C++ FunctionType::getContext方法代码示例

/// \brief Returns the allocation data for the given value if it is a call to a
/// known allocation function, and NULL otherwise.
static const AllocFnsTy *getAllocationData(const Value *V, AllocType AllocTy,
                                           const TargetLibraryInfo *TLI,
                                           bool LookThroughBitCast = false) {
  // Skip all intrinsics but duetto.allocate
  if (const IntrinsicInst* II = dyn_cast<IntrinsicInst>(V))
  {
    if (II->getIntrinsicID() == Intrinsic::duetto_allocate)
      return &AllocationFnData[0];
    return 0;
  }

  Function *Callee = getCalledFunction(V, LookThroughBitCast);
  if (!Callee)
    return 0;

  // Make sure that the function is available.
  StringRef FnName = Callee->getName();
  LibFunc::Func TLIFn;
  if (!TLI || !TLI->getLibFunc(FnName, TLIFn) || !TLI->has(TLIFn))
    return 0;

  unsigned i = 0;
  bool found = false;
  for ( ; i < array_lengthof(AllocationFnData); ++i) {
    if (AllocationFnData[i].Func == TLIFn) {
      found = true;
      break;
    }
  }
  if (!found)
    return 0;

  const AllocFnsTy *FnData = &AllocationFnData[i];
  if ((FnData->AllocTy & AllocTy) != FnData->AllocTy)
    return 0;

  // Check function prototype.
  int FstParam = FnData->FstParam;
  int SndParam = FnData->SndParam;
  FunctionType *FTy = Callee->getFunctionType();

  if (FTy->getReturnType() == Type::getInt8PtrTy(FTy->getContext()) &&
      FTy->getNumParams() == FnData->NumParams &&
      (FstParam < 0 ||
       (FTy->getParamType(FstParam)->isIntegerTy(32) ||
        FTy->getParamType(FstParam)->isIntegerTy(64))) &&
      (SndParam < 0 ||
       FTy->getParamType(SndParam)->isIntegerTy(32) ||
       FTy->getParamType(SndParam)->isIntegerTy(64)))
    return FnData;
  return 0;
}

/// \brief Returns the allocation data for the given value if it is a call to a
/// known allocation function, and NULL otherwise.
static const AllocFnsTy *getAllocationData(const Value *V, AllocType AllocTy,
                                           const TargetLibraryInfo *TLI,
                                           bool LookThroughBitCast = false) {
  // Skip intrinsics
  if (isa<IntrinsicInst>(V))
    return nullptr;

  Function *Callee = getCalledFunction(V, LookThroughBitCast);
  if (!Callee)
    return nullptr;

  // Make sure that the function is available.
  StringRef FnName = Callee->getName();
  LibFunc::Func TLIFn;
  if (!TLI || !TLI->getLibFunc(FnName, TLIFn) || !TLI->has(TLIFn))
    return nullptr;

  const AllocFnsTy *FnData =
      std::find_if(std::begin(AllocationFnData), std::end(AllocationFnData),
                   [TLIFn](const AllocFnsTy &Fn) { return Fn.Func == TLIFn; });

  if (FnData == std::end(AllocationFnData))
    return nullptr;

  if ((FnData->AllocTy & AllocTy) != FnData->AllocTy)
    return nullptr;

  // Check function prototype.
  int FstParam = FnData->FstParam;
  int SndParam = FnData->SndParam;
  FunctionType *FTy = Callee->getFunctionType();

  if (FTy->getReturnType() == Type::getInt8PtrTy(FTy->getContext()) &&
      FTy->getNumParams() == FnData->NumParams &&
      (FstParam < 0 ||
       (FTy->getParamType(FstParam)->isIntegerTy(32) ||
        FTy->getParamType(FstParam)->isIntegerTy(64))) &&
      (SndParam < 0 ||
       FTy->getParamType(SndParam)->isIntegerTy(32) ||
       FTy->getParamType(SndParam)->isIntegerTy(64)))
    return FnData;
  return nullptr;
}

static bool isCallocCall(const CallInst *CI) {
  if (!CI)
    return false;
  
  Function *Callee = CI->getCalledFunction();
  if (Callee == 0 || !Callee->isDeclaration())
    return false;
  if (Callee->getName() != "calloc")
    return false;
  
  // Check malloc prototype.
  // FIXME: workaround for PR5130, this will be obsolete when a nobuiltin 
  // attribute exists.
  FunctionType *FTy = Callee->getFunctionType();
  return FTy->getReturnType() == Type::getInt8PtrTy(FTy->getContext()) &&
  FTy->getNumParams() == 2 &&
  ((FTy->getParamType(0)->isIntegerTy(32) &&
    FTy->getParamType(1)->isIntegerTy(32)) ||
   (FTy->getParamType(0)->isIntegerTy(64) &&
    FTy->getParamType(1)->isIntegerTy(64)));
}

// TODO Copy-paste
static bool isMallocCall(const CallInst* CI) {
    if (!CI)
        return false;

    Function* Callee = CI->getCalledFunction();
    if (Callee == 0 || !Callee->isDeclaration())
        return false;
    if (Callee->getName() != "malloc" /*&&
            Callee->getName() != "my_malloc" &&
            Callee->getName() != "_Znwj" && // operator new(unsigned int)
            Callee->getName() != "_Znwm" && // operator new(unsigned long)
            Callee->getName() != "_Znaj" && // operator new[](unsigned int)
            Callee->getName() != "_Znam"*/) // operator new[](unsigned long)
        return false;

    // Check malloc prototype.
    // FIXME: workaround for PR5130, this will be obsolete when a nobuiltin
    // attribute will exist.
    FunctionType* FTy = Callee->getFunctionType();
    return FTy->getReturnType() == Type::getInt8PtrTy(FTy->getContext()) && FTy->getNumParams() == 1
           && (FTy->getParamType(0)->isIntegerTy(32) || FTy->getParamType(0)->isIntegerTy(64));
}

/// \brief Returns the allocation data for the given value if it is a call to a
/// known allocation function, and NULL otherwise.
static const AllocFnsTy *getAllocationData(const Value *V, AllocType AllocTy,
                                           bool LookThroughBitCast = false) {
  Function *Callee = getCalledFunction(V, LookThroughBitCast);
  if (!Callee)
    return 0;

  unsigned i = 0;
  bool found = false;
  for ( ; i < array_lengthof(AllocationFnData); ++i) {
    if (Callee->getName() == AllocationFnData[i].Name) {
      found = true;
      break;
    }
  }
  if (!found)
    return 0;

  const AllocFnsTy *FnData = &AllocationFnData[i];
  if ((FnData->AllocTy & AllocTy) == 0)
    return 0;

  // Check function prototype.
  // FIXME: Check the nobuiltin metadata?? (PR5130)
  int FstParam = FnData->FstParam;
  int SndParam = FnData->SndParam;
  FunctionType *FTy = Callee->getFunctionType();

  if (FTy->getReturnType() == Type::getInt8PtrTy(FTy->getContext()) &&
      FTy->getNumParams() == FnData->NumParams &&
      (FstParam < 0 ||
       (FTy->getParamType(FstParam)->isIntegerTy(32) ||
        FTy->getParamType(FstParam)->isIntegerTy(64))) &&
      (SndParam < 0 ||
       FTy->getParamType(SndParam)->isIntegerTy(32) ||
       FTy->getParamType(SndParam)->isIntegerTy(64)))
    return FnData;
  return 0;
}

/// Returns the allocation data for the given value if it's either a call to a
/// known allocation function, or a call to a function with the allocsize
/// attribute.
static Optional<AllocFnsTy>
getAllocationDataForFunction(const Function *Callee, AllocType AllocTy,
                             const TargetLibraryInfo *TLI) {
  // Make sure that the function is available.
  StringRef FnName = Callee->getName();
  LibFunc TLIFn;
  if (!TLI || !TLI->getLibFunc(FnName, TLIFn) || !TLI->has(TLIFn))
    return None;

  const auto *Iter = find_if(
      AllocationFnData, [TLIFn](const std::pair<LibFunc, AllocFnsTy> &P) {
        return P.first == TLIFn;
      });

  if (Iter == std::end(AllocationFnData))
    return None;

  const AllocFnsTy *FnData = &Iter->second;
  if ((FnData->AllocTy & AllocTy) != FnData->AllocTy)
    return None;

  // Check function prototype.
  int FstParam = FnData->FstParam;
  int SndParam = FnData->SndParam;
  FunctionType *FTy = Callee->getFunctionType();

  if (FTy->getReturnType() == Type::getInt8PtrTy(FTy->getContext()) &&
      FTy->getNumParams() == FnData->NumParams &&
      (FstParam < 0 ||
       (FTy->getParamType(FstParam)->isIntegerTy(32) ||
        FTy->getParamType(FstParam)->isIntegerTy(64))) &&
      (SndParam < 0 ||
       FTy->getParamType(SndParam)->isIntegerTy(32) ||
       FTy->getParamType(SndParam)->isIntegerTy(64)))
    return *FnData;
  return None;
}

/// DoPromotion - This method actually performs the promotion of the specified
/// arguments, and returns the new function.  At this point, we know that it's
/// safe to do so.
CallGraphNode *ArgPromotion::DoPromotion(Function *F,
                             SmallPtrSetImpl<Argument*> &ArgsToPromote,
                             SmallPtrSetImpl<Argument*> &ByValArgsToTransform) {

  // Start by computing a new prototype for the function, which is the same as
  // the old function, but has modified arguments.
  FunctionType *FTy = F->getFunctionType();
  std::vector<Type*> Params;

  typedef std::set<IndicesVector> ScalarizeTable;

  // ScalarizedElements - If we are promoting a pointer that has elements
  // accessed out of it, keep track of which elements are accessed so that we
  // can add one argument for each.
  //
  // Arguments that are directly loaded will have a zero element value here, to
  // handle cases where there are both a direct load and GEP accesses.
  //
  std::map<Argument*, ScalarizeTable> ScalarizedElements;

  // OriginalLoads - Keep track of a representative load instruction from the
  // original function so that we can tell the alias analysis implementation
  // what the new GEP/Load instructions we are inserting look like.
  // We need to keep the original loads for each argument and the elements
  // of the argument that are accessed.
  std::map<std::pair<Argument*, IndicesVector>, LoadInst*> OriginalLoads;

  // Attribute - Keep track of the parameter attributes for the arguments
  // that we are *not* promoting. For the ones that we do promote, the parameter
  // attributes are lost
  SmallVector<AttributeSet, 8> AttributesVec;
  const AttributeSet &PAL = F->getAttributes();

  // Add any return attributes.
  if (PAL.hasAttributes(AttributeSet::ReturnIndex))
    AttributesVec.push_back(AttributeSet::get(F->getContext(),
                                              PAL.getRetAttributes()));

  // First, determine the new argument list
  unsigned ArgIndex = 1;
  for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E;
       ++I, ++ArgIndex) {
    if (ByValArgsToTransform.count(I)) {
      // Simple byval argument? Just add all the struct element types.
      Type *AgTy = cast<PointerType>(I->getType())->getElementType();
      StructType *STy = cast<StructType>(AgTy);
      for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i)
        Params.push_back(STy->getElementType(i));
      ++NumByValArgsPromoted;
    } else if (!ArgsToPromote.count(I)) {
      // Unchanged argument
      Params.push_back(I->getType());
      AttributeSet attrs = PAL.getParamAttributes(ArgIndex);
      if (attrs.hasAttributes(ArgIndex)) {
        AttrBuilder B(attrs, ArgIndex);
        AttributesVec.
          push_back(AttributeSet::get(F->getContext(), Params.size(), B));
      }
    } else if (I->use_empty()) {
      // Dead argument (which are always marked as promotable)
      ++NumArgumentsDead;
    } else {
      // Okay, this is being promoted. This means that the only uses are loads
      // or GEPs which are only used by loads

      // In this table, we will track which indices are loaded from the argument
      // (where direct loads are tracked as no indices).
      ScalarizeTable &ArgIndices = ScalarizedElements[I];
      for (User *U : I->users()) {
        Instruction *UI = cast<Instruction>(U);
        assert(isa<LoadInst>(UI) || isa<GetElementPtrInst>(UI));
        IndicesVector Indices;
        Indices.reserve(UI->getNumOperands() - 1);
        // Since loads will only have a single operand, and GEPs only a single
        // non-index operand, this will record direct loads without any indices,
        // and gep+loads with the GEP indices.
        for (User::op_iterator II = UI->op_begin() + 1, IE = UI->op_end();
             II != IE; ++II)
          Indices.push_back(cast<ConstantInt>(*II)->getSExtValue());
        // GEPs with a single 0 index can be merged with direct loads
        if (Indices.size() == 1 && Indices.front() == 0)
          Indices.clear();
        ArgIndices.insert(Indices);
        LoadInst *OrigLoad;
        if (LoadInst *L = dyn_cast<LoadInst>(UI))
          OrigLoad = L;
        else
          // Take any load, we will use it only to update Alias Analysis
          OrigLoad = cast<LoadInst>(UI->user_back());
        OriginalLoads[std::make_pair(I, Indices)] = OrigLoad;
      }

      // Add a parameter to the function for each element passed in.
      for (ScalarizeTable::iterator SI = ArgIndices.begin(),
             E = ArgIndices.end(); SI != E; ++SI) {
        // not allowed to dereference ->begin() if size() is 0
        Params.push_back(GetElementPtrInst::getIndexedType(I->getType(), *SI));
//.........这里部分代码省略.........

bool TargetLibraryInfoImpl::isValidProtoForLibFunc(const FunctionType &FTy,
                                                   LibFunc::Func F,
                                                   const DataLayout *DL) const {
  LLVMContext &Ctx = FTy.getContext();
  Type *PCharTy = Type::getInt8PtrTy(Ctx);
  Type *SizeTTy = DL ? DL->getIntPtrType(Ctx, /*AS=*/0) : nullptr;
  auto IsSizeTTy = [SizeTTy](Type *Ty) {
    return SizeTTy ? Ty == SizeTTy : Ty->isIntegerTy();
  };
  unsigned NumParams = FTy.getNumParams();

  switch (F) {
  case LibFunc::strlen:
    return (NumParams == 1 && FTy.getParamType(0)->isPointerTy() &&
            FTy.getReturnType()->isIntegerTy());

  case LibFunc::strchr:
  case LibFunc::strrchr:
    return (NumParams == 2 && FTy.getReturnType()->isPointerTy() &&
            FTy.getParamType(0) == FTy.getReturnType() &&
            FTy.getParamType(1)->isIntegerTy());

  case LibFunc::strtol:
  case LibFunc::strtod:
  case LibFunc::strtof:
  case LibFunc::strtoul:
  case LibFunc::strtoll:
  case LibFunc::strtold:
  case LibFunc::strtoull:
    return ((NumParams == 2 || NumParams == 3) &&
            FTy.getParamType(0)->isPointerTy() &&
            FTy.getParamType(1)->isPointerTy());
  case LibFunc::strcat:
    return (NumParams == 2 && FTy.getReturnType()->isPointerTy() &&
            FTy.getParamType(0) == FTy.getReturnType() &&
            FTy.getParamType(1) == FTy.getReturnType());

  case LibFunc::strncat:
    return (NumParams == 3 && FTy.getReturnType()->isPointerTy() &&
            FTy.getParamType(0) == FTy.getReturnType() &&
            FTy.getParamType(1) == FTy.getReturnType() &&
            FTy.getParamType(2)->isIntegerTy());

  case LibFunc::strcpy_chk:
  case LibFunc::stpcpy_chk:
    --NumParams;
    if (!IsSizeTTy(FTy.getParamType(NumParams)))
      return false;
  // fallthrough
  case LibFunc::strcpy:
  case LibFunc::stpcpy:
    return (NumParams == 2 && FTy.getReturnType() == FTy.getParamType(0) &&
            FTy.getParamType(0) == FTy.getParamType(1) &&
            FTy.getParamType(0) == PCharTy);

  case LibFunc::strncpy_chk:
  case LibFunc::stpncpy_chk:
    --NumParams;
    if (!IsSizeTTy(FTy.getParamType(NumParams)))
      return false;
  // fallthrough
  case LibFunc::strncpy:
  case LibFunc::stpncpy:
    return (NumParams == 3 && FTy.getReturnType() == FTy.getParamType(0) &&
            FTy.getParamType(0) == FTy.getParamType(1) &&
            FTy.getParamType(0) == PCharTy &&
            FTy.getParamType(2)->isIntegerTy());

  case LibFunc::strxfrm:
    return (NumParams == 3 && FTy.getParamType(0)->isPointerTy() &&
            FTy.getParamType(1)->isPointerTy());

  case LibFunc::strcmp:
    return (NumParams == 2 && FTy.getReturnType()->isIntegerTy(32) &&
            FTy.getParamType(0)->isPointerTy() &&
            FTy.getParamType(0) == FTy.getParamType(1));

  case LibFunc::strncmp:
    return (NumParams == 3 && FTy.getReturnType()->isIntegerTy(32) &&
            FTy.getParamType(0)->isPointerTy() &&
            FTy.getParamType(0) == FTy.getParamType(1) &&
            FTy.getParamType(2)->isIntegerTy());

  case LibFunc::strspn:
  case LibFunc::strcspn:
    return (NumParams == 2 && FTy.getParamType(0)->isPointerTy() &&
            FTy.getParamType(0) == FTy.getParamType(1) &&
            FTy.getReturnType()->isIntegerTy());

  case LibFunc::strcoll:
  case LibFunc::strcasecmp:
  case LibFunc::strncasecmp:
    return (NumParams >= 2 && FTy.getParamType(0)->isPointerTy() &&
            FTy.getParamType(1)->isPointerTy());

  case LibFunc::strstr:
    return (NumParams == 2 && FTy.getReturnType()->isPointerTy() &&
            FTy.getParamType(0)->isPointerTy() &&
            FTy.getParamType(1)->isPointerTy());

//.........这里部分代码省略.........

/// Returns the allocation data for the given value if it's either a call to a
/// known allocation function, or a call to a function with the allocsize
/// attribute.
static Optional<AllocFnsTy> getAllocationData(const Value *V, AllocType AllocTy,
                                              const TargetLibraryInfo *TLI,
                                              bool LookThroughBitCast = false) {
  // Skip intrinsics
  if (isa<IntrinsicInst>(V))
    return None;

  const Function *Callee = getCalledFunction(V, LookThroughBitCast);
  if (!Callee)
    return None;

  // If it has allocsize, we can skip checking if it's a known function.
  //
  // MallocLike is chosen here because allocsize makes no guarantees about the
  // nullness of the result of the function, nor does it deal with strings, nor
  // does it require that the memory returned is zeroed out.
  LLVM_CONSTEXPR auto AllocSizeAllocTy = MallocLike;
  if ((AllocTy & AllocSizeAllocTy) == AllocSizeAllocTy &&
      Callee->hasFnAttribute(Attribute::AllocSize)) {
    Attribute Attr = Callee->getFnAttribute(Attribute::AllocSize);
    std::pair<unsigned, Optional<unsigned>> Args = Attr.getAllocSizeArgs();

    AllocFnsTy Result;
    Result.AllocTy = AllocSizeAllocTy;
    Result.NumParams = Callee->getNumOperands();
    Result.FstParam = Args.first;
    Result.SndParam = Args.second.getValueOr(-1);
    return Result;
  }

  // Make sure that the function is available.
  StringRef FnName = Callee->getName();
  LibFunc::Func TLIFn;
  if (!TLI || !TLI->getLibFunc(FnName, TLIFn) || !TLI->has(TLIFn))
    return None;

  const auto *Iter =
      std::find_if(std::begin(AllocationFnData), std::end(AllocationFnData),
                   [TLIFn](const std::pair<LibFunc::Func, AllocFnsTy> &P) {
                     return P.first == TLIFn;
                   });

  if (Iter == std::end(AllocationFnData))
    return None;

  const AllocFnsTy *FnData = &Iter->second;
  if ((FnData->AllocTy & AllocTy) != FnData->AllocTy)
    return None;

  // Check function prototype.
  int FstParam = FnData->FstParam;
  int SndParam = FnData->SndParam;
  FunctionType *FTy = Callee->getFunctionType();

  if (FTy->getReturnType() == Type::getInt8PtrTy(FTy->getContext()) &&
      FTy->getNumParams() == FnData->NumParams &&
      (FstParam < 0 ||
       (FTy->getParamType(FstParam)->isIntegerTy(32) ||
        FTy->getParamType(FstParam)->isIntegerTy(64))) &&
      (SndParam < 0 ||
       FTy->getParamType(SndParam)->isIntegerTy(32) ||
       FTy->getParamType(SndParam)->isIntegerTy(64)))
    return *FnData;
  return None;
}