public void MergeMultipleDisjointVariables()
{
var sources = new[]
{
CreateDummyNode(0),
CreateDummyNode(1),
};
var variables = new[]
{
new DummyVariable("V_1"),
new DummyVariable("V_2"),
};
var variables1 = ImmutableDictionary <IVariable, SymbolicValue <DummyInstruction> > .Empty;
variables1 = variables1.SetItem(variables[0], SymbolicValue <DummyInstruction> .CreateVariableValue(sources[0], variables[0]));
var variables2 = ImmutableDictionary <IVariable, SymbolicValue <DummyInstruction> > .Empty;
variables2 = variables2.SetItem(variables[1], SymbolicValue <DummyInstruction> .CreateVariableValue(sources[1], variables[1]));
var state1 = new SymbolicProgramState <DummyInstruction>(0, variables1);
var state2 = new SymbolicProgramState <DummyInstruction>(0, variables2);
Assert.True(state1.MergeStates(state2, out var newState));
Assert.Equal(new HashSet <DataFlowNode <DummyInstruction> >(new [] { sources[0] }), newState.Variables[variables[0]].GetNodes());
Assert.Equal(new HashSet <DataFlowNode <DummyInstruction> >(new [] { sources[1] }), newState.Variables[variables[1]].GetNodes());
}
public void MergeMultipleSingleChangeShouldOnlyCreateNewInstancesForChangedSlots()
{
var nodes = new[]
{
CreateDummyNode(0),
CreateDummyNode(1),
CreateDummyNode(2),
CreateDummyNode(3),
};
var sources = new[]
{
new[]
{
nodes[0]
},
new[]
{
nodes[1]
},
new[]
{
nodes[2],
nodes[3],
}
};
var values1 = new[]
{
SymbolicValue <DummyInstruction> .CreateStackValue(sources[0][0]),
SymbolicValue <DummyInstruction> .CreateStackValue(sources[1][0]),
SymbolicValue <DummyInstruction> .CreateStackValue(sources[2][0]),
};
var stack1 = ImmutableStack.Create(values1);
var values2 = new[]
{
SymbolicValue <DummyInstruction> .CreateStackValue(sources[0][0]),
SymbolicValue <DummyInstruction> .CreateStackValue(sources[1][0]),
SymbolicValue <DummyInstruction> .CreateStackValue(sources[2][1]),
};
var stack2 = ImmutableStack.Create(values2);
var state1 = new SymbolicProgramState <DummyInstruction>(0, stack1);
var state2 = new SymbolicProgramState <DummyInstruction>(0, stack2);
Assert.True(state1.MergeStates(state2, out var newState));
Assert.NotSame(state1.Stack.Peek(), newState.Stack.Peek());
Assert.Same(state1.Stack.ElementAt(1), newState.Stack.ElementAt(1));
Assert.Same(state1.Stack.ElementAt(2), newState.Stack.ElementAt(2));
}
public void MergeMultiple()
{
var sources = new[]
{
new[]
{
CreateDummyNode(0),
CreateDummyNode(1)
},
new[]
{
CreateDummyNode(2),
CreateDummyNode(3),
},
new[]
{
CreateDummyNode(4),
CreateDummyNode(5),
}
};
var values1 = new[]
{
SymbolicValue <DummyInstruction> .CreateStackValue(sources[0][0]),
SymbolicValue <DummyInstruction> .CreateStackValue(sources[1][0]),
SymbolicValue <DummyInstruction> .CreateStackValue(sources[2][0]),
};
var stack1 = ImmutableStack.Create(values1);
var values2 = new[]
{
SymbolicValue <DummyInstruction> .CreateStackValue(sources[0][1]),
SymbolicValue <DummyInstruction> .CreateStackValue(sources[1][1]),
SymbolicValue <DummyInstruction> .CreateStackValue(sources[2][1]),
};
var stack2 = ImmutableStack.Create(values2);
var state1 = new SymbolicProgramState <DummyInstruction>(0, stack1);
var state2 = new SymbolicProgramState <DummyInstruction>(0, stack2);
Assert.True(state1.MergeStates(state2, out var newState));
int index = sources.Length - 1;
foreach (var slot in newState.Stack)
{
Assert.Equal(new HashSet <DataFlowNode <DummyInstruction> >(sources[index]), slot.GetNodes());
index--;
}
}
public void MergeStackImbalance()
{
var stack1 = ImmutableStack.Create(
new SymbolicValue <DummyInstruction>(),
new SymbolicValue <DummyInstruction>()
);
var stack2 = ImmutableStack.Create(new SymbolicValue <DummyInstruction>());
var state1 = new SymbolicProgramState <DummyInstruction>(0, stack1);
var state2 = new SymbolicProgramState <DummyInstruction>(0, stack2);
Assert.Throws <StackImbalanceException>(() => state1.MergeStates(state2, out _));
}
public void MergeSingleNoChange()
{
var source = CreateDummyNode(0);
var value1 = SymbolicValue <DummyInstruction> .CreateStackValue(source);
var stack1 = ImmutableStack.Create(value1);
var value2 = SymbolicValue <DummyInstruction> .CreateStackValue(source);
var stack2 = ImmutableStack.Create(value2);
var state1 = new SymbolicProgramState <DummyInstruction>(0, stack1);
var state2 = new SymbolicProgramState <DummyInstruction>(0, stack2);
Assert.False(state1.MergeStates(state2, out var newState));
Assert.Equal(new HashSet <DataFlowNode <DummyInstruction> >(new[] { source }), newState.Stack.Peek().GetNodes());
}
public void MergeSingleVariableNoChange()
{
var source = CreateDummyNode(0);
var variable = new DummyVariable("V_1");
var variables1 = ImmutableDictionary <IVariable, SymbolicValue <DummyInstruction> > .Empty;
variables1 = variables1.SetItem(variable, SymbolicValue <DummyInstruction> .CreateVariableValue(source, variable));
var variables2 = ImmutableDictionary <IVariable, SymbolicValue <DummyInstruction> > .Empty;
variables2 = variables2.SetItem(variable, SymbolicValue <DummyInstruction> .CreateVariableValue(source, variable));
var state1 = new SymbolicProgramState <DummyInstruction>(0, variables1);
var state2 = new SymbolicProgramState <DummyInstruction>(0, variables2);
Assert.False(state1.MergeStates(state2, out var newState));
Assert.Equal(new HashSet <DataFlowNode <DummyInstruction> >(new [] { source }), newState.Variables[variable].GetNodes());
}
public void MergeSingle()
{
var sources = new[]
{
CreateDummyNode(0), CreateDummyNode(1),
};
var value1 = SymbolicValue <DummyInstruction> .CreateStackValue(sources[0]);
var stack1 = ImmutableStack.Create(value1);
var value2 = SymbolicValue <DummyInstruction> .CreateStackValue(sources[1]);
var stack2 = ImmutableStack.Create(value2);
var state1 = new SymbolicProgramState <DummyInstruction>(0, stack1);
var state2 = new SymbolicProgramState <DummyInstruction>(0, stack2);
Assert.True(state1.MergeStates(state2, out var newState));
Assert.Equal(new HashSet <DataFlowNode <DummyInstruction> >(sources), newState.Stack.Peek().GetNodes());
}
private static bool ApplyStateChange(
GraphBuilderContext context,
ref SymbolicProgramState <TInstruction> currentState)
{
bool changed;
if (context.RecordedStates.TryGetValue(currentState.ProgramCounter, out var recordedState))
{
// We are revisiting this address, merge program states.
changed = recordedState.MergeStates(currentState, out currentState);
if (changed)
{
context.RecordedStates[currentState.ProgramCounter] = currentState;
}
}
else
{
// This is a new unvisited address.
context.RecordedStates.Add(currentState.ProgramCounter, currentState);
changed = true;
}
return(changed);
}
/// <inheritdoc />
public override int GetTransitionCount(SymbolicProgramState <Instruction> currentState,
in Instruction instruction)
/// <summary>
/// Creates a new program state transition.
/// </summary>
/// <param name="nextState">The new program state.</param>
/// <param name="edgeType">The type of edge that was taken.</param>
public StateTransition(SymbolicProgramState <TInstruction> nextState, ControlFlowEdgeType edgeType)
{
NextState = nextState;
EdgeType = edgeType;
}
/// <summary>
/// Creates a new program state transition.
/// </summary>
/// <param name="nextState">The new program state.</param>
/// <param name="edgeType">The type of edge that was taken.</param>
public StateTransition(SymbolicProgramState <TInstruction> nextState, ControlFlowEdgeType edgeType)
{
NextState = nextState ?? throw new ArgumentNullException(nameof(nextState));
EdgeType = edgeType;
}
/// <inheritdoc />
public abstract int GetTransitionCount(SymbolicProgramState <TInstruction> currentState,
in TInstruction instruction);
private void ResolveAndScheduleSuccessors(
GraphBuilderContext context,
SymbolicProgramState <TInstruction> currentState,
in TInstruction instruction,
