C++ APSIntType类代码示例

/// 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());
}

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);
}

ProgramStateRef SimpleConstraintManager::assumeSymRel(ProgramStateRef state,
                                                     const SymExpr *LHS,
                                                     BinaryOperator::Opcode op,
                                                     const llvm::APSInt& Int) {
  assert(BinaryOperator::isComparisonOp(op) &&
         "Non-comparison ops should be rewritten as comparisons to zero.");

  BasicValueFactory &BVF = getBasicVals();
  ASTContext &Ctx = BVF.getContext();

  // Get the type used for calculating wraparound.
  APSIntType WraparoundType = BVF.getAPSIntType(LHS->getType(Ctx));

  // We only handle simple comparisons of the form "$sym == constant"
  // or "($sym+constant1) == constant2".
  // The adjustment is "constant1" in the above expression. It's used to
  // "slide" the solution range around for modular arithmetic. For example,
  // x < 4 has the solution [0, 3]. x+2 < 4 has the solution [0-2, 3-2], which
  // in modular arithmetic is [0, 1] U [UINT_MAX-1, UINT_MAX]. It's up to
  // the subclasses of SimpleConstraintManager to handle the adjustment.
  SymbolRef Sym = LHS;
  llvm::APSInt Adjustment = WraparoundType.getZeroValue();
  computeAdjustment(Sym, Adjustment);

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

  switch (op) {
  default:
    // No logic yet for other operators.  assume the constraint is feasible.
    return state;

  case BO_EQ:
    return assumeSymEQ(state, Sym, ConvertedInt, Adjustment);

  case BO_NE:
    return assumeSymNE(state, Sym, ConvertedInt, Adjustment);

  case BO_GT:
    return assumeSymGT(state, Sym, ConvertedInt, Adjustment);

  case BO_GE:
    return assumeSymGE(state, Sym, ConvertedInt, Adjustment);

  case BO_LT:
    return assumeSymLT(state, Sym, ConvertedInt, Adjustment);

  case BO_LE:
    return assumeSymLE(state, Sym, ConvertedInt, Adjustment);
  } // end switch
}

ProgramStateRef SimpleConstraintManager::assumeSymRel(ProgramStateRef State,
                                                      const SymExpr *LHS,
                                                      BinaryOperator::Opcode Op,
                                                      const llvm::APSInt &Int) {
  assert(BinaryOperator::isComparisonOp(Op) &&
         "Non-comparison ops should be rewritten as comparisons to zero.");

  // Get the type used for calculating wraparound.
  BasicValueFactory &BVF = getBasicVals();
  APSIntType WraparoundType = BVF.getAPSIntType(LHS->getType());

  // We only handle simple comparisons of the form "$sym == constant"
  // or "($sym+constant1) == constant2".
  // The adjustment is "constant1" in the above expression. It's used to
  // "slide" the solution range around for modular arithmetic. For example,
  // x < 4 has the solution [0, 3]. x+2 < 4 has the solution [0-2, 3-2], which
  // in modular arithmetic is [0, 1] U [UINT_MAX-1, UINT_MAX]. It's up to
  // the subclasses of SimpleConstraintManager to handle the adjustment.
  SymbolRef Sym = LHS;
  llvm::APSInt Adjustment = WraparoundType.getZeroValue();
  computeAdjustment(Sym, Adjustment);

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

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

  switch (Op) {
  default:
    llvm_unreachable("invalid operation not caught by assertion above");

  case BO_EQ:
    return assumeSymEQ(State, Sym, ConvertedInt, Adjustment);

  case BO_NE:
    return assumeSymNE(State, Sym, ConvertedInt, Adjustment);

  case BO_GT:
    return assumeSymGT(State, Sym, ConvertedInt, Adjustment);

  case BO_GE:
    return assumeSymGE(State, Sym, ConvertedInt, Adjustment);

  case BO_LT:
    return assumeSymLT(State, Sym, ConvertedInt, Adjustment);

  case BO_LE:
    return assumeSymLE(State, Sym, ConvertedInt, Adjustment);
  } // end switch
}

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;
}

ConditionTruthVal RangeConstraintManager::checkNull(ProgramStateRef State,
                                                    SymbolRef Sym) {
  const RangeSet *Ranges = State->get<ConstraintRange>(Sym);

  // If we don't have any information about this symbol, it's underconstrained.
  if (!Ranges)
    return ConditionTruthVal();

  // If we have a concrete value, see if it's zero.
  if (const llvm::APSInt *Value = Ranges->getConcreteValue())
    return *Value == 0;

  BasicValueFactory &BV = getBasicVals();
  APSIntType IntType = BV.getAPSIntType(Sym->getType());
  llvm::APSInt Zero = IntType.getZeroValue();

  // Check if zero is in the set of possible values.
  if (Ranges->Intersect(BV, F, Zero, Zero).isEmpty())
    return false;

  // Zero is a possible value, but it is not the /only/ possible value.
  return ConditionTruthVal();
}

SVal SimpleSValBuilder::evalBinOpNN(ProgramStateRef state,
                                  BinaryOperator::Opcode op,
                                  NonLoc lhs, NonLoc rhs,
                                  QualType resultTy)  {
  NonLoc InputLHS = lhs;
  NonLoc InputRHS = rhs;

  // Handle trivial case where left-side and right-side are the same.
  if (lhs == rhs)
    switch (op) {
      default:
        break;
      case BO_EQ:
      case BO_LE:
      case BO_GE:
        return makeTruthVal(true, resultTy);
      case BO_LT:
      case BO_GT:
      case BO_NE:
        return makeTruthVal(false, resultTy);
      case BO_Xor:
      case BO_Sub:
        if (resultTy->isIntegralOrEnumerationType())
          return makeIntVal(0, resultTy);
        return evalCastFromNonLoc(makeIntVal(0, /*Unsigned=*/false), resultTy);
      case BO_Or:
      case BO_And:
        return evalCastFromNonLoc(lhs, resultTy);
    }

  while (1) {
    switch (lhs.getSubKind()) {
    default:
      return makeSymExprValNN(state, op, lhs, rhs, resultTy);
    case nonloc::PointerToMemberKind: {
      assert(rhs.getSubKind() == nonloc::PointerToMemberKind &&
             "Both SVals should have pointer-to-member-type");
      auto LPTM = lhs.castAs<nonloc::PointerToMember>(),
           RPTM = rhs.castAs<nonloc::PointerToMember>();
      auto LPTMD = LPTM.getPTMData(), RPTMD = RPTM.getPTMData();
      switch (op) {
        case BO_EQ:
          return makeTruthVal(LPTMD == RPTMD, resultTy);
        case BO_NE:
          return makeTruthVal(LPTMD != RPTMD, resultTy);
        default:
          return UnknownVal();
      }
    }
    case nonloc::LocAsIntegerKind: {
      Loc lhsL = lhs.castAs<nonloc::LocAsInteger>().getLoc();
      switch (rhs.getSubKind()) {
        case nonloc::LocAsIntegerKind:
          return evalBinOpLL(state, op, lhsL,
                             rhs.castAs<nonloc::LocAsInteger>().getLoc(),
                             resultTy);
        case nonloc::ConcreteIntKind: {
          // Transform the integer into a location and compare.
          // FIXME: This only makes sense for comparisons. If we want to, say,
          // add 1 to a LocAsInteger, we'd better unpack the Loc and add to it,
          // then pack it back into a LocAsInteger.
          llvm::APSInt i = rhs.castAs<nonloc::ConcreteInt>().getValue();
          BasicVals.getAPSIntType(Context.VoidPtrTy).apply(i);
          return evalBinOpLL(state, op, lhsL, makeLoc(i), resultTy);
        }
        default:
          switch (op) {
            case BO_EQ:
              return makeTruthVal(false, resultTy);
            case BO_NE:
              return makeTruthVal(true, resultTy);
            default:
              // This case also handles pointer arithmetic.
              return makeSymExprValNN(state, op, InputLHS, InputRHS, resultTy);
          }
      }
    }
    case nonloc::ConcreteIntKind: {
      llvm::APSInt LHSValue = lhs.castAs<nonloc::ConcreteInt>().getValue();

      // If we're dealing with two known constants, just perform the operation.
      if (const llvm::APSInt *KnownRHSValue = getKnownValue(state, rhs)) {
        llvm::APSInt RHSValue = *KnownRHSValue;
        if (BinaryOperator::isComparisonOp(op)) {
          // We're looking for a type big enough to compare the two values.
          // FIXME: This is not correct. char + short will result in a promotion
          // to int. Unfortunately we have lost types by this point.
          APSIntType CompareType = std::max(APSIntType(LHSValue),
                                            APSIntType(RHSValue));
          CompareType.apply(LHSValue);
          CompareType.apply(RHSValue);
        } else if (!BinaryOperator::isShiftOp(op)) {
          APSIntType IntType = BasicVals.getAPSIntType(resultTy);
          IntType.apply(LHSValue);
          IntType.apply(RHSValue);
        }

        const llvm::APSInt *Result =
          BasicVals.evalAPSInt(op, LHSValue, RHSValue);
        if (!Result)
//.........这里部分代码省略.........