C++ SymbolRef::getType方法代码示例

/// CastRetrievedVal - Used by subclasses of StoreManager to implement
///  implicit casts that arise from loads from regions that are reinterpreted
///  as another region.
SVal StoreManager::CastRetrievedVal(SVal V, const TypedValueRegion *R,
                                    QualType castTy) {
  if (castTy.isNull() || V.isUnknownOrUndef())
    return V;

  // The dispatchCast() call below would convert the int into a float.
  // What we want, however, is a bit-by-bit reinterpretation of the int
  // as a float, which usually yields nothing garbage. For now skip casts
  // from ints to floats.
  // TODO: What other combinations of types are affected?
  if (castTy->isFloatingType()) {
    SymbolRef Sym = V.getAsSymbol();
    if (Sym && !Sym->getType()->isFloatingType())
      return UnknownVal();
  }

  // When retrieving symbolic pointer and expecting a non-void pointer,
  // wrap them into element regions of the expected type if necessary.
  // SValBuilder::dispatchCast() doesn't do that, but it is necessary to
  // make sure that the retrieved value makes sense, because there's no other
  // cast in the AST that would tell us to cast it to the correct pointer type.
  // We might need to do that for non-void pointers as well.
  // FIXME: We really need a single good function to perform casts for us
  // correctly every time we need it.
  if (castTy->isPointerType() && !castTy->isVoidPointerType())
    if (const auto *SR = dyn_cast_or_null<SymbolicRegion>(V.getAsRegion()))
      if (SR->getSymbol()->getType().getCanonicalType() !=
          castTy.getCanonicalType())
        return loc::MemRegionVal(castRegion(SR, castTy));

  return svalBuilder.dispatchCast(V, castTy);
}

    explicit symbol(const SymbolRef& sym) {
        StringRef name;
        if(error_code err = sym.getName(name))
            llvm_binary_fail(err);
        this->name_ = name.str();

        if (error_code err = sym.getType(this->kind_))
            llvm_binary_fail(err);

        if (error_code err = sym.getAddress(this->addr_))
            llvm_binary_fail(err);

        if (error_code err = sym.getSize(this->size_))
            llvm_binary_fail(err);

        uint32_t flags;
        if (error_code err = sym.getFlags(flags))
            llvm_binary_fail(err);

        if (flags & SymbolRef::SF_Undefined) {
            uint64_t addr;
            if (error_code err = sym.getValue(addr))
                llvm_binary_fail(err);
            // This will not work for x86-64, since they usually zero
            // the value. BFD library uses index correspondence
            // between plt entry and relocation, to name the plt
            // entry. We can't afford this.
            if (addr) {
                addr_ = addr;
                size_ = 8;
            }
        }
    }

  bool operator()(const SymbolRef &A, const SymbolRef &B) {
    SymbolRef::Type AType, BType;
    A.getType(AType);
    B.getType(BType);

    uint64_t AAddr, BAddr;
    if (AType != SymbolRef::ST_Function)
      AAddr = 0;
    else
      A.getAddress(AAddr);
    if (BType != SymbolRef::ST_Function)
      BAddr = 0;
    else
      B.getAddress(BAddr);
    return AAddr < BAddr;
  }

ProgramStateRef SimpleConstraintManager::assumeSymWithinInclusiveRange(
    ProgramStateRef State, SymbolRef Sym, const llvm::APSInt &From,
    const llvm::APSInt &To, bool InRange) {
  // Get the type used for calculating wraparound.
  BasicValueFactory &BVF = getBasicVals();
  APSIntType WraparoundType = BVF.getAPSIntType(Sym->getType());

  llvm::APSInt Adjustment = WraparoundType.getZeroValue();
  SymbolRef AdjustedSym = Sym;
  computeAdjustment(AdjustedSym, Adjustment);

  // Convert the right-hand side integer as necessary.
  APSIntType ComparisonType = std::max(WraparoundType, APSIntType(From));
  llvm::APSInt ConvertedFrom = ComparisonType.convert(From);
  llvm::APSInt ConvertedTo = ComparisonType.convert(To);

  // Prefer unsigned comparisons.
  if (ComparisonType.getBitWidth() == WraparoundType.getBitWidth() &&
      ComparisonType.isUnsigned() && !WraparoundType.isUnsigned())
    Adjustment.setIsSigned(false);

  if (InRange)
    return assumeSymbolWithinInclusiveRange(State, AdjustedSym, ConvertedFrom,
                                            ConvertedTo, Adjustment);
  return assumeSymbolOutOfInclusiveRange(State, AdjustedSym, ConvertedFrom,
                                         ConvertedTo, Adjustment);
}

RangeSet RangeConstraintManager::getRange(ProgramStateRef State,
                                          SymbolRef Sym) {
  if (ConstraintRangeTy::data_type *V = State->get<ConstraintRange>(Sym))
    return *V;

  BasicValueFactory &BV = getBasicVals();

  // If Sym is a difference of symbols A - B, then maybe we have range set
  // stored for B - A.
  if (const RangeSet *R = getRangeForMinusSymbol(State, Sym))
    return R->Negate(BV, F);

  // Lazily generate a new RangeSet representing all possible values for the
  // given symbol type.
  QualType T = Sym->getType();

  RangeSet Result(F, BV.getMinValue(T), BV.getMaxValue(T));

  // References are known to be non-zero.
  if (T->isReferenceType())
    return assumeNonZero(BV, F, Sym, Result);

  // Known constraints on ranges of bitwise expressions.
  if (const SymIntExpr* SIE = dyn_cast<SymIntExpr>(Sym))
    return applyBitwiseConstraints(BV, F, Result, SIE);

  return Result;
}

static const MemRegion *unwrapRValueReferenceIndirection(const MemRegion *MR) {
  if (const auto *SR = dyn_cast_or_null<SymbolicRegion>(MR)) {
    SymbolRef Sym = SR->getSymbol();
    if (Sym->getType()->isRValueReferenceType())
      if (const MemRegion *OriginMR = Sym->getOriginRegion())
        return OriginMR;
  }
  return MR;
}

/// Return a range set subtracting zero from \p Domain.
static RangeSet assumeNonZero(
    BasicValueFactory &BV,
    RangeSet::Factory &F,
    SymbolRef Sym,
    RangeSet Domain) {
  APSIntType IntType = BV.getAPSIntType(Sym->getType());
  return Domain.Intersect(BV, F, ++IntType.getZeroValue(),
      --IntType.getZeroValue());
}

ConditionTruthVal ConstraintManager::checkNull(ProgramStateRef State,
                                               SymbolRef Sym) {
  QualType Ty = Sym->getType();
  DefinedSVal V = Loc::isLocType(Ty) ? getLocFromSymbol(State, Sym)
                                     : nonloc::SymbolVal(Sym);
  const ProgramStatePair &P = assumeDual(State, V);
  if (P.first && !P.second)
    return ConditionTruthVal(false);
  if (!P.first && P.second)
    return ConditionTruthVal(true);
  return ConditionTruthVal();
}

 explicit symbol(const SymbolRef& sym) {
     StringRef name;
     if(error_code err = sym.getName(name))
         llvm_binary_fail(err);
     this->name_ = name.str();
     
     if (error_code err = sym.getType(this->kind_))
         llvm_binary_fail(err);
     
     if (error_code err = sym.getAddress(this->addr_))
         llvm_binary_fail(err);
     
     if (error_code err = sym.getSize(this->size_))
         llvm_binary_fail(err);
 }

ProgramStateRef
SimpleConstraintManager::assumeAuxForSymbol(ProgramStateRef State,
                                            SymbolRef Sym, bool Assumption) {
  BasicValueFactory &BVF = getBasicVals();
  QualType T = Sym->getType();

  // None of the constraint solvers currently support non-integer types.
  if (!T->isIntegralOrEnumerationType())
    return State;

  const llvm::APSInt &zero = BVF.getValue(0, T);
  if (Assumption)
    return assumeSymNE(State, Sym, zero, zero);
  else
    return assumeSymEQ(State, Sym, zero, zero);
}

ProgramStateRef
RangedConstraintManager::assumeSymUnsupported(ProgramStateRef State,
                                              SymbolRef Sym, bool Assumption) {
  BasicValueFactory &BVF = getBasicVals();
  QualType T = Sym->getType();

  // Non-integer types are not supported.
  if (!T->isIntegralOrEnumerationType())
    return State;

  // Reverse the operation and add directly to state.
  const llvm::APSInt &Zero = BVF.getValue(0, T);
  if (Assumption)
    return assumeSymNE(State, Sym, Zero, Zero);
  else
    return assumeSymEQ(State, Sym, Zero, Zero);
}

DynamicTypeInfo ProgramState::getDynamicTypeInfo(const MemRegion *Reg) const {
  Reg = Reg->StripCasts();

  // Look up the dynamic type in the GDM.
  const DynamicTypeInfo *GDMType = get<DynamicTypeMap>(Reg);
  if (GDMType)
    return *GDMType;

  // Otherwise, fall back to what we know about the region.
  if (const TypedRegion *TR = dyn_cast<TypedRegion>(Reg))
    return DynamicTypeInfo(TR->getLocationType(), /*CanBeSubclass=*/false);

  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(Reg)) {
    SymbolRef Sym = SR->getSymbol();
    return DynamicTypeInfo(Sym->getType(getStateManager().getContext()));
  }

  return DynamicTypeInfo();
}

DynamicTypeInfo getDynamicTypeInfo(ProgramStateRef State,
                                   const MemRegion *Reg) {
  Reg = Reg->StripCasts();

  // Look up the dynamic type in the GDM.
  const DynamicTypeInfo *GDMType = State->get<DynamicTypeMap>(Reg);
  if (GDMType)
    return *GDMType;

  // Otherwise, fall back to what we know about the region.
  if (const auto *TR = dyn_cast<TypedRegion>(Reg))
    return DynamicTypeInfo(TR->getLocationType(), /*CanBeSubclass=*/false);

  if (const auto *SR = dyn_cast<SymbolicRegion>(Reg)) {
    SymbolRef Sym = SR->getSymbol();
    return DynamicTypeInfo(Sym->getType());
  }

  return {};
}

RangeSet
RangeConstraintManager::GetRange(ProgramStateRef state, SymbolRef sym) {
  if (ConstraintRangeTy::data_type* V = state->get<ConstraintRange>(sym))
    return *V;

  // Lazily generate a new RangeSet representing all possible values for the
  // given symbol type.
  BasicValueFactory &BV = getBasicVals();
  QualType T = sym->getType();

  RangeSet Result(F, BV.getMinValue(T), BV.getMaxValue(T));

  // Special case: references are known to be non-zero.
  if (T->isReferenceType()) {
    APSIntType IntType = BV.getAPSIntType(T);
    Result = Result.Intersect(BV, F, ++IntType.getZeroValue(),
                                     --IntType.getZeroValue());
  }

  return Result;
}

std::error_code SymbolizableObjectFile::addSymbol(const SymbolRef &Symbol,
                                                  uint64_t SymbolSize,
                                                  DataExtractor *OpdExtractor,
                                                  uint64_t OpdAddress) {
  ErrorOr<SymbolRef::Type> SymbolTypeOrErr = Symbol.getType();
  if (auto EC = SymbolTypeOrErr.getError())
    return EC;
  SymbolRef::Type SymbolType = *SymbolTypeOrErr;
  if (SymbolType != SymbolRef::ST_Function && SymbolType != SymbolRef::ST_Data)
    return std::error_code();
  ErrorOr<uint64_t> SymbolAddressOrErr = Symbol.getAddress();
  if (auto EC = SymbolAddressOrErr.getError())
    return EC;
  uint64_t SymbolAddress = *SymbolAddressOrErr;
  if (OpdExtractor) {
    // For big-endian PowerPC64 ELF, symbols in the .opd section refer to
    // function descriptors. The first word of the descriptor is a pointer to
    // the function's code.
    // For the purposes of symbolization, pretend the symbol's address is that
    // of the function's code, not the descriptor.
    uint64_t OpdOffset = SymbolAddress - OpdAddress;
    uint32_t OpdOffset32 = OpdOffset;
    if (OpdOffset == OpdOffset32 && 
        OpdExtractor->isValidOffsetForAddress(OpdOffset32))
      SymbolAddress = OpdExtractor->getAddress(&OpdOffset32);
  }
  Expected<StringRef> SymbolNameOrErr = Symbol.getName();
  if (!SymbolNameOrErr)
    return errorToErrorCode(SymbolNameOrErr.takeError());
  StringRef SymbolName = *SymbolNameOrErr;
  // Mach-O symbol table names have leading underscore, skip it.
  if (Module->isMachO() && SymbolName.size() > 0 && SymbolName[0] == '_')
    SymbolName = SymbolName.drop_front();
  // FIXME: If a function has alias, there are two entries in symbol table
  // with same address size. Make sure we choose the correct one.
  auto &M = SymbolType == SymbolRef::ST_Function ? Functions : Objects;
  SymbolDesc SD = { SymbolAddress, SymbolSize };
  M.insert(std::make_pair(SD, SymbolName));
  return std::error_code();
}