private IEnumerable <ProgramState> TrySetConstraint(ObjectConstraint objectConstraint,
SymbolicValueConstraints oldConstraints, ProgramState currentProgramState)
{
var oldBoolConstraint = oldConstraints.GetConstraintOrDefault <BoolConstraint>();
if (oldBoolConstraint != null)
{
if (objectConstraint == ObjectConstraint.Null)
{
return(Enumerable.Empty <ProgramState>());
}
return(new[] { currentProgramState });
}
var oldObjectConstraint = oldConstraints.GetConstraintOrDefault <ObjectConstraint>();
if (oldObjectConstraint != null)
{
if (oldObjectConstraint != objectConstraint)
{
return(Enumerable.Empty <ProgramState>());
}
return(new[] { SetConstraint(objectConstraint, currentProgramState) });
}
throw new NotSupportedException($"Neither {nameof(BoolConstraint)}, nor {nameof(ObjectConstraint)}");
}
private ImmutableDictionary <SymbolicValue, SymbolicValueConstraints> AddConstraintForSymbolicValue(SymbolicValue symbolicValue,
SymbolicValueConstraint constraint, ImmutableDictionary <SymbolicValue, SymbolicValueConstraints> constraintMap)
{
var constraints = constraintMap.GetValueOrDefault(symbolicValue);
var updatedConstraints = constraints != null
? constraints.WithConstraint(constraint)
: SymbolicValueConstraints.Create(constraint);
return(constraintMap.SetItem(symbolicValue, updatedConstraints));
}
internal override IEnumerable <ProgramState> SetConstraint(BoolConstraint boolConstraint,
SymbolicValueConstraints leftConstraints, SymbolicValueConstraints rightConstraints,
ProgramState programState)
{
if (boolConstraint == BoolConstraint.False)
{
return(RightOperand.TrySetConstraints(leftConstraints, programState)
.SelectMany(ps => LeftOperand.TrySetConstraints(rightConstraints, ps)));
}
return(RightOperand.TrySetOppositeConstraints(leftConstraints, programState)
.SelectMany(ps => LeftOperand.TrySetOppositeConstraints(rightConstraints, ps)));
}
private IEnumerable <ProgramState> TrySetConstraint(BoolConstraint boolConstraint,
SymbolicValueConstraints oldConstraints, ProgramState currentProgramState)
{
if (oldConstraints.HasConstraint(ObjectConstraint.Null))
{
// It was null, and now it should be true or false
return(Enumerable.Empty <ProgramState>());
}
var oldBoolConstraint = oldConstraints.GetConstraintOrDefault <BoolConstraint>();
if (oldBoolConstraint != null &&
oldBoolConstraint != boolConstraint)
{
return(Enumerable.Empty <ProgramState>());
}
// Either same bool constraint, or previously not null, and now a bool constraint
return(new[] { SetConstraint(boolConstraint, currentProgramState) });
}
private IEnumerable <ProgramState> TrySetConstraints(SymbolicValueConstraints constraints,
ProgramState programState, bool isOppositeConstraints)
{
IEnumerable <ProgramState> programStates = new [] { programState };
if (constraints == null)
{
return(programStates);
}
foreach (var constraint in constraints.GetConstraints())
{
programStates = programStates.SelectMany(ps =>
isOppositeConstraints
? TrySetOppositeConstraint(constraint, ps)
: TrySetConstraint(constraint, ps));
}
return(programStates);
}
public IEnumerable <ProgramState> TrySetOppositeConstraints(SymbolicValueConstraints constraints,
ProgramState programState)
{
return(TrySetConstraints(constraints, programState, true));
}
public bool TryGetConstraints(ProgramState programState, out SymbolicValueConstraints constraints)
{
return(programState.Constraints.TryGetValue(this, out constraints));
}
internal abstract IEnumerable <ProgramState> SetConstraint(BoolConstraint boolConstraint,
SymbolicValueConstraints leftConstraints, SymbolicValueConstraints rightConstraints,
ProgramState programState);