C++ FunctionType::isVarArg方法代码示例

void Mangler::getNameWithPrefix(raw_ostream &OS, const GlobalValue *GV,
                                bool CannotUsePrivateLabel) const {
  ManglerPrefixTy PrefixTy = Default;
  if (GV->hasPrivateLinkage()) {
    if (CannotUsePrivateLabel)
      PrefixTy = LinkerPrivate;
    else
      PrefixTy = Private;
  }

  const DataLayout &DL = GV->getParent()->getDataLayout();
  if (!GV->hasName()) {
    // Get the ID for the global, assigning a new one if we haven't got one
    // already.
    unsigned &ID = AnonGlobalIDs[GV];
    if (ID == 0)
      ID = AnonGlobalIDs.size();

    // Must mangle the global into a unique ID.
    getNameWithPrefixImpl(OS, "__unnamed_" + Twine(ID), DL, PrefixTy);
    return;
  }

  StringRef Name = GV->getName();
  char Prefix = DL.getGlobalPrefix();

  // Mangle functions with Microsoft calling conventions specially.  Only do
  // this mangling for x86_64 vectorcall and 32-bit x86.
  const Function *MSFunc = dyn_cast<Function>(GV);
  if (Name.startswith("\01"))
    MSFunc = nullptr; // Don't mangle when \01 is present.
  CallingConv::ID CC =
      MSFunc ? MSFunc->getCallingConv() : (unsigned)CallingConv::C;
  if (!DL.hasMicrosoftFastStdCallMangling() &&
      CC != CallingConv::X86_VectorCall)
    MSFunc = nullptr;
  if (MSFunc) {
    if (CC == CallingConv::X86_FastCall)
      Prefix = '@'; // fastcall functions have an @ prefix instead of _.
    else if (CC == CallingConv::X86_VectorCall)
      Prefix = '\0'; // vectorcall functions have no prefix.
  }

  getNameWithPrefixImpl(OS, Name, PrefixTy, DL, Prefix);

  if (!MSFunc)
    return;

  // If we are supposed to add a microsoft-style suffix for stdcall, fastcall,
  // or vectorcall, add it.  These functions have a suffix of @N where N is the
  // cumulative byte size of all of the parameters to the function in decimal.
  if (CC == CallingConv::X86_VectorCall)
    OS << '@'; // vectorcall functions use a double @ suffix.
  FunctionType *FT = MSFunc->getFunctionType();
  if (hasByteCountSuffix(CC) &&
      // "Pure" variadic functions do not receive @0 suffix.
      (!FT->isVarArg() || FT->getNumParams() == 0 ||
       (FT->getNumParams() == 1 && MSFunc->hasStructRetAttr())))
    addByteCountSuffix(OS, MSFunc, DL);
}

Function *WebAssemblyLowerEmscriptenEHSjLj::getInvokeWrapper(CallOrInvoke *CI) {
  Module *M = CI->getModule();
  SmallVector<Type *, 16> ArgTys;
  Value *Callee = CI->getCalledValue();
  FunctionType *CalleeFTy;
  if (auto *F = dyn_cast<Function>(Callee))
    CalleeFTy = F->getFunctionType();
  else {
    auto *CalleeTy = cast<PointerType>(Callee->getType())->getElementType();
    CalleeFTy = dyn_cast<FunctionType>(CalleeTy);
  }

  std::string Sig = getSignature(CalleeFTy);
  if (InvokeWrappers.find(Sig) != InvokeWrappers.end())
    return InvokeWrappers[Sig];

  // Put the pointer to the callee as first argument
  ArgTys.push_back(PointerType::getUnqual(CalleeFTy));
  // Add argument types
  ArgTys.append(CalleeFTy->param_begin(), CalleeFTy->param_end());

  FunctionType *FTy = FunctionType::get(CalleeFTy->getReturnType(), ArgTys,
                                        CalleeFTy->isVarArg());
  Function *F = Function::Create(FTy, GlobalValue::ExternalLinkage,
                                 InvokePrefix + Sig, M);
  InvokeWrappers[Sig] = F;
  return F;
}

// Get the value we should change this callsite to call instead.
Value *CSDataRando::getCloneCalledValue(CallSite CS, FuncInfo &CalleeInfo) {
  if (CalleeInfo.ArgNodes.size() == 0) {
    return nullptr;
  }

  // Find the function type we want based on how many args need to be added. We
  // do this in case the original function has been cast to a different type.
  FunctionType *FT = CS.getFunctionType();
  SmallVector<Type*, 8> Params;
  Params.insert(Params.end(), FT->param_begin(), FT->param_end());
  Params.insert(Params.end(), CalleeInfo.ArgNodes.size(), MaskTy);
  FunctionType *TargetType = FunctionType::get(FT->getReturnType(), Params, FT->isVarArg());

  IRBuilder<> Builder(CS.getInstruction());

  // Direct call, find the clone and cast it to what we want.
  if (Function *F = dyn_cast<Function>(CS.getCalledValue()->stripPointerCasts())) {
    Value *Clone = OldToNewFuncMap[F];
    if (Clone) {
      Clone = Builder.CreateBitCast(Clone, PointerType::getUnqual(TargetType));
    }
    return Clone;
  }

  // Indirect calls, cast the called value to the type we want.
  Value *CalledValue = CS.getCalledValue();
  return Builder.CreateBitCast(CalledValue, PointerType::getUnqual(TargetType));
}

void Mangler::getNameWithPrefix(raw_ostream &OS, const GlobalValue *GV,
                                bool CannotUsePrivateLabel) const {
  ManglerPrefixTy PrefixTy = Mangler::Default;
  if (GV->hasPrivateLinkage()) {
    if (CannotUsePrivateLabel)
      PrefixTy = Mangler::LinkerPrivate;
    else
      PrefixTy = Mangler::Private;
  }

  if (!GV->hasName()) {
    // Get the ID for the global, assigning a new one if we haven't got one
    // already.
    unsigned &ID = AnonGlobalIDs[GV];
    if (ID == 0)
      ID = NextAnonGlobalID++;

    // Must mangle the global into a unique ID.
    getNameWithPrefix(OS, "__unnamed_" + Twine(ID), PrefixTy);
    return;
  }

  StringRef Name = GV->getName();

  // No need to do anything special if the global has the special "do not
  // mangle" flag in the name.
  if (Name[0] == '\1') {
    OS << Name.substr(1);
    return;
  }

  bool UseAt = false;
  const Function *MSFunc = nullptr;
  CallingConv::ID CC;
  if (DL->hasMicrosoftFastStdCallMangling()) {
    if ((MSFunc = dyn_cast<Function>(GV))) {
      CC = MSFunc->getCallingConv();
      // fastcall functions need to start with @ instead of _.
      if (CC == CallingConv::X86_FastCall)
        UseAt = true;
    }
  }

  getNameWithPrefixx(OS, Name, PrefixTy, *DL, UseAt);

  if (!MSFunc)
    return;

  // If we are supposed to add a microsoft-style suffix for stdcall/fastcall,
  // add it.
  // fastcall and stdcall functions usually need @42 at the end to specify
  // the argument info.
  FunctionType *FT = MSFunc->getFunctionType();
  if ((CC == CallingConv::X86_FastCall || CC == CallingConv::X86_StdCall) &&
      // "Pure" variadic functions do not receive @0 suffix.
      (!FT->isVarArg() || FT->getNumParams() == 0 ||
       (FT->getNumParams() == 1 && MSFunc->hasStructRetAttr())))
    AddFastCallStdCallSuffix(OS, MSFunc, *DL);
}

void Mapper::remapInstruction(Instruction *I) {
  // Remap operands.
  for (Use &Op : I->operands()) {
    Value *V = mapValue(Op);
    // If we aren't ignoring missing entries, assert that something happened.
    if (V)
      Op = V;
    else
      assert((Flags & RF_IgnoreMissingLocals) &&
             "Referenced value not in value map!");
  }

  // Remap phi nodes' incoming blocks.
  if (PHINode *PN = dyn_cast<PHINode>(I)) {
    for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
      Value *V = mapValue(PN->getIncomingBlock(i));
      // If we aren't ignoring missing entries, assert that something happened.
      if (V)
        PN->setIncomingBlock(i, cast<BasicBlock>(V));
      else
        assert((Flags & RF_IgnoreMissingLocals) &&
               "Referenced block not in value map!");
    }
  }

  // Remap attached metadata.
  SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
  I->getAllMetadata(MDs);
  for (const auto &MI : MDs) {
    MDNode *Old = MI.second;
    MDNode *New = cast_or_null<MDNode>(mapMetadata(Old));
    if (New != Old)
      I->setMetadata(MI.first, New);
  }

  if (!TypeMapper)
    return;

  // If the instruction's type is being remapped, do so now.
  if (auto CS = CallSite(I)) {
    SmallVector<Type *, 3> Tys;
    FunctionType *FTy = CS.getFunctionType();
    Tys.reserve(FTy->getNumParams());
    for (Type *Ty : FTy->params())
      Tys.push_back(TypeMapper->remapType(Ty));
    CS.mutateFunctionType(FunctionType::get(
        TypeMapper->remapType(I->getType()), Tys, FTy->isVarArg()));
    return;
  }
  if (auto *AI = dyn_cast<AllocaInst>(I))
    AI->setAllocatedType(TypeMapper->remapType(AI->getAllocatedType()));
  if (auto *GEP = dyn_cast<GetElementPtrInst>(I)) {
    GEP->setSourceElementType(
        TypeMapper->remapType(GEP->getSourceElementType()));
    GEP->setResultElementType(
        TypeMapper->remapType(GEP->getResultElementType()));
  }
  I->mutateType(TypeMapper->remapType(I->getType()));
}

/// RemapInstruction - Convert the instruction operands from referencing the
/// current values into those specified by VMap.
///
void llvm::RemapInstruction(Instruction *I, ValueToValueMapTy &VMap,
                            RemapFlags Flags, ValueMapTypeRemapper *TypeMapper,
                            ValueMaterializer *Materializer){
  // Remap operands.
  for (User::op_iterator op = I->op_begin(), E = I->op_end(); op != E; ++op) {
    Value *V = MapValue(*op, VMap, Flags, TypeMapper, Materializer);
    // If we aren't ignoring missing entries, assert that something happened.
    if (V)
      *op = V;
    else
      assert((Flags & RF_IgnoreMissingEntries) &&
             "Referenced value not in value map!");
  }

  // Remap phi nodes' incoming blocks.
  if (PHINode *PN = dyn_cast<PHINode>(I)) {
    for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
      Value *V = MapValue(PN->getIncomingBlock(i), VMap, Flags);
      // If we aren't ignoring missing entries, assert that something happened.
      if (V)
        PN->setIncomingBlock(i, cast<BasicBlock>(V));
      else
        assert((Flags & RF_IgnoreMissingEntries) &&
               "Referenced block not in value map!");
    }
  }

  // Remap attached metadata.
  SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
  I->getAllMetadata(MDs);
  for (SmallVectorImpl<std::pair<unsigned, MDNode *>>::iterator
           MI = MDs.begin(),
           ME = MDs.end();
       MI != ME; ++MI) {
    MDNode *Old = MI->second;
    MDNode *New = MapMetadata(Old, VMap, Flags, TypeMapper, Materializer);
    if (New != Old)
      I->setMetadata(MI->first, New);
  }
  
  if (!TypeMapper)
    return;

  // If the instruction's type is being remapped, do so now.
  if (auto CS = CallSite(I)) {
    SmallVector<Type *, 3> Tys;
    FunctionType *FTy = CS.getFunctionType();
    Tys.reserve(FTy->getNumParams());
    for (Type *Ty : FTy->params())
      Tys.push_back(TypeMapper->remapType(Ty));
    CS.mutateFunctionType(FunctionType::get(
        TypeMapper->remapType(I->getType()), Tys, FTy->isVarArg()));
  } else
    I->mutateType(TypeMapper->remapType(I->getType()));
}

/// getNameWithPrefix - Fill OutName with the name of the appropriate prefix
/// and the specified global variable's name.  If the global variable doesn't
/// have a name, this fills in a unique name for the global.
void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName,
                                const GlobalValue *GV) {
  ManglerPrefixTy PrefixTy = Mangler::Default;
  if (GV->hasPrivateLinkage())
    PrefixTy = Mangler::Private;
  else if (GV->hasLinkerPrivateLinkage() || GV->hasLinkerPrivateWeakLinkage())
    PrefixTy = Mangler::LinkerPrivate;
  
  // If this global has a name, handle it simply.
  if (GV->hasName()) {
    StringRef Name = GV->getName();
    getNameWithPrefix(OutName, Name, PrefixTy);
    // No need to do anything else if the global has the special "do not mangle"
    // flag in the name.
    if (Name[0] == 1)
      return;
  } else {
    // Get the ID for the global, assigning a new one if we haven't got one
    // already.
    unsigned &ID = AnonGlobalIDs[GV];
    if (ID == 0) ID = NextAnonGlobalID++;
  
    // Must mangle the global into a unique ID.
    getNameWithPrefix(OutName, "__unnamed_" + Twine(ID), PrefixTy);
  }

  // If we are supposed to add a microsoft-style suffix for stdcall/fastcall,
  // add it.
  if (DL->hasMicrosoftFastStdCallMangling()) {
    if (const Function *F = dyn_cast<Function>(GV)) {
      CallingConv::ID CC = F->getCallingConv();
    
      // fastcall functions need to start with @.
      // FIXME: This logic seems unlikely to be right.
      if (CC == CallingConv::X86_FastCall) {
        if (OutName[0] == '_')
          OutName[0] = '@';
        else
          OutName.insert(OutName.begin(), '@');
      }
    
      // fastcall and stdcall functions usually need @42 at the end to specify
      // the argument info.
      FunctionType *FT = F->getFunctionType();
      if ((CC == CallingConv::X86_FastCall || CC == CallingConv::X86_StdCall) &&
          // "Pure" variadic functions do not receive @0 suffix.
          (!FT->isVarArg() || FT->getNumParams() == 0 ||
           (FT->getNumParams() == 1 && F->hasStructRetAttr())))
        AddFastCallStdCallSuffix(OutName, F, *DL);
    }
  }
}

/// Creates a hash-code for the function which is the same for any two
/// functions that will compare equal, without looking at the instructions
/// inside the function.
static unsigned profileFunction(const Function *F) {
  FunctionType *FTy = F->getFunctionType();

  FoldingSetNodeID ID;
  ID.AddInteger(F->size());
  ID.AddInteger(F->getCallingConv());
  ID.AddBoolean(F->hasGC());
  ID.AddBoolean(FTy->isVarArg());
  ID.AddInteger(getTypeIDForHash(FTy->getReturnType()));
  for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
    ID.AddInteger(getTypeIDForHash(FTy->getParamType(i)));
  return ID.ComputeHash();
}

void llvm::computeUsesVAFloatArgument(const CallInst &I,
                                      MachineModuleInfo &MMI) {
  FunctionType *FT =
      cast<FunctionType>(I.getCalledValue()->getType()->getContainedType(0));
  if (FT->isVarArg() && !MMI.usesVAFloatArgument()) {
    for (unsigned i = 0, e = I.getNumArgOperands(); i != e; ++i) {
      Type *T = I.getArgOperand(i)->getType();
      for (auto i : post_order(T)) {
        if (i->isFloatingPointTy()) {
          MMI.setUsesVAFloatArgument(true);
          return;
        }
      }
    }
  }
}

// Maybe make a clone, if a clone is made, return a pointer to it, if a clone
// was not made return nullptr.
Function *CSDataRando::makeFunctionClone(Function *F) {
  // Now we know how many arguments need to be passed, so we make the clones
  FuncInfo &FI = FunctionInfo[F];
  if (FI.ArgNodes.size() == 0) {
    // No additional args to pass, no need to clone.
    return nullptr;
  }
  // Determine the type of the new function, we insert the new parameters for
  // the masks after the normal arguments, but before any va_args
  Type *MaskTy = TypeBuilder<mask_t, false>::get(F->getContext());
  FunctionType *OldFuncTy = F->getFunctionType();
  std::vector<Type*> ArgTys;
  ArgTys.insert(ArgTys.end(), OldFuncTy->param_begin(), OldFuncTy->param_end());
  ArgTys.insert(ArgTys.end(), FI.ArgNodes.size(), MaskTy);
  FunctionType *CloneFuncTy = FunctionType::get(OldFuncTy->getReturnType(), ArgTys, OldFuncTy->isVarArg());

  Function *Clone = Function::Create(CloneFuncTy, Function::InternalLinkage, F->getName() + "_CONTEXT_SENSITIVE");
  F->getParent()->getFunctionList().insert(F->getIterator(), Clone);

  Function::arg_iterator CI = Clone->arg_begin(), CE = Clone->arg_end();

  // Map the old arguments to the clone arguments and set the name of the
  // clone arguments the same as the original.
  for (Function::arg_iterator i = F->arg_begin(), e = F->arg_end(); i != e && CI != CE; i++, CI++) {
    FI.OldToNewMap[&*i] = &*CI;
    CI->setName(i->getName());
  }

  // Set the name of the arg masks and associate them with the nodes they are
  // the masks for.
  for (unsigned i = 0, e = FI.ArgNodes.size(); i != e; ++i, ++CI) {
    CI->setName("arg_mask");
    FI.ArgMaskMap[FI.ArgNodes[i]] = &*CI;
  }

  SmallVector<ReturnInst*, 8> Returns;
  CloneFunctionInto(Clone, F, FI.OldToNewMap, false, Returns);
  Clone->setCallingConv(F->getCallingConv());

  // Invert OldToNewMap
  for (auto I : FI.OldToNewMap) {
    FI.NewToOldMap[I.second] = I.first;
  }

  NumClones++;
  return Clone;
}

/// ComputeUsesVAFloatArgument - Determine if any floating-point values are
/// being passed to this variadic function, and set the MachineModuleInfo's
/// usesVAFloatArgument flag if so. This flag is used to emit an undefined
/// reference to _fltused on Windows, which will link in MSVCRT's
/// floating-point support.
void llvm::ComputeUsesVAFloatArgument(const CallInst &I,
                                      MachineModuleInfo *MMI)
{
    FunctionType *FT = cast<FunctionType>(
                           I.getCalledValue()->getType()->getContainedType(0));
    if (FT->isVarArg() && !MMI->usesVAFloatArgument()) {
        for (unsigned i = 0, e = I.getNumArgOperands(); i != e; ++i) {
            Type* T = I.getArgOperand(i)->getType();
            for (po_iterator<Type*> i = po_begin(T), e = po_end(T);
                    i != e; ++i) {
                if (i->isFloatingPointTy()) {
                    MMI->setUsesVAFloatArgument(true);
                    return;
                }
            }
        }
    }
}

static void check(Value *Func, ArrayRef<Value *> Args) {
  FunctionType *FTy =
      cast<FunctionType>(cast<PointerType>(Func->getType())->getElementType());

  assert((Args.size() == FTy->getNumParams() ||
          (FTy->isVarArg() && Args.size() > FTy->getNumParams())) &&
         "XXCalling a function with bad signature!");

  for (unsigned i = 0; i != Args.size(); ++i) {
    if (!(FTy->getParamType(i) == Args[i]->getType())) {
      errs() << "types:\n  ";
      FTy->getParamType(i)->dump();
      errs() << "\n  ";
      Args[i]->getType()->dump();
      errs() << "\n";
    }
    assert((i >= FTy->getNumParams() ||
            FTy->getParamType(i) == Args[i]->getType()) &&
           "YYCalling a function with a bad signature!");
  }
}

void Preparer::expandCallSite(CallSite CS) {
  // Skip the callsites that are not calling a va function.
  Value *Callee = CS.getCalledValue();
  FunctionType *CalleeType = cast<FunctionType>(
      cast<PointerType>(Callee->getType())->getElementType());
  if (!CalleeType->isVarArg()) {
    return;
  }

  vector<Value *> Args;
  for (CallSite::arg_iterator ArgI = CS.arg_begin();
      ArgI != CS.arg_end(); ArgI++) {
    Args.push_back(*ArgI);
  }
  Args.push_back(ConstantInt::get(
        IntegerType::get(CS.getInstruction()->getContext(), 8), 0));
  string InstName = "";
  if (CS.getInstruction()->getName() != "")
    InstName = CS.getInstruction()->getName().str() + ".padded";
  if (CallInst *CI = dyn_cast<CallInst>(CS.getInstruction())) {
    CallInst *NewCI = CallInst::Create(Callee, Args, InstName, CI);
    NewCI->setAttributes(CI->getAttributes());
    CI->replaceAllUsesWith(NewCI);
    CI->eraseFromParent();
  } else if (InvokeInst *II = dyn_cast<InvokeInst>(CS.getInstruction())) {
    InvokeInst *NewII = InvokeInst::Create(Callee,
                                           II->getNormalDest(),
                                           II->getUnwindDest(),
                                           Args,
                                           InstName,
                                           II);
    NewII->setAttributes(II->getAttributes());
    II->replaceAllUsesWith(NewII);
    II->eraseFromParent();
  }
}

/// cmpType - compares two types,
/// defines total ordering among the types set.
/// See method declaration comments for more details.
int FunctionComparator::cmpType(Type *TyL, Type *TyR) const {

  PointerType *PTyL = dyn_cast<PointerType>(TyL);
  PointerType *PTyR = dyn_cast<PointerType>(TyR);

  if (DL) {
    if (PTyL && PTyL->getAddressSpace() == 0) TyL = DL->getIntPtrType(TyL);
    if (PTyR && PTyR->getAddressSpace() == 0) TyR = DL->getIntPtrType(TyR);
  }

  if (TyL == TyR)
    return 0;

  if (int Res = cmpNumbers(TyL->getTypeID(), TyR->getTypeID()))
    return Res;

  switch (TyL->getTypeID()) {
  default:
    llvm_unreachable("Unknown type!");
    // Fall through in Release mode.
  case Type::IntegerTyID:
  case Type::VectorTyID:
    // TyL == TyR would have returned true earlier.
    return cmpNumbers((uint64_t)TyL, (uint64_t)TyR);

  case Type::VoidTyID:
  case Type::FloatTyID:
  case Type::DoubleTyID:
  case Type::X86_FP80TyID:
  case Type::FP128TyID:
  case Type::PPC_FP128TyID:
  case Type::LabelTyID:
  case Type::MetadataTyID:
    return 0;

  case Type::PointerTyID: {
    assert(PTyL && PTyR && "Both types must be pointers here.");
    return cmpNumbers(PTyL->getAddressSpace(), PTyR->getAddressSpace());
  }

  case Type::StructTyID: {
    StructType *STyL = cast<StructType>(TyL);
    StructType *STyR = cast<StructType>(TyR);
    if (STyL->getNumElements() != STyR->getNumElements())
      return cmpNumbers(STyL->getNumElements(), STyR->getNumElements());

    if (STyL->isPacked() != STyR->isPacked())
      return cmpNumbers(STyL->isPacked(), STyR->isPacked());

    for (unsigned i = 0, e = STyL->getNumElements(); i != e; ++i) {
      if (int Res = cmpType(STyL->getElementType(i),
                            STyR->getElementType(i)))
        return Res;
    }
    return 0;
  }

  case Type::FunctionTyID: {
    FunctionType *FTyL = cast<FunctionType>(TyL);
    FunctionType *FTyR = cast<FunctionType>(TyR);
    if (FTyL->getNumParams() != FTyR->getNumParams())
      return cmpNumbers(FTyL->getNumParams(), FTyR->getNumParams());

    if (FTyL->isVarArg() != FTyR->isVarArg())
      return cmpNumbers(FTyL->isVarArg(), FTyR->isVarArg());

    if (int Res = cmpType(FTyL->getReturnType(), FTyR->getReturnType()))
      return Res;

    for (unsigned i = 0, e = FTyL->getNumParams(); i != e; ++i) {
      if (int Res = cmpType(FTyL->getParamType(i), FTyR->getParamType(i)))
        return Res;
    }
    return 0;
  }

  case Type::ArrayTyID: {
    ArrayType *ATyL = cast<ArrayType>(TyL);
    ArrayType *ATyR = cast<ArrayType>(TyR);
    if (ATyL->getNumElements() != ATyR->getNumElements())
      return cmpNumbers(ATyL->getNumElements(), ATyR->getNumElements());
    return cmpType(ATyL->getElementType(), ATyR->getElementType());
  }
  }
}

void Lint::visitCallSite(CallSite CS) {
  Instruction &I = *CS.getInstruction();
  Value *Callee = CS.getCalledValue();

  visitMemoryReference(I, Callee, MemoryLocation::UnknownSize, 0, nullptr,
                       MemRef::Callee);

  if (Function *F = dyn_cast<Function>(findValue(Callee,
                                                 /*OffsetOk=*/false))) {
    Assert(CS.getCallingConv() == F->getCallingConv(),
           "Undefined behavior: Caller and callee calling convention differ",
           &I);

    FunctionType *FT = F->getFunctionType();
    unsigned NumActualArgs = CS.arg_size();

    Assert(FT->isVarArg() ? FT->getNumParams() <= NumActualArgs
                          : FT->getNumParams() == NumActualArgs,
           "Undefined behavior: Call argument count mismatches callee "
           "argument count",
           &I);

    Assert(FT->getReturnType() == I.getType(),
           "Undefined behavior: Call return type mismatches "
           "callee return type",
           &I);

    // Check argument types (in case the callee was casted) and attributes.
    // TODO: Verify that caller and callee attributes are compatible.
    Function::arg_iterator PI = F->arg_begin(), PE = F->arg_end();
    CallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end();
    for (; AI != AE; ++AI) {
      Value *Actual = *AI;
      if (PI != PE) {
        Argument *Formal = &*PI++;
        Assert(Formal->getType() == Actual->getType(),
               "Undefined behavior: Call argument type mismatches "
               "callee parameter type",
               &I);

        // Check that noalias arguments don't alias other arguments. This is
        // not fully precise because we don't know the sizes of the dereferenced
        // memory regions.
        if (Formal->hasNoAliasAttr() && Actual->getType()->isPointerTy())
          for (CallSite::arg_iterator BI = CS.arg_begin(); BI != AE; ++BI)
            if (AI != BI && (*BI)->getType()->isPointerTy()) {
              AliasResult Result = AA->alias(*AI, *BI);
              Assert(Result != MustAlias && Result != PartialAlias,
                     "Unusual: noalias argument aliases another argument", &I);
            }

        // Check that an sret argument points to valid memory.
        if (Formal->hasStructRetAttr() && Actual->getType()->isPointerTy()) {
          Type *Ty =
            cast<PointerType>(Formal->getType())->getElementType();
          visitMemoryReference(I, Actual, DL->getTypeStoreSize(Ty),
                               DL->getABITypeAlignment(Ty), Ty,
                               MemRef::Read | MemRef::Write);
        }
      }
    }
  }

  if (CS.isCall() && cast<CallInst>(CS.getInstruction())->isTailCall())
    for (CallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end();
         AI != AE; ++AI) {
      Value *Obj = findValue(*AI, /*OffsetOk=*/true);
      Assert(!isa<AllocaInst>(Obj),
             "Undefined behavior: Call with \"tail\" keyword references "
             "alloca",
             &I);
    }


  if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(&I))
    switch (II->getIntrinsicID()) {
    default: break;

    // TODO: Check more intrinsics

    case Intrinsic::memcpy: {
      MemCpyInst *MCI = cast<MemCpyInst>(&I);
      // TODO: If the size is known, use it.
      visitMemoryReference(I, MCI->getDest(), MemoryLocation::UnknownSize,
                           MCI->getAlignment(), nullptr, MemRef::Write);
      visitMemoryReference(I, MCI->getSource(), MemoryLocation::UnknownSize,
                           MCI->getAlignment(), nullptr, MemRef::Read);

      // Check that the memcpy arguments don't overlap. The AliasAnalysis API
      // isn't expressive enough for what we really want to do. Known partial
      // overlap is not distinguished from the case where nothing is known.
      uint64_t Size = 0;
      if (const ConstantInt *Len =
              dyn_cast<ConstantInt>(findValue(MCI->getLength(),
                                              /*OffsetOk=*/false)))
        if (Len->getValue().isIntN(32))
          Size = Len->getValue().getZExtValue();
      Assert(AA->alias(MCI->getSource(), Size, MCI->getDest(), Size) !=
                 MustAlias,
             "Undefined behavior: memcpy source and destination overlap", &I);
//.........这里部分代码省略.........