private BinaryRelationship GetNormalizedRelationship(BoolConstraint boolConstraint, SymbolicValue leftOperand, SymbolicValue rightOperand)
{
var invertCount = 0;
var leftOp = leftOperand;
var logicalNotLeftOp = leftOp as LogicalNotSymbolicValue;
while (logicalNotLeftOp != null)
{
leftOp = logicalNotLeftOp.Operand;
logicalNotLeftOp = leftOp as LogicalNotSymbolicValue;
invertCount++;
}
var rightOp = rightOperand;
var logicalNotRightOp = rightOp as LogicalNotSymbolicValue;
while (logicalNotRightOp != null)
{
rightOp = logicalNotRightOp.Operand;
logicalNotRightOp = rightOp as LogicalNotSymbolicValue;
invertCount++;
}
var relationship = GetRelationship(boolConstraint, leftOp, rightOp);
return(invertCount % 2 == 0
? relationship
: relationship.Negate());
}
private BinaryRelationship GetRelationship(BoolConstraint boolConstraint, SymbolicValue left, SymbolicValue right)
{
var equalsRelationship = GetRelationship(left, right);
return(boolConstraint == BoolConstraint.True
? equalsRelationship
: equalsRelationship.Negate());
}
private BinaryRelationship GetRelationship(BoolConstraint boolConstraint)
{
var relationship = new ComparisonRelationship(this.comparisonKind, LeftOperand, RightOperand);
return(boolConstraint == BoolConstraint.True
? relationship
: relationship.Negate());
}
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)));
}
public override IEnumerable <ProgramState> TrySetConstraint(SymbolicValueConstraint constraint, ProgramState programState)
{
var boolConstraint = constraint as BoolConstraint;
if (boolConstraint == null)
{
return(new[] { programState });
}
SymbolicValueConstraints oldConstraints;
BoolConstraint oldBoolConstraint = null;
if (TryGetConstraints(programState, out oldConstraints))
{
oldBoolConstraint = oldConstraints.GetConstraintOrDefault <BoolConstraint>();
}
if (oldBoolConstraint != null /* could also be ObjectConstraint.NotNull, which can be overridden */ &&
oldBoolConstraint != boolConstraint)
{
return(Enumerable.Empty <ProgramState>());
}
SymbolicValueConstraints leftConstraints;
var leftHasConstraint = LeftOperand.TryGetConstraints(programState, out leftConstraints);
SymbolicValueConstraints rightConstraints;
var rightHasConstraint = RightOperand.TryGetConstraints(programState, out rightConstraints);
var relationship = GetRelationship(boolConstraint);
var newProgramState = programState.TrySetRelationship(relationship);
if (newProgramState == null)
{
return(Enumerable.Empty <ProgramState>());
}
if (!rightHasConstraint && !leftHasConstraint)
{
return(new[] { newProgramState });
}
return(SetConstraint(boolConstraint, leftConstraints, rightConstraints, newProgramState));
}
private IEnumerable <ProgramState> TrySetBoolConstraint(BoolConstraint constraint,
SymbolicValueConstraints oldConstraints, ProgramState programState)
{
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 != constraint)
{
return(Enumerable.Empty <ProgramState>());
}
// Either same bool constraint, or previously not null, and now a bool constraint
return(new[] { programState.SetConstraint(this, constraint) });
}
private BinaryRelationship GetRelationship(BoolConstraint boolConstraint)
{
return(GetNormalizedRelationship(boolConstraint, LeftOperand, RightOperand));
}
internal abstract IEnumerable <ProgramState> SetConstraint(BoolConstraint boolConstraint,
SymbolicValueConstraints leftConstraints, SymbolicValueConstraints rightConstraints,
ProgramState programState);
