ProgramStateRef ProgramState::assumeInBound(DefinedOrUnknownSVal Idx,
DefinedOrUnknownSVal UpperBound,
bool Assumption,
QualType indexTy) const {
if (Idx.isUnknown() || UpperBound.isUnknown())
return this;
// Build an expression for 0 <= Idx < UpperBound.
// This is the same as Idx + MIN < UpperBound + MIN, if overflow is allowed.
// FIXME: This should probably be part of SValBuilder.
ProgramStateManager &SM = getStateManager();
SValBuilder &svalBuilder = SM.getSValBuilder();
ASTContext &Ctx = svalBuilder.getContext();
// Get the offset: the minimum value of the array index type.
BasicValueFactory &BVF = svalBuilder.getBasicValueFactory();
// FIXME: This should be using ValueManager::ArrayindexTy...somehow.
if (indexTy.isNull())
indexTy = Ctx.IntTy;
nonloc::ConcreteInt Min(BVF.getMinValue(indexTy));
// Adjust the index.
SVal newIdx = svalBuilder.evalBinOpNN(this, BO_Add,
cast<NonLoc>(Idx), Min, indexTy);
if (newIdx.isUnknownOrUndef())
return this;
// Adjust the upper bound.
SVal newBound =
svalBuilder.evalBinOpNN(this, BO_Add, cast<NonLoc>(UpperBound),
Min, indexTy);
if (newBound.isUnknownOrUndef())
return this;
// Build the actual comparison.
SVal inBound = svalBuilder.evalBinOpNN(this, BO_LT,
cast<NonLoc>(newIdx), cast<NonLoc>(newBound),
Ctx.IntTy);
if (inBound.isUnknownOrUndef())
return this;
// Finally, let the constraint manager take care of it.
ConstraintManager &CM = SM.getConstraintManager();
return CM.assume(this, cast<DefinedSVal>(inBound), Assumption);
}
