/// <summary>
/// Visits the state transition graph to find and return
/// the node for the given summary.
/// </summary>
/// <param name="summary">MethodSummary</param>
/// <param name="visited">Already visited nodes</param>
/// <returns>StateTransitionGraphNode</returns>
private StateTransitionGraphNode GetGraphNodeForSummary(MethodSummary summary,
HashSet <StateTransitionGraphNode> visited)
{
visited.Add(this);
StateTransitionGraphNode stateNode = null;
if ((this.OnEntry != null && this.OnEntry.Equals(summary)) ||
(this.OnExit != null && this.OnExit.Equals(summary)) ||
this.Actions.Any(v => v.Equals(summary)))
{
stateNode = this;
}
else
{
foreach (var successor in this.ISuccessors.Where(v => !visited.Contains(v)))
{
var node = successor.GetGraphNodeForSummary(summary, visited);
if (node != null)
{
stateNode = node;
break;
}
}
}
return(stateNode);
}
/// <summary>
/// Constructs the node using information from the given state transitions
/// and action bindings.
/// </summary>
/// <param name="stateTransitions">State transitions</param>
/// <param name="actionBindings">Action bindings</param>
/// <param name="visited">Already visited nodes</param>
private void Construct(Dictionary <ClassDeclarationSyntax, HashSet <ClassDeclarationSyntax> > stateTransitions,
Dictionary <ClassDeclarationSyntax, HashSet <MethodDeclarationSyntax> > actionBindings,
HashSet <StateTransitionGraphNode> visited)
{
visited.Add(this);
foreach (var method in this.State.ChildNodes().OfType <MethodDeclarationSyntax>())
{
var summary = MethodSummary.Factory.Summarize(method);
if (method.Modifiers.Any(SyntaxKind.OverrideKeyword) &&
method.Identifier.ValueText.Equals("OnEntry"))
{
this.OnEntry = summary;
}
else if (method.Modifiers.Any(SyntaxKind.OverrideKeyword) &&
method.Identifier.ValueText.Equals("OnExit"))
{
this.OnExit = summary;
}
}
var actions = new HashSet <MethodDeclarationSyntax>();
if (actionBindings.ContainsKey(this.State))
{
actions = actionBindings[this.State];
}
foreach (var action in actions)
{
var actionSummary = MethodSummary.Factory.Summarize(action);
this.Actions.Add(actionSummary);
}
var transitions = new HashSet <ClassDeclarationSyntax>();
if (stateTransitions.ContainsKey(this.State))
{
transitions = stateTransitions[this.State];
}
foreach (var successorState in transitions)
{
var successor = visited.FirstOrDefault(v => v.State.Equals(successorState));
if (successor != null)
{
this.ISuccessors.Add(successor);
successor.IPredecessors.Add(this);
}
else
{
successor = new StateTransitionGraphNode(successorState, this.Machine);
this.ISuccessors.Add(successor);
successor.IPredecessors.Add(this);
successor.Construct(stateTransitions, actionBindings, visited);
}
}
}
/// <summary>
/// Query checking if the field is accessed before being reset
/// in the given state transition node.
/// </summary>
/// <param name="node">StateTransitionGraphNode</param>
/// <param name="input">Input</param>
/// <param name="isFirstVisit">True if first node to visit</param>
/// <returns>Boolean value</returns>
private static bool IsAccessedBeforeBeingReset(StateTransitionGraphNode node,
object input, bool isFirstVisit)
{
var summary = ((Tuple <MethodSummary, ISymbol>)input).Item1;
var fieldSymbol = ((Tuple <MethodSummary, ISymbol>)input).Item2;
var result = false;
if (isFirstVisit && node.OnExit != null && !summary.Equals(node.OnExit))
{
foreach (var action in node.Actions)
{
result = action.FieldAccessSet.ContainsKey(fieldSymbol as IFieldSymbol);
if (result)
{
break;
}
}
if (!result && node.OnExit != null)
{
result = node.OnExit.FieldAccessSet.ContainsKey(fieldSymbol as IFieldSymbol);
}
}
else if (!isFirstVisit)
{
if (node.OnEntry != null)
{
result = node.OnEntry.FieldAccessSet.ContainsKey(fieldSymbol as IFieldSymbol);
}
if (!result)
{
foreach (var action in node.Actions)
{
result = action.FieldAccessSet.ContainsKey(fieldSymbol as IFieldSymbol);
if (result)
{
break;
}
}
}
if (!result && node.OnExit != null)
{
result = node.OnExit.FieldAccessSet.ContainsKey(fieldSymbol as IFieldSymbol);
}
}
return(result);
}
/// <summary>
/// Query checking if the field is accessed before being reset
/// in the given state transition node.
/// </summary>
/// <param name="node">StateTransitionGraphNode</param>
/// <param name="input">Input</param>
/// <param name="isFirstVisit">True if first node to visit</param>
/// <returns>Boolean value</returns>
private static bool IsAccessedBeforeBeingReset(StateTransitionGraphNode node,
object input, bool isFirstVisit)
{
var summary = ((Tuple<MethodSummary, ISymbol>)input).Item1;
var fieldSymbol = ((Tuple<MethodSummary, ISymbol>)input).Item2;
var result = false;
if (isFirstVisit && node.OnExit != null && !summary.Equals(node.OnExit))
{
foreach (var action in node.Actions)
{
result = action.FieldAccessSet.ContainsKey(fieldSymbol as IFieldSymbol);
if (result)
{
break;
}
}
if (!result && node.OnExit != null)
{
result = node.OnExit.FieldAccessSet.ContainsKey(fieldSymbol as IFieldSymbol);
}
}
else if (!isFirstVisit)
{
if (node.OnEntry != null)
{
result = node.OnEntry.FieldAccessSet.ContainsKey(fieldSymbol as IFieldSymbol);
}
if (!result)
{
foreach (var action in node.Actions)
{
result = action.FieldAccessSet.ContainsKey(fieldSymbol as IFieldSymbol);
if (result)
{
break;
}
}
}
if (!result && node.OnExit != null)
{
result = node.OnExit.FieldAccessSet.ContainsKey(fieldSymbol as IFieldSymbol);
}
}
return result;
}
/// <summary>
/// Tries to construct the state transition graph for the given machine.
/// </summary>
/// <param name="machine">Machine</param>
private static void ConstructGraphForMachine(ClassDeclarationSyntax machine)
{
var model = AnalysisContext.Compilation.GetSemanticModel(machine.SyntaxTree);
Dictionary <ClassDeclarationSyntax, HashSet <ClassDeclarationSyntax> > stateTransitions = null;
StateTransitionAnalysis.TryParseStateTransitions(out stateTransitions, machine, model);
Dictionary <ClassDeclarationSyntax, HashSet <MethodDeclarationSyntax> > actionBindings = null;
StateTransitionAnalysis.TryParseActionBindings(out actionBindings, machine, model);
StateTransitionAnalysis.ComputeStatistics(stateTransitions, actionBindings);
ClassDeclarationSyntax initState = null;
foreach (var state in stateTransitions)
{
foreach (var attributeList in state.Key.AttributeLists)
{
foreach (var attribute in attributeList.Attributes)
{
if (attribute.Name.ToString().Equals("Microsoft.PSharp.Start"))
{
initState = state.Key;
}
}
}
}
if (initState == null)
{
return;
}
var initNode = new StateTransitionGraphNode(initState, machine);
initNode.IsStartNode = true;
initNode.Construct(stateTransitions, actionBindings);
AnalysisContext.StateTransitionGraphs.Add(machine, initNode);
}
/// <summary>
/// Returns true if the given field symbol is being accessed
/// before being reset.
/// </summary>
/// <param name="field">Field</param>
/// <param name="summary">MethodSummary</param>
/// <returns>Boolean value</returns>
internal static bool IsAccessedBeforeBeingReset(ISymbol field, MethodSummary summary)
{
StateTransitionGraphNode stateTransitionNode = null;
if (!AnalysisContext.StateTransitionGraphs.ContainsKey(summary.Machine))
{
return(true);
}
stateTransitionNode = AnalysisContext.StateTransitionGraphs[summary.Machine].
GetGraphNodeForSummary(summary);
if (stateTransitionNode == null)
{
return(true);
}
var result = stateTransitionNode.VisitSelfAndSuccessors(IsAccessedBeforeBeingReset,
new Tuple <MethodSummary, ISymbol>(summary, field));
return(false);
}
/// <summary>
/// Tries to construct the state transition graph for the given machine.
/// </summary>
/// <param name="machine">Machine</param>
private void ConstructGraphForMachine(ClassDeclarationSyntax machine)
{
var model = AnalysisContext.Compilation.GetSemanticModel(machine.SyntaxTree);
Dictionary<ClassDeclarationSyntax, HashSet<ClassDeclarationSyntax>> stateTransitions = null;
this.TryParseStateTransitions(out stateTransitions, machine, model);
Dictionary<ClassDeclarationSyntax, HashSet<MethodDeclarationSyntax>> actionBindings = null;
this.TryParseActionBindings(out actionBindings, machine, model);
this.ComputeStatistics(stateTransitions, actionBindings);
ClassDeclarationSyntax initState = null;
foreach (var state in stateTransitions)
{
foreach (var attributeList in state.Key.AttributeLists)
{
foreach (var attribute in attributeList.Attributes)
{
if (attribute.Name.ToString().Equals("Microsoft.PSharp.Start"))
{
initState = state.Key;
}
}
}
}
if (initState == null)
{
return;
}
var initNode = new StateTransitionGraphNode(this.AnalysisContext, initState, machine);
initNode.IsStartNode = true;
initNode.Construct(stateTransitions, actionBindings);
AnalysisContext.StateTransitionGraphs.Add(machine, initNode);
}
/// <summary>
/// Constructs the node using information from the given state transitions
/// and action bindings.
/// </summary>
/// <param name="stateTransitions">State transitions</param>
/// <param name="actionBindings">Action bindings</param>
/// <param name="visited">Already visited nodes</param>
private void Construct(Dictionary<ClassDeclarationSyntax, HashSet<ClassDeclarationSyntax>> stateTransitions,
Dictionary<ClassDeclarationSyntax, HashSet<MethodDeclarationSyntax>> actionBindings,
HashSet<StateTransitionGraphNode> visited)
{
visited.Add(this);
foreach (var method in this.State.ChildNodes().OfType<MethodDeclarationSyntax>())
{
var summary = MethodSummary.Factory.Summarize(this.AnalysisContext, method);
if (method.Modifiers.Any(SyntaxKind.OverrideKeyword) &&
method.Identifier.ValueText.Equals("OnEntry"))
{
this.OnEntry = summary;
}
else if (method.Modifiers.Any(SyntaxKind.OverrideKeyword) &&
method.Identifier.ValueText.Equals("OnExit"))
{
this.OnExit = summary;
}
}
var actions = new HashSet<MethodDeclarationSyntax>();
if (actionBindings.ContainsKey(this.State))
{
actions = actionBindings[this.State];
}
foreach (var action in actions)
{
var actionSummary = MethodSummary.Factory.Summarize(this.AnalysisContext, action);
this.Actions.Add(actionSummary);
}
var transitions = new HashSet<ClassDeclarationSyntax>();
if (stateTransitions.ContainsKey(this.State))
{
transitions = stateTransitions[this.State];
}
foreach (var successorState in transitions)
{
var successor = visited.FirstOrDefault(v => v.State.Equals(successorState));
if (successor != null)
{
this.ISuccessors.Add(successor);
successor.IPredecessors.Add(this);
}
else
{
successor = new StateTransitionGraphNode(this.AnalysisContext, successorState, this.Machine);
this.ISuccessors.Add(successor);
successor.IPredecessors.Add(this);
successor.Construct(stateTransitions, actionBindings, visited);
}
}
}
