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.");
// 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
}