/// <summary>
/// Model check an expression to find inputs that lead to it being false.
/// </summary>
/// <param name="expression">The expression.</param>
/// <returns>
/// Assignment to zen arbitrary variables that make the expression false.
/// Null if no such assignment exists.
/// </returns>
public Dictionary <object, object> ModelCheck(Zen <bool> expression)
{
var symbolicEvaluator = new SymbolicEvaluationVisitor <TModel, TVar, TBool, TInt>(solver);
var env = new SymbolicEvaluationEnvironment <TModel, TVar, TBool, TInt>();
var symbolicResult =
(SymbolicBool <TModel, TVar, TBool, TInt>)expression.Accept(symbolicEvaluator, env);
// Console.WriteLine($"[time] model checking: {watch.ElapsedMilliseconds}ms");
// watch.Restart();
var possibleModel = solver.Satisfiable(symbolicResult.Value);
// Console.WriteLine($"[time] get sat: {watch.ElapsedMilliseconds}ms");
if (!possibleModel.HasValue)
{
return(null);
}
var model = possibleModel.Value;
// compute the input given the assignment
var arbitraryAssignment = new Dictionary <object, object>();
foreach (var kv in symbolicEvaluator.ArbitraryVariables)
{
var expr = kv.Key;
var variable = kv.Value;
arbitraryAssignment.Add(expr, this.solver.Get(model, variable));
}
return(arbitraryAssignment);
}
private static T Interpret <T>(Zen <T> expression, ImmutableDictionary <string, object> arguments)
{
var environment = new ExpressionEvaluatorEnvironment(arguments);
var interpreter = new ExpressionEvaluator();
return((T)expression.Accept(interpreter, environment));
}
internal static Expression CompileToBlock <T>(
Zen <T> zenExpression,
ExpressionConverterEnvironment env,
ImmutableDictionary <object, Expression> subexpressionCache,
int currentMatchUnrollingDepth,
int maxMatchUnrollingDepth)
{
var converter = new ExpressionConverter(subexpressionCache, currentMatchUnrollingDepth, maxMatchUnrollingDepth);
var expr = zenExpression.Accept(converter, env);
converter.BlockExpressions.Add(expr);
return(Expression.Block(converter.Variables, converter.BlockExpressions.ToArray()));
}
/// <summary>
/// Model check an expression to find inputs that lead to it being false.
/// </summary>
/// <param name="expression">The expression.</param>
/// <returns>
/// Assignment to zen arbitrary variables that make the expression false.
/// Null if no such assignment exists.
/// </returns>
public Dictionary <object, object> ModelCheck(Zen <bool> expression)
{
var symbolicEvaluator = new SymbolicEvaluationVisitor <TModel, TVar, TBool, TBitvec, TInt, TString>(solver);
var env = new SymbolicEvaluationEnvironment <TModel, TVar, TBool, TBitvec, TInt, TString>();
var symbolicResult =
(SymbolicBool <TModel, TVar, TBool, TBitvec, TInt, TString>)expression.Accept(symbolicEvaluator, env);
var possibleModel = solver.Satisfiable(symbolicResult.Value);
if (!possibleModel.HasValue)
{
return(null);
}
var model = possibleModel.Value;
// compute the input given the assignment
var arbitraryAssignment = new Dictionary <object, object>();
foreach (var kv in symbolicEvaluator.ArbitraryVariables)
{
var expr = kv.Key;
var variable = kv.Value;
var type = expr.GetType().GetGenericArguments()[0];
var obj = this.solver.Get(model, variable);
if (ReflectionUtilities.IsFixedIntegerType(type))
{
obj = type.GetConstructor(new Type[] { typeof(byte[]) }).Invoke(new object[] { obj });
}
arbitraryAssignment.Add(expr, obj);
}
return(arbitraryAssignment);
}
public Dictionary <object, ImmutableHashSet <object> > Compute <T>(Zen <T> expr)
{
var _ = expr.Accept(this, new Unit());
return(this.DisjointSets);
}
