Exemple #1
0
        /// <summary>
        ///  Project the parameters of the calling method/function
        /// </summary>
        /// <param name="expression"></param>
        /// <param name="proofState"></param>
        /// <returns></returns>
        public override Expression Generate(Expression expression, ProofState proofState)
        {
            var vars = proofState.GetAllDafnyVars().Values.ToList().Where(IsParam);
            var ret  = new List <Expression>();

            foreach (var x in vars)
            {
                ret.Add(new TacticLiteralExpr(x.Variable.Name));
            }
            return(GenerateEAtomExprAsSeq(ret));
        }
Exemple #2
0
        public override IEnumerable <object> Generate(Expression expression, ProofState proofState)
        {
            var vars = proofState.GetAllDafnyVars().Values.ToList();

            yield return(vars.Select(x => x.Variable).ToList());
        }
Exemple #3
0
 /// <summary>
 ///  Project the parameters of the calling method/function
 /// </summary>
 /// <param name="expression"></param>
 /// <param name="proofState"></param>
 /// <returns></returns>
 public override IEnumerable<object> Generate(Expression expression, ProofState proofState) {
   var vars = proofState.GetAllDafnyVars().Values.ToList().Where(IsParam);
   yield return vars.Select(x => x.Variable).ToList();
 }
Exemple #4
0
        public override IEnumerable <ProofState> Generate(Statement statement, ProofState state)
        {
            List <List <IVariable> > args  = new List <List <IVariable> >();
            List <IVariable>         mdIns = new List <IVariable>();
            List <Expression>        callArguments;
            bool branchGenerated = false;

            state.NeedVerify = true;

            InitArgs(state, statement, out callArguments);

            /**********************
            * init lemmas
            **********************/
            //check the number of arguments
            if (callArguments == null || callArguments.Count != 2)
            {
                state.ReportTacticError(statement.Tok, " The number of arguments for explore is not correct, expect 2.");
                yield break;
            }
            // get the first arg: a sequence of lemmas
            var members0 = EvalExpr.EvalTacticExpression(state, callArguments[0]) as SeqDisplayExpr;

            if (members0 == null)
            {
                state.ReportTacticError(statement.Tok, Printer.ExprToString(callArguments[0]) + " is not a sequence.");
                yield break;
            }
            List <MemberDecl> members = new List <MemberDecl>();

            foreach (var mem in members0.Elements)
            {
                if (!(mem is TacticLiteralExpr))
                {
                    state.ReportTacticError(statement.Tok,
                                            "In " + Printer.ExprToString(callArguments[0]) +
                                            Printer.ExprToString(mem) + " is not a lemma.");
                    yield break;
                }
                var key = (string)(mem as TacticLiteralExpr).Value;
                if (state.Members.ContainsKey(key))
                {
                    members.Add(state.Members[key]);
                }
                else
                {
                    state.ReportTacticError(statement.Tok,
                                            "In " + Printer.ExprToString(callArguments[0]) + ", " +
                                            key + " is not a lemma.");
                    yield break;
                }
            }
            if (members.Count == 0)
            {
                branchGenerated = true;
                yield return(state);

                yield break;
            }

            foreach (var member in members)
            {
                mdIns.Clear();
                args.Clear();

                var md = (MemberDecl)member;

                // take the membed decl parameters
                var method = md as Method;
                if (method != null)
                {
                    mdIns.AddRange(method.Ins);
                }
                else if (md is Function)
                {
                    mdIns.AddRange(((Function)md).Formals);
                }
                else
                {
                    state.ReportTacticError(statement.Tok,
                                            Printer.ExprToString(callArguments[0]) + " is neither a Method or a Function");
                    yield break;
                }

                /**********************
                * init args for lemmas
                **********************/
                var ovars = EvalExpr.EvalTacticExpression(state, callArguments[1]) as SeqDisplayExpr;
                if (ovars == null)
                {
                    state.ReportTacticError(statement.Tok, Printer.ExprToString(callArguments[1]) + " is not a sequence.");
                    yield break;
                }

                List <IVariable> vars = new List <IVariable>();

                foreach (var var in ovars.Elements)
                {
                    string key;
                    if (var is TacticLiteralExpr)
                    {
                        key = (string)(var as TacticLiteralExpr).Value;
                    }
                    else if (var is NameSegment)
                    {
                        key = (var as NameSegment).Name;
                    }
                    else
                    {
                        state.ReportTacticError(statement.Tok,
                                                "In " + Printer.ExprToString(callArguments[1]) + ", " +
                                                Printer.ExprToString(var) + " is not a dafny variable.");
                        yield break;
                    }

                    if (state.GetAllDafnyVars().ContainsKey(key))
                    {
                        vars.Add(state.GetAllDafnyVars()[key].Variable);
                    }
                    else
                    {
                        state.ReportTacticError(statement.Tok,
                                                "In " + Printer.ExprToString(callArguments[1]) + ", " +
                                                key + " is not in scope.");
                        yield break;
                    }
                }

                //for the case of no args, just add an empty list
                if (mdIns.Count == 0)
                {
                    args.Add(new List <IVariable>());
                }
                //if any of the arguements is not valid, set it to false.
                bool flag = true;
                for (int i = 0; i < mdIns.Count; i++)
                {
                    var item = mdIns[i];
                    args.Add(new List <IVariable>());
                    foreach (var arg in vars)
                    {
                        // get variable type
                        Type type = state.GetDafnyVarType(arg.Name);
                        if (type != null)
                        {
                            if (type is UserDefinedType && item.Type is UserDefinedType)
                            {
                                var udt1 = type as UserDefinedType;
                                var udt2 = (UserDefinedType)item.Type;
                                if (udt1.Name == udt2.Name)
                                {
                                    args[i].Add(arg);
                                }
                            }
                            else
                            {
                                // if variable type and current argument types match, or the type is yet to be inferred
                                if (item.Type.ToString() == type.ToString() || type is InferredTypeProxy)
                                {
                                    args[i].Add(arg);
                                }
                            }
                        }
                        else
                        {
                            args[i].Add(arg);
                        }
                    }

                    /**
                     * if no type correct variables have been added we can return
                     * because we won't be able to generate valid calls
                     */
                    if (args[i].Count == 0)
                    {
                        flag = false;
                    }
                }
                // permute lemma call for the current lemma
                if (flag)
                {
                    foreach (var result in PermuteArguments(args, 0, new List <NameSegment>()))
                    {
                        // create new fresh list of items to remove multiple references to the same object
                        List <Expression> newList = result.Cast <Expression>().ToList().Copy();
                        ApplySuffix       aps     = new ApplySuffix(callArguments[0].tok,
                                                                    new NameSegment(callArguments[0].tok, md.Name, null),
                                                                    newList);

                        var        newState = state.Copy();
                        UpdateStmt us       = new UpdateStmt(aps.tok, aps.tok, new List <Expression>(),
                                                             new List <AssignmentRhs> {
                            new ExprRhs(aps)
                        });
                        newState.AddStatement(us);
                        branchGenerated = true;
                        yield return(newState);
                    }
                }
            }
            // for the case when no lemma call is generated.
            if (!branchGenerated)
            {
                yield return(state);
            }
        }
Exemple #5
0
        public override IEnumerable <ProofState> EvalInit(Statement statement, ProofState state)
        {
            Contract.Assume(statement != null);
            Contract.Assume(statement is TacticForallStmt);

            _stmt = statement as TacticForallStmt;

            Contract.Assert(_stmt != null);

            // do basic simplification
            // maybe do a check and throw an error instead?
            // fixme: error returns null!
            //var e = (ForallExpr) SimpTacticExpr.SimpTacExpr(state0, _stmt.Spec);
            var e = (ForallExpr)SimpExpr.SimpTacticExpr(state, _stmt.Spec);

            // var e = _stmt.Spec as ForallExpr;
            // to rename expressions
            RenameVar rn = new RenameVar();
            // to rename in the body of statement
            RenameVar     rnBody   = new RenameVar();
            List <String> usedVars = state.GetAllDafnyVars().Keys.ToList();

            usedVars.AddRange(state.GetAllTVars().Keys.ToList());

            //List<String> tmp = new List<string>();
            AllVars.DeclaredVars(_stmt.Body.Body[0], ref usedVars);



            if (_stmt.Attributes != null && _stmt.Attributes.Name.Equals("vars"))
            {
                var attrs = _stmt.Attributes.Args;
                for (int i = 0; i < attrs.Count; i++)
                {
                    // todo: should really report an errors if first condition does not hold
                    var segment = attrs[i] as NameSegment;
                    if (segment != null && i < e.BoundVars.Count)
                    {
                        NameSegment ns = segment;
                        String      fv;
                        if (GenFreeVar(ns.Name, usedVars, out fv))
                        {
                            rnBody.AddRename(ns.Name, fv);
                        }
                        rn.AddRename(e.BoundVars[i].Name, fv);
                    } // else we should have an error
                    _vars = new List <BoundVar>();
                    foreach (BoundVar bv in e.BoundVars)
                    {
                        _vars.Add(rn.CloneBoundVar(bv));
                    }
                }
            }
            else
            {
                _vars = e.BoundVars;
            }

            foreach (var tmp in _vars)
            {
                state.AddDafnyVar(tmp.Name, new ProofState.VariableData {
                    Variable = tmp, Type = tmp.Type
                });
            }


            // we could even break  _ens into a set of all conjunctions?
            // what about forall x (forall y) x
            var expr = e.Term as BinaryExpr;

            if (expr != null && (expr.Op.Equals(BinaryExpr.Opcode.Imp)))
            {
                var be = expr;
                _range = rn.CloneExpr(be.E0);
                var t = new MaybeFreeExpression(rn.CloneExpr(be.E1));
                var l = new List <MaybeFreeExpression> {
                    t
                };
                _ens = l;
            }
            else
            {
                _range = new LiteralExpr(_stmt.Tok, true);
                var t = new MaybeFreeExpression(rn.CloneExpr(e.Term));
                var l = new List <MaybeFreeExpression> {
                    t
                };
                _ens = l;
            }

            // Note that we do not need to rename variables in the body (unless the variables in vars is changed)
            InitBasicFrameCtrl(new List <Statement>(), state.IsCurFramePartial(), null, VerifyN);

            state.AddNewFrame(this);

            var bodyFrame = new DefaultTacticFrameCtrl();

            var newBody = rnBody.CloneBlockStmt(_stmt.Body);

            bodyFrame.InitBasicFrameCtrl(newBody.Body, state.IsCurFramePartial(), null, VerifyN);
            bodyFrame.IsPartial = IsPartial;
            state.AddNewFrame(bodyFrame);

            yield return(state);
        }