private static void AnalyzeMethod(SyntaxNodeAnalysisContext context)
 {
     Contract.Requires(!false);
     try
     {
         using (Context ctx = new Context())
         {
             var method = new Method(context.Node, context, ctx);
             Solve(method);
         }
     }
     catch (Exception ex)
     {
         context.ReportDiagnostic(Diagnostic.Create
                                  (
                                      DiagnosticDefinition.Get("RA0003"),
                                      context.Node.GetLocation(),
                                      ex
                                  ));
     }
 }
        private static void Solve(Method context)
        {
            var      solver = context.Z3.MkSimpleSolver();
            BoolExpr requireCondition;

            if (context.Requires.Take(2).Count() == 2)
            {
                requireCondition = context.Z3.MkAnd(context.Requires);
            }
            else if (context.Requires.Any())
            {
                requireCondition = context.Requires.First();
            }
            else
            {
                // no requires
                return;
            }
            requireCondition = requireCondition.Simplify() as BoolExpr;
            solver.Add(requireCondition);
            var status = solver.Check();

            if (status == Status.SATISFIABLE)
            {
                StringBuilder sb = new StringBuilder();
                foreach (var condition in context.Parameters.SelectMany(p => p.AllNamedExpressions))
                {
                    var val = solver.Model.Eval(condition.Value);
                    sb.Append(condition.Key);
                    sb.Append(" => ");
                    sb.AppendLine(val.ToString());
                }

                foreach (var location in context.RequireConditions.Select(c => c.GetLocation()))
                {
                    context.NodeAnalysisContext.ReportDiagnostic(Diagnostic.Create
                                                                 (
                                                                     DiagnosticDefinition.Get("RA0000"),
                                                                     location,
                                                                     sb.ToString()
                                                                 ));
                }
                return;
            }
            if (status == Status.UNSATISFIABLE)
            {
                StringBuilder sb = new StringBuilder();
                foreach (BoolExpr c in solver.UnsatCore)
                {
                    sb.AppendFormat("{0}", c);
                    sb.AppendLine();
                }
                foreach (var location in context.RequireConditions.Select(c => c.GetLocation()))
                {
                    context.NodeAnalysisContext.ReportDiagnostic(Diagnostic.Create
                                                                 (
                                                                     DiagnosticDefinition.Get("RA0001"),
                                                                     location,
                                                                     requireCondition
                                                                 ));
                }
                return;
            }
            if (status == Status.UNKNOWN)
            {
                foreach (var location in context.RequireConditions.Select(c => c.GetLocation()))
                {
                    context.NodeAnalysisContext.ReportDiagnostic(Diagnostic.Create
                                                                 (
                                                                     DiagnosticDefinition.Get("RA0002"),
                                                                     location,
                                                                     requireCondition
                                                                 ));
                }
                return;
            }
        }