].Loc, Scopes[ToScopes[I]].InDiag);
}

// Find the minimum offset that we may store a value of size Size bits at. If
// IsAfter is set, look for an offset before the object, otherwise look for an
// offset after the object.
uint64_t
wholeprogramdevirt::findLowestOffset(ArrayRef<VirtualCallTarget> Targets,
                                     bool IsAfter, uint64_t Size) {
  // Find a minimum offset taking into account only vtable sizes.
  uint64_t MinByte = 0;
  for (const VirtualCallTarget &Target : Targets) {
    if (IsAfter)
      MinByte = std::max(MinByte, Target.minAfterBytes());
    else
      MinByte = std::max(MinByte, Target.minBeforeBytes());
  }

  // Build a vector of arrays of bytes covering, for each target, a slice of the
  // used region (see AccumBitVector::BytesUsed in
  // llvm/Transforms/IPO/WholeProgramDevirt.h) starting at MinByte. Effectively,
  // this aligns the used regions to start at MinByte.
  //
  // In this example, A, B and C are vtables, # is a byte already allocated for
  // a virtual function pointer, AAAA... (etc.) are the used regions for the
  // vtables and Offset(X) is the value computed for the Offset variable below
  // for X.
  //
  //                    Offset(A)
  //                    |       |
  //                            |MinByte
  // A: ################AAAAAAAA|AAAAAAAA
  // B: ########BBBBBBBBBBBBBBBB|BBBB
  // C: ########################|CCCCCCCCCCCCCCCC
  //            |   Offset(B)   |
  //
  // This code produces the slices of A, B and C that appear after the divider
  // at MinByte.
  std::vector<ArrayRef<uint8_t>> Used;
  for (const VirtualCallTarget &Target : Targets) {
    ArrayRef<uint8_t> VTUsed = IsAfter ? Target.TM->Bits->After.BytesUsed
                                       : Target.TM->Bits->Before.BytesUsed;
    uint64_t Offset = IsAfter ? MinByte - Target.minAfterBytes()
                              : MinByte - Target.minBeforeBytes();

    // Disregard used regions that are smaller than Offset. These are
    // effectively all-free regions that do not need to be checked.
    if (VTUsed.size() > Offset)
      Used.push_back(VTUsed.slice(Offset));
  }

  if (Size == 1) {
    // Find a free bit in each member of Used.
    for (unsigned I = 0;; ++I) {
      uint8_t BitsUsed = 0;
      for (auto &&B : Used)
        if (I < B.size())
          BitsUsed |= B[I];
      if (BitsUsed != 0xff)
        return (MinByte + I) * 8 +
               countTrailingZeros(uint8_t(~BitsUsed), ZB_Undefined);
    }
  } else {
    // Find a free (Size/8) byte region in each member of Used.
    // FIXME: see if alignment helps.
    for (unsigned I = 0;; ++I) {
      for (auto &&B : Used) {
        unsigned Byte = 0;
        while ((I + Byte) < B.size() && Byte < (Size / 8)) {
          if (B[I + Byte])
            goto NextI;
          ++Byte;
        }
      }
      return (MinByte + I) * 8;
    NextI:;
    }
  }
}

std::auto_ptr<PBQPRAProblem> PBQPBuilder::build(MachineFunction *mf,
                                                const LiveIntervals *lis,
                                                const MachineLoopInfo *loopInfo,
                                                const RegSet &vregs) {

  LiveIntervals *LIS = const_cast<LiveIntervals*>(lis);
  MachineRegisterInfo *mri = &mf->getRegInfo();
  const TargetRegisterInfo *tri = mf->getTarget().getRegisterInfo();

  std::auto_ptr<PBQPRAProblem> p(new PBQPRAProblem());
  PBQP::Graph &g = p->getGraph();
  RegSet pregs;

  // Collect the set of preg intervals, record that they're used in the MF.
  for (unsigned Reg = 1, e = tri->getNumRegs(); Reg != e; ++Reg) {
    if (mri->def_empty(Reg))
      continue;
    pregs.insert(Reg);
    mri->setPhysRegUsed(Reg);
  }

  BitVector reservedRegs = tri->getReservedRegs(*mf);

  // Iterate over vregs.
  for (RegSet::const_iterator vregItr = vregs.begin(), vregEnd = vregs.end();
       vregItr != vregEnd; ++vregItr) {
    unsigned vreg = *vregItr;
    const TargetRegisterClass *trc = mri->getRegClass(vreg);
    LiveInterval *vregLI = &LIS->getInterval(vreg);

    // Record any overlaps with regmask operands.
    BitVector regMaskOverlaps;
    LIS->checkRegMaskInterference(*vregLI, regMaskOverlaps);

    // Compute an initial allowed set for the current vreg.
    typedef std::vector<unsigned> VRAllowed;
    VRAllowed vrAllowed;
    ArrayRef<uint16_t> rawOrder = trc->getRawAllocationOrder(*mf);
    for (unsigned i = 0; i != rawOrder.size(); ++i) {
      unsigned preg = rawOrder[i];
      if (reservedRegs.test(preg))
        continue;

      // vregLI crosses a regmask operand that clobbers preg.
      if (!regMaskOverlaps.empty() && !regMaskOverlaps.test(preg))
        continue;

      // vregLI overlaps fixed regunit interference.
      bool Interference = false;
      for (MCRegUnitIterator Units(preg, tri); Units.isValid(); ++Units) {
        if (vregLI->overlaps(LIS->getRegUnit(*Units))) {
          Interference = true;
          break;
        }
      }
      if (Interference)
        continue;

      // preg is usable for this virtual register.
      vrAllowed.push_back(preg);
    }

    // Construct the node.
    PBQP::Graph::NodeItr node =
      g.addNode(PBQP::Vector(vrAllowed.size() + 1, 0));

    // Record the mapping and allowed set in the problem.
    p->recordVReg(vreg, node, vrAllowed.begin(), vrAllowed.end());

    PBQP::PBQPNum spillCost = (vregLI->weight != 0.0) ?
        vregLI->weight : std::numeric_limits<PBQP::PBQPNum>::min();

    addSpillCosts(g.getNodeCosts(node), spillCost);
  }

  for (RegSet::const_iterator vr1Itr = vregs.begin(), vrEnd = vregs.end();
         vr1Itr != vrEnd; ++vr1Itr) {
    unsigned vr1 = *vr1Itr;
    const LiveInterval &l1 = lis->getInterval(vr1);
    const PBQPRAProblem::AllowedSet &vr1Allowed = p->getAllowedSet(vr1);

    for (RegSet::const_iterator vr2Itr = llvm::next(vr1Itr);
         vr2Itr != vrEnd; ++vr2Itr) {
      unsigned vr2 = *vr2Itr;
      const LiveInterval &l2 = lis->getInterval(vr2);
      const PBQPRAProblem::AllowedSet &vr2Allowed = p->getAllowedSet(vr2);

      assert(!l2.empty() && "Empty interval in vreg set?");
      if (l1.overlaps(l2)) {
        PBQP::Graph::EdgeItr edge =
          g.addEdge(p->getNodeForVReg(vr1), p->getNodeForVReg(vr2),
                    PBQP::Matrix(vr1Allowed.size()+1, vr2Allowed.size()+1, 0));

        addInterferenceCosts(g.getEdgeCosts(edge), vr1Allowed, vr2Allowed, tri);
      }
    }
  }

  return p;
}

MCDisassembler::DecodeStatus WebAssemblyDisassembler::getInstruction(
    MCInst &MI, uint64_t &Size, ArrayRef<uint8_t> Bytes, uint64_t /*Address*/,
    raw_ostream &OS, raw_ostream &CS) const {
  Size = 0;
  uint64_t Pos = 0;

  // Read the opcode.
  if (Pos + sizeof(uint64_t) > Bytes.size())
    return MCDisassembler::Fail;
  uint64_t Opcode = support::endian::read64le(Bytes.data() + Pos);
  Pos += sizeof(uint64_t);

  if (Opcode >= WebAssembly::INSTRUCTION_LIST_END)
    return MCDisassembler::Fail;

  MI.setOpcode(Opcode);
  const MCInstrDesc &Desc = MCII->get(Opcode);
  unsigned NumFixedOperands = Desc.NumOperands;

  // If it's variadic, read the number of extra operands.
  unsigned NumExtraOperands = 0;
  if (Desc.isVariadic()) {
    if (Pos + sizeof(uint64_t) > Bytes.size())
      return MCDisassembler::Fail;
    NumExtraOperands = support::endian::read64le(Bytes.data() + Pos);
    Pos += sizeof(uint64_t);
  }

  // Read the fixed operands. These are described by the MCInstrDesc.
  for (unsigned i = 0; i < NumFixedOperands; ++i) {
    const MCOperandInfo &Info = Desc.OpInfo[i];
    switch (Info.OperandType) {
    case MCOI::OPERAND_IMMEDIATE:
    case WebAssembly::OPERAND_P2ALIGN:
    case WebAssembly::OPERAND_BASIC_BLOCK: {
      if (Pos + sizeof(uint64_t) > Bytes.size())
        return MCDisassembler::Fail;
      uint64_t Imm = support::endian::read64le(Bytes.data() + Pos);
      Pos += sizeof(uint64_t);
      MI.addOperand(MCOperand::createImm(Imm));
      break;
    }
    case MCOI::OPERAND_REGISTER: {
      if (Pos + sizeof(uint64_t) > Bytes.size())
        return MCDisassembler::Fail;
      uint64_t Reg = support::endian::read64le(Bytes.data() + Pos);
      Pos += sizeof(uint64_t);
      MI.addOperand(MCOperand::createReg(Reg));
      break;
    }
    case WebAssembly::OPERAND_FPIMM: {
      // TODO: MC converts all floating point immediate operands to double.
      // This is fine for numeric values, but may cause NaNs to change bits.
      if (Pos + sizeof(uint64_t) > Bytes.size())
        return MCDisassembler::Fail;
      uint64_t Bits = support::endian::read64le(Bytes.data() + Pos);
      Pos += sizeof(uint64_t);
      double Imm;
      memcpy(&Imm, &Bits, sizeof(Imm));
      MI.addOperand(MCOperand::createFPImm(Imm));
      break;
    }
    default:
      llvm_unreachable("unimplemented operand kind");
    }
  }

  // Read the extra operands.
  assert(NumExtraOperands == 0 || Desc.isVariadic());
  for (unsigned i = 0; i < NumExtraOperands; ++i) {
    if (Pos + sizeof(uint64_t) > Bytes.size())
      return MCDisassembler::Fail;
    if (Desc.TSFlags & WebAssemblyII::VariableOpIsImmediate) {
      // Decode extra immediate operands.
      uint64_t Imm = support::endian::read64le(Bytes.data() + Pos);
      MI.addOperand(MCOperand::createImm(Imm));
    } else {
      // Decode extra register operands.
      uint64_t Reg = support::endian::read64le(Bytes.data() + Pos);
      MI.addOperand(MCOperand::createReg(Reg));
    }
    Pos += sizeof(uint64_t);
  }

  Size = Pos;
  return MCDisassembler::Success;
}

void MachineFunction::setCallSiteLandingPad(MCSymbol *Sym,
                                            ArrayRef<unsigned> Sites) {
  LPadToCallSiteMap[Sym].append(Sites.begin(), Sites.end());
}