protected override void OnBeforePathStepExtended(FlowEdge edge)
{
this.smtSolver.Push();
this.Heap.PushState();
if (edge is OuterFlowEdge outerEdge)
{
if (outerEdge.Kind == OuterFlowEdgeKind.MethodCall &&
outerEdge.To is EnterFlowNode enterNode)
{
var callNode = (CallFlowNode)outerEdge.From;
if (callNode.IsObjectCreation)
{
// This is needed in the case when the exploration itself started from a constructor (or from a
// method called by it). We need to let the heap know that this object is not a part of the input
// heap.
var newVar = enterNode.Parameters[0];
var versionedVar = new VersionedVariable(newVar, this.GetVariableVersion(newVar));
this.Heap.AllocateNew(versionedVar);
}
else if (callNode.IsInstanceCall)
{
var thisVar = enterNode.Parameters[0];
var versionedThisVar = new VersionedVariable(thisVar, this.GetVariableVersion(thisVar));
this.Heap.AssertEquality(false, versionedThisVar, VersionedVariable.Null);
}
}
}
}
protected override void OnFieldReadAsserted(
VersionedVariable result,
VersionedVariable reference,
IFieldDefinition field)
{
this.Heap.ReadField(result, reference, field);
}
protected override void OnFieldWriteAsserted(
VersionedVariable reference,
IFieldDefinition field,
Expression value)
{
this.Heap.WriteField(reference, field, value);
}
protected override void OnReferenceEqualityAsserted(
bool areEqual,
VersionedVariable left,
VersionedVariable right)
{
this.Heap.AssertEquality(areEqual, left, right);
}
protected override void OnFieldReadRetracted(
VersionedVariable result,
VersionedVariable reference,
IFieldDefinition field)
{
this.heapModelRecorder.ReadField(reference, field);
this.AddVariableValue(result);
}
private void AddVariableValue(VersionedVariable variable)
{
if (variable.Variable.IsReference)
{
this.AddVariableHeapLocation(variable);
}
else
{
this.AddVariableInterpretation(variable);
}
}
protected override void OnReferenceEqualityRetracted(
bool areEqual,
VersionedVariable left,
VersionedVariable right)
{
// TODO: Store the comparison result to the interpretation stack when expected in ViewModel
// Only let the heap model know that we are interested in them
// so that it displays them later
this.heapModelRecorder.GetLocation(left);
this.heapModelRecorder.GetLocation(right);
}
private void AddVariableHeapLocation(VersionedVariable variable)
{
Contract.Requires(variable.Variable.IsReference);
var heapLocation = this.heapModelRecorder.GetLocation(variable);
if (this.areAssignmentsPostponedToNextNode)
{
this.nextNodeHeapLocations.Add(heapLocation);
}
else
{
this.currentNodeHeapLocations.Add(heapLocation);
}
}
private void AddVariableInterpretation(VersionedVariable variable)
{
Contract.Requires(!variable.Variable.IsReference);
var symbolName = this.smtContextHandler.GetVariableVersionSymbol(
variable.Variable,
variable.Version);
var interpretation = this.smtModel.GetInterpretation(symbolName);
if (this.areAssignmentsPostponedToNextNode)
{
this.nextNodeInterpretations.Add(interpretation);
}
else
{
this.currentNodeInterpretations.Add(interpretation);
}
}
protected override void OnAfterPathStepRetracted(FlowEdge edge)
{
// Identify the creation of new objects on the heap
if (edge is OuterFlowEdge outerEdge &&
outerEdge.Kind == OuterFlowEdgeKind.MethodCall &&
outerEdge.From is CallFlowNode callNode &&
callNode.IsObjectCreation)
{
// "this" must be the first variable in the constructor by convention
var thisVar = edge.To.Graph.LocalVariables[0];
Contract.Assert(thisVar.IsReference);
var versionedVar = new VersionedVariable(thisVar, this.GetVariableVersion(thisVar));
this.heapModelRecorder.AllocateNew(versionedVar);
}
this.AddNodeValues();
}
protected override void OnFieldWriteRetracted(
VersionedVariable reference,
IFieldDefinition field,
Expression value)
{
if (value.Sort == References.Sort)
{
if (!(value is FlowVariable valVar))
{
throw new NotSupportedException("Only versioned flow variables supported as references");
}
this.heapModelRecorder.WriteReferenceField(reference, field, this.GetVersioned(valVar));
}
else
{
var valueInterpretation = this.smtModel.GetInterpretation(this.NameProvider, value);
this.heapModelRecorder.WriteValueField(reference, field, valueInterpretation);
}
this.AddVariableHeapLocation(reference);
}
protected override void OnVariableAssigned(
FlowVariable variable,
int lastVersion,
Expression value)
{
if (variable.IsReference)
{
var leftRef = new VersionedVariable(variable, lastVersion);
var rightRef = this.GetVersioned((FlowVariable)value);
this.Heap.AssignReference(leftRef, rightRef);
}
else if (References.IsReferenceComparison(value, out bool areEqual, out var left, out var right))
{
var varLeft = this.GetVersioned(left);
var varRight = this.GetVersioned(right);
value = this.Heap.GetEqualityExpression(areEqual, varLeft, varRight);
}
if (!variable.IsReference)
{
this.AssertEquals(variable, lastVersion, value);
}
}
public NamedVariable GetNamedVariable(VersionedVariable variable)
{
var name = this.owner.contextHandler.GetVariableVersionSymbol(variable.Variable, variable.Version);
return(ExpressionFactory.NamedVariable(variable.Variable.Sort, name));
}