ProgramStateRef SimpleConstraintManager::assumeInclusiveRange(
ProgramStateRef State, NonLoc Value, const llvm::APSInt &From,
const llvm::APSInt &To, bool InRange) {
assert(From.isUnsigned() == To.isUnsigned() &&
From.getBitWidth() == To.getBitWidth() &&
"Values should have same types!");
if (!canReasonAbout(Value)) {
// Just add the constraint to the expression without trying to simplify.
SymbolRef Sym = Value.getAsSymExpr();
assert(Sym);
return assumeSymWithinInclusiveRange(State, Sym, From, To, InRange);
}
switch (Value.getSubKind()) {
default:
llvm_unreachable("'assumeInclusiveRange' is not implemented"
"for this NonLoc");
case nonloc::LocAsIntegerKind:
case nonloc::SymbolValKind: {
if (SymbolRef Sym = Value.getAsSymbol())
return assumeSymWithinInclusiveRange(State, Sym, From, To, InRange);
return State;
} // end switch
case nonloc::ConcreteIntKind: {
const llvm::APSInt &IntVal = Value.castAs<nonloc::ConcreteInt>().getValue();
bool IsInRange = IntVal >= From && IntVal <= To;
bool isFeasible = (IsInRange == InRange);
return isFeasible ? State : nullptr;
}
} // end switch
}
ProgramStateRef
BasicConstraintManager::assumeSymLE(ProgramStateRef state,
SymbolRef sym,
const llvm::APSInt &V,
const llvm::APSInt &Adjustment) {
// Reject a path if the value of sym is a constant X and !(X+Adj <= V).
if (const llvm::APSInt* X = getSymVal(state, sym)) {
bool isFeasible = (*X <= V-Adjustment);
return isFeasible ? state : NULL;
}
// Sym is not a constant, but it is worth looking to see if V is the
// minimum integer value.
if (V == llvm::APSInt::getMinValue(V.getBitWidth(), V.isUnsigned())) {
llvm::APSInt Adjusted = V-Adjustment;
// If we know that sym != V (after adjustment), then this condition
// is infeasible since there is no other value less than V.
bool isFeasible = !isNotEqual(state, sym, Adjusted);
// If the path is still feasible then as a consequence we know that
// 'sym+Adjustment == V' because there are no smaller values.
// Add this constraint.
return isFeasible ? AddEQ(state, sym, Adjusted) : NULL;
}
return state;
}
ProgramStateRef
BasicConstraintManager::assumeSymGT(ProgramStateRef state,
SymbolRef sym,
const llvm::APSInt &V,
const llvm::APSInt &Adjustment) {
// Is 'V' the largest possible value?
if (V == llvm::APSInt::getMaxValue(V.getBitWidth(), V.isUnsigned())) {
// sym cannot be any value greater than 'V'. This path is infeasible.
return NULL;
}
// FIXME: For now have assuming x > y be the same as assuming sym != V;
return assumeSymNE(state, sym, V, Adjustment);
}
TemplateArgument::TemplateArgument(ASTContext &Ctx, const llvm::APSInt &Value,
QualType Type) {
Integer.Kind = Integral;
// Copy the APSInt value into our decomposed form.
Integer.BitWidth = Value.getBitWidth();
Integer.IsUnsigned = Value.isUnsigned();
// If the value is large, we have to get additional memory from the ASTContext
unsigned NumWords = Value.getNumWords();
if (NumWords > 1) {
void *Mem = Ctx.Allocate(NumWords * sizeof(uint64_t));
std::memcpy(Mem, Value.getRawData(), NumWords * sizeof(uint64_t));
Integer.pVal = static_cast<uint64_t *>(Mem);
} else {
Integer.VAL = Value.getZExtValue();
}
Integer.Type = Type.getAsOpaquePtr();
}
/// \brief Determine if two APSInts have the same value, zero- or sign-extending
/// as needed.
static bool IsSameValue(const llvm::APSInt &I1, const llvm::APSInt &I2) {
if (I1.getBitWidth() == I2.getBitWidth() && I1.isSigned() == I2.isSigned())
return I1 == I2;
// Check for a bit-width mismatch.
if (I1.getBitWidth() > I2.getBitWidth())
return IsSameValue(I1, I2.extend(I1.getBitWidth()));
else if (I2.getBitWidth() > I1.getBitWidth())
return IsSameValue(I1.extend(I2.getBitWidth()), I2);
// We have a signedness mismatch. Turn the signed value into an unsigned
// value.
if (I1.isSigned()) {
if (I1.isNegative())
return false;
return llvm::APSInt(I1, true) == I2;
}
if (I2.isNegative())
return false;
return I1 == llvm::APSInt(I2, true);
}
SVal SimpleSValBuilder::MakeSymIntVal(const SymExpr *LHS,
BinaryOperator::Opcode op,
const llvm::APSInt &RHS,
QualType resultTy) {
bool isIdempotent = false;
// Check for a few special cases with known reductions first.
switch (op) {
default:
// We can't reduce this case; just treat it normally.
break;
case BO_Mul:
// a*0 and a*1
if (RHS == 0)
return makeIntVal(0, resultTy);
else if (RHS == 1)
isIdempotent = true;
break;
case BO_Div:
// a/0 and a/1
if (RHS == 0)
// This is also handled elsewhere.
return UndefinedVal();
else if (RHS == 1)
isIdempotent = true;
break;
case BO_Rem:
// a%0 and a%1
if (RHS == 0)
// This is also handled elsewhere.
return UndefinedVal();
else if (RHS == 1)
return makeIntVal(0, resultTy);
break;
case BO_Add:
case BO_Sub:
case BO_Shl:
case BO_Shr:
case BO_Xor:
// a+0, a-0, a<<0, a>>0, a^0
if (RHS == 0)
isIdempotent = true;
break;
case BO_And:
// a&0 and a&(~0)
if (RHS == 0)
return makeIntVal(0, resultTy);
else if (RHS.isAllOnesValue())
isIdempotent = true;
break;
case BO_Or:
// a|0 and a|(~0)
if (RHS == 0)
isIdempotent = true;
else if (RHS.isAllOnesValue()) {
const llvm::APSInt &Result = BasicVals.Convert(resultTy, RHS);
return nonloc::ConcreteInt(Result);
}
break;
}
// Idempotent ops (like a*1) can still change the type of an expression.
// Wrap the LHS up in a NonLoc again and let evalCastFromNonLoc do the
// dirty work.
if (isIdempotent)
return evalCastFromNonLoc(nonloc::SymbolVal(LHS), resultTy);
// If we reach this point, the expression cannot be simplified.
// Make a SymbolVal for the entire expression, after converting the RHS.
const llvm::APSInt *ConvertedRHS = &RHS;
if (BinaryOperator::isComparisonOp(op)) {
// We're looking for a type big enough to compare the symbolic value
// with the given constant.
// FIXME: This is an approximation of Sema::UsualArithmeticConversions.
ASTContext &Ctx = getContext();
QualType SymbolType = LHS->getType();
uint64_t ValWidth = RHS.getBitWidth();
uint64_t TypeWidth = Ctx.getTypeSize(SymbolType);
if (ValWidth < TypeWidth) {
// If the value is too small, extend it.
ConvertedRHS = &BasicVals.Convert(SymbolType, RHS);
} else if (ValWidth == TypeWidth) {
// If the value is signed but the symbol is unsigned, do the comparison
// in unsigned space. [C99 6.3.1.8]
// (For the opposite case, the value is already unsigned.)
if (RHS.isSigned() && !SymbolType->isSignedIntegerOrEnumerationType())
ConvertedRHS = &BasicVals.Convert(SymbolType, RHS);
}
} else
ConvertedRHS = &BasicVals.Convert(resultTy, RHS);
return makeNonLoc(LHS, op, *ConvertedRHS, resultTy);
}
unsigned getBitWidth() const { return Val.getBitWidth(); }