Ejemplo n.º 1
0
 private Expr ElimPendingAsyncExpr(IdentifierExpr pa)
 {
     return(Expr.And(
                Expr.Or(elim.Keys.Select(a => ExprHelper.FunctionCall(a.pendingAsyncCtor.membership, pa))),
                Expr.Gt(Expr.Select(PAs, pa), Expr.Literal(0))
                ));
 }
Ejemplo n.º 2
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 private static Expr OutPermsSubsetInPerms(LinearDomain domain, IEnumerable<Expr> ins, IEnumerable<Expr> outs)
 {
   Expr inMultiset = ExprHelper.Old(PermissionMultiset(domain, ins));
   Expr outMultiset = PermissionMultiset(domain, outs);
   Expr subsetExpr = ExprHelper.FunctionCall(domain.mapLe, outMultiset, inMultiset);
   return Expr.Eq(subsetExpr, ExprHelper.FunctionCall(domain.mapConstBool, Expr.True));
 }
Ejemplo n.º 3
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 private Expr SubsetExpr(LinearDomain domain, Expr ie, Variable partition, int partitionCount)
 {
   Expr e = ExprHelper.FunctionCall(domain.mapConstInt, Expr.Literal(partitionCount));
   e = ExprHelper.FunctionCall(domain.mapEqInt, Expr.Ident(partition), e);
   e = ExprHelper.FunctionCall(domain.mapImp, ie, e);
   e = Expr.Eq(e, ExprHelper.FunctionCall(domain.mapConstBool, Expr.True));
   return e;
 }
Ejemplo n.º 4
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            private void ComputeWitnessedTransitionRelationExprs()
            {
                witnessedTransitionRelations = new List <Expr>();
                Dictionary <Variable, List <WitnessFunction> > varToWitnesses = FrameWithWitnesses.
                                                                                Where(x => NotEliminatedVars.Contains(frameIntermediateCopy[x])).
                                                                                ToDictionary(
                    x => frameIntermediateCopy[x],
                    x => transitionRelationComputer.globalVarToWitnesses[(GlobalVariable)x]);

                foreach (var witnessSet in varToWitnesses.Values.CartesianProduct())
                {
                    Dictionary <Variable, Expr> witnessSubst = new Dictionary <Variable, Expr>();
                    foreach (Tuple <Variable, WitnessFunction> pair in
                             Enumerable.Zip(varToWitnesses.Keys, witnessSet, Tuple.Create))
                    {
                        WitnessFunction witnessFunction = pair.Item2;
                        List <Expr>     args            = new List <Expr>();
                        foreach (var arg in witnessFunction.InputArgs)
                        {
                            Expr expr = null;
                            switch (arg.Kind)
                            {
                            case WitnessFunction.InputArgumentKind.FIRST_ARG:
                                // TODO: Add note on the reason of using second
                                expr = Expr.Ident(second.Params.
                                                  First(x => x.Name == second.Prefix + arg.Name));
                                break;

                            case WitnessFunction.InputArgumentKind.SECOND_ARG:
                                expr = Expr.Ident(first.Params.
                                                  First(x => x.Name == first.Prefix + arg.Name));
                                break;

                            case WitnessFunction.InputArgumentKind.PRE_STATE:
                                expr = ExprHelper.Old(Expr.Ident(
                                                          frame.First(x => x.Name == arg.Name)));
                                break;

                            case WitnessFunction.InputArgumentKind.POST_STATE:
                                expr = Expr.Ident(frame.First(x => x.Name == arg.Name));
                                break;

                            default:
                                Debug.Assert(false);
                                break;
                            }
                            args.Add(expr);
                        }
                        witnessSubst[pair.Item1] = ExprHelper.FunctionCall(
                            witnessFunction.function, args.ToArray()
                            );
                    }
                    var subst = Substituter.SubstitutionFromHashtable(witnessSubst);
                    witnessedTransitionRelations.Add(
                        Substituter.Apply(subst, TransitionRelationExpr));
                }
            }
Ejemplo n.º 5
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 public void AddTriggerAssumes(Program program)
 {
     foreach (Variable v in impl.LocVars)
     {
         var f = triggerFunctions[v];
         program.AddTopLevelDeclaration(f);
         var assume = CmdHelper.AssumeCmd(ExprHelper.FunctionCall(f, Expr.Ident(v)));
         impl.Blocks[0].Cmds.Insert(0, assume);
     }
 }
Ejemplo n.º 6
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        public Tuple <Procedure, Implementation> GenerateStepChecker(AtomicAction pendingAsync, Function pendingAsyncAdd)
        {
            this.checkName = "step";
            var requires = invariantAction.gate.Select(g => new Requires(false, g.Expr)).ToList();
            var ensures  = new List <Ensures> {
                GetEnsures(GetTransitionRelation(invariantAction))
            };
            var locals = new List <Variable>();

            if (!HasChoice)
            {
                locals.Add(choice.Decl);
            }

            List <Cmd> cmds = new List <Cmd>();

            cmds.Add(GetCallCmd(invariantAction));
            cmds.Add(CmdHelper.AssumeCmd(ExprHelper.FunctionCall(pendingAsync.pendingAsyncCtor.membership, choice)));
            cmds.Add(CmdHelper.AssumeCmd(Expr.Gt(Expr.Select(PAs, choice), Expr.Literal(0))));
            cmds.Add(RemoveChoice);

            AtomicAction abs = elim[pendingAsync];
            Dictionary <Variable, Expr> map = new Dictionary <Variable, Expr>();
            List <Expr> inputExprs          = new List <Expr>();

            for (int i = 0; i < abs.impl.InParams.Count; i++)
            {
                var pendingAsyncParam = ExprHelper.FunctionCall(pendingAsync.pendingAsyncCtor.selectors[i], choice);
                map[abs.impl.InParams[i]] = pendingAsyncParam;
                inputExprs.Add(pendingAsyncParam);
            }
            var subst = Substituter.SubstitutionFromHashtable(map);

            cmds.AddRange(GetGateAsserts(abs, subst));

            List <IdentifierExpr> outputVars = new List <IdentifierExpr>();

            if (abs.HasPendingAsyncs)
            {
                locals.Add(newPAs.Decl);
                outputVars.Add(newPAs);
            }
            cmds.Add(CmdHelper.CallCmd(abs.proc, inputExprs, outputVars));
            if (abs.HasPendingAsyncs)
            {
                cmds.Add(AddNewPAs(pendingAsyncAdd));
            }
            var blocks = new List <Block> {
                new Block(Token.NoToken, pendingAsync.proc.Name, cmds, CmdHelper.ReturnCmd)
            };

            return(GetCheckerTuple(requires, ensures, locals, blocks, "_" + abs.proc.Name));
        }
Ejemplo n.º 7
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    private static Expr PermissionMultiset(LinearDomain domain, IEnumerable<Expr> exprs)
    {
      var terms = exprs.Select(x =>
        ExprHelper.FunctionCall(domain.mapIteInt,
          ExprHelper.FunctionCall(domain.collectors[x.Type], x),
          domain.MapConstInt(1),
          domain.MapConstInt(0))).ToList<Expr>();

      if (terms.Count == 0)
        return domain.MapConstInt(0);
      return terms.Aggregate((x, y) => ExprHelper.FunctionCall(domain.mapAdd, x, y));
    }
Ejemplo n.º 8
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    private static List<Expr> PendingAsyncLinearParams(LinearTypeChecker linearTypeChecker, LinearDomain domain, AtomicAction pendingAsync, IdentifierExpr pa)
    {
      var pendingAsyncLinearParams = new List<Expr>();

      for (int i = 0; i < pendingAsync.proc.InParams.Count; i++)
      {
        var inParam = pendingAsync.proc.InParams[i];
        if (linearTypeChecker.FindDomainName(inParam) == domain.domainName && InKinds.Contains(linearTypeChecker.FindLinearKind(inParam)))
        {
          var pendingAsyncParam = ExprHelper.FunctionCall(pendingAsync.pendingAsyncCtor.selectors[i], pa);
          pendingAsyncLinearParams.Add(pendingAsyncParam);
        }
      }

      return pendingAsyncLinearParams;
    }
Ejemplo n.º 9
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            private void ComputeTransitionRelationExpr()
            {
                CalculatePathExpression();
                AddBoundVariablesForRemainingVars();
                ReplacePreOrPostStateVars();
                TransitionRelationExpr = Expr.And(pathExprs);
                if (trc.IsJoint)
                {
                    ComputeWitnessedTransitionRelationExprs();
                    if (witnessedTransitionRelations.Count > 0)
                    {
                        TransitionRelationExpr = Expr.Or(witnessedTransitionRelations);
                    }
                }

                if (existsVarMap.Any())
                {
                    Trigger trigger = null;
                    if (trc.IsJoint)
                    {
                        var exprs = new List <Expr>();
                        foreach (var v in existsVarMap.Keys)
                        {
                            var orig = copyToOriginalVar[v];
                            if (v == varCopies[orig].First() && trc.triggers.ContainsKey(orig))
                            {
                                var f = trc.triggers[orig];
                                exprs.Add(ExprHelper.FunctionCall(f, Expr.Ident(existsVarMap[v])));
                            }
                        }

                        if (exprs.Count == existsVarMap.Count)
                        {
                            trigger = new Trigger(Token.NoToken, true, exprs);
                        }
                    }

                    TransitionRelationExpr = ExprHelper.ExistsExpr(
                        existsVarMap.Values.ToList <Variable>(), trigger, TransitionRelationExpr);
                }
            }
            private void ComputeWitnessedTransitionRelationExprs()
            {
                witnessedTransitionRelations = new List <Expr>();
                Dictionary <Variable, List <CommutativityWitness> > varToWitnesses = trc.FrameWithWitnesses.
                                                                                     Where(x => NotEliminatedVars.Contains(frameIntermediateCopy[x])).
                                                                                     ToDictionary(
                    x => frameIntermediateCopy[x],
                    x => trc.globalVarToWitnesses[(GlobalVariable)x]);

                foreach (var witnessSet in varToWitnesses.Values.CartesianProduct())
                {
                    Dictionary <Variable, Expr> witnessSubst = new Dictionary <Variable, Expr>();
                    foreach (Tuple <Variable, CommutativityWitness> pair in
                             Enumerable.Zip(varToWitnesses.Keys, witnessSet, Tuple.Create))
                    {
                        CommutativityWitness witness = pair.Item2;
                        witnessSubst[pair.Item1] = ExprHelper.FunctionCall(
                            witness.function, witness.args.ToArray()
                            );
                    }
                    witnessedTransitionRelations.Add(
                        SubstitutionHelper.Apply(witnessSubst, TransitionRelationExpr));
                }
            }
Ejemplo n.º 11
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 private AssignCmd AddNewPAs(Function pendingAsyncAdd)
 {
     return(AssignCmd.SimpleAssign(Token.NoToken,
                                   PAs,
                                   ExprHelper.FunctionCall(pendingAsyncAdd, PAs, newPAs)));
 }
Ejemplo n.º 12
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 public Expr MapConstInt(int value)
 {
   return ExprHelper.FunctionCall(mapConstInt, Expr.Literal(value));
 }
Ejemplo n.º 13
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        public static void AddCheckers(CivlTypeChecker civlTypeChecker)
        {
            foreach (var action in civlTypeChecker.AllAtomicActions.Where(a => a.HasPendingAsyncs))
            {
                var requires = action.gate.Select(g => new Requires(false, g.Expr)).ToList();

                var PAs     = Expr.Ident(action.impl.OutParams.Last(p => p.TypedIdent.Type.Equals(civlTypeChecker.pendingAsyncMultisetType)));
                var paBound = civlTypeChecker.BoundVariable("pa", civlTypeChecker.pendingAsyncType);
                var pa      = Expr.Ident(paBound);

                var nonnegativeExpr =
                    ExprHelper.ForallExpr(new List <Variable> {
                    paBound
                },
                                          Expr.Ge(Expr.Select(PAs, pa), Expr.Literal(0)));
                var correctTypeExpr = ExprHelper.ForallExpr(new List <Variable> {
                    paBound
                },
                                                            Expr.Imp(
                                                                Expr.Gt(Expr.Select(PAs, pa), Expr.Literal(0)),
                                                                Expr.Or(action.pendingAsyncs.Select(a => ExprHelper.FunctionCall(a.pendingAsyncCtor.membership, pa)))));

                CivlUtil.ResolveAndTypecheck(nonnegativeExpr);
                CivlUtil.ResolveAndTypecheck(correctTypeExpr);

                var cmds = new List <Cmd>
                {
                    CmdHelper.CallCmd(
                        action.proc,
                        action.impl.InParams.Select(Expr.Ident).ToList <Expr>(),
                        action.impl.OutParams.Select(Expr.Ident).ToList()),
                    CmdHelper.AssertCmd(
                        action.proc.tok,
                        nonnegativeExpr,
                        $"Action {action.proc.Name} might create negative pending asyncs"),
                    CmdHelper.AssertCmd(
                        action.proc.tok,
                        correctTypeExpr,
                        $"Action {action.proc.Name} might create undeclared pending asyncs")
                };
                var blocks = new List <Block>()
                {
                    BlockHelper.Block("init", cmds)
                };

                var proc = DeclHelper.Procedure(civlTypeChecker.AddNamePrefix($"PendingAsyncChecker_{action.proc.Name}"),
                                                action.impl.InParams, action.impl.OutParams,
                                                requires, action.proc.Modifies, new List <Ensures>());
                var impl = DeclHelper.Implementation(proc, proc.InParams, proc.OutParams, new List <Variable>(), blocks);

                civlTypeChecker.program.AddTopLevelDeclaration(proc);
                civlTypeChecker.program.AddTopLevelDeclaration(impl);
            }
        }
Ejemplo n.º 14
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 public Expr MapEqTrue(Expr expr)
 {
   return Expr.Eq(expr, ExprHelper.FunctionCall(mapConstBool, Expr.True));
 }
Ejemplo n.º 15
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        public static void AddCheckers(CivlTypeChecker ctc)
        {
            foreach (var action in ctc.AllAtomicActions.Where(a => a.HasPendingAsyncs))
            {
                var requires = action.gate.Select(g => new Requires(false, g.Expr)).ToList();
                var cmds     = new List <Cmd>
                {
                    CmdHelper.CallCmd(
                        action.proc,
                        action.impl.InParams.Select(Expr.Ident).ToList <Expr>(),
                        action.impl.OutParams.Select(Expr.Ident).ToList())
                };
                var blocks = new List <Block>()
                {
                    new Block(Token.NoToken, "init", cmds, CmdHelper.ReturnCmd)
                };

                var PAs     = Expr.Ident(action.impl.OutParams.Last(p => p.TypedIdent.Type.Equals(ctc.pendingAsyncMultisetType)));
                var paBound = VarHelper.BoundVariable("pa", ctc.pendingAsyncType);
                var pa      = Expr.Ident(paBound);

                var nonnegativeExpr =
                    new ForallExpr(Token.NoToken, new List <Variable> {
                    paBound
                },
                                   Expr.Ge(Expr.Select(PAs, pa), Expr.Literal(0)));
                var correctTypeExpr = new ForallExpr(Token.NoToken, new List <Variable> {
                    paBound
                },
                                                     Expr.Imp(
                                                         Expr.Gt(Expr.Select(PAs, pa), Expr.Literal(0)),
                                                         Expr.Or(action.pendingAsyncs.Select(a => ExprHelper.FunctionCall(a.pendingAsyncCtor.membership, pa)))));
                var ensures = new List <Ensures>
                {
                    new Ensures(false, nonnegativeExpr)
                    {
                        ErrorData = $"Action {action.proc.Name} might create negative pending asyncs"
                    },
                    new Ensures(false, correctTypeExpr)
                    {
                        ErrorData = $"Action {action.proc.Name} might create undeclared pending asyncs"
                    },
                };

                CivlUtil.ResolveAndTypecheck(ensures);

                var proc = new Procedure(Token.NoToken, $"PendingAsyncChecker_{action.proc.Name}", new List <TypeVariable>(),
                                         action.impl.InParams, action.impl.OutParams,
                                         requires, action.proc.Modifies, ensures);
                var impl = new Implementation(Token.NoToken, proc.Name, proc.TypeParameters,
                                              proc.InParams, proc.OutParams, new List <Variable>(), blocks)
                {
                    Proc = proc
                };

                ctc.program.AddTopLevelDeclaration(proc);
                ctc.program.AddTopLevelDeclaration(impl);
            }
        }
Ejemplo n.º 16
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        private void CreateCommutativityChecker(AtomicAction first, AtomicAction second)
        {
            if (first == second && first.firstImpl.InParams.Count == 0 && first.firstImpl.OutParams.Count == 0)
            {
                return;
            }
            if (first.TriviallyCommutesWith(second))
            {
                return;
            }
            if (!commutativityCheckerCache.Add(Tuple.Create(first, second)))
            {
                return;
            }

            string checkerName = $"CommutativityChecker_{first.proc.Name}_{second.proc.Name}";

            HashSet <Variable> frame = new HashSet <Variable>();

            frame.UnionWith(first.gateUsedGlobalVars);
            frame.UnionWith(first.actionUsedGlobalVars);
            frame.UnionWith(second.gateUsedGlobalVars);
            frame.UnionWith(second.actionUsedGlobalVars);

            List <Requires> requires = new List <Requires>
            {
                DisjointnessRequires(
                    first.firstImpl.InParams.Union(second.secondImpl.InParams)
                    .Where(v => linearTypeChecker.FindLinearKind(v) != LinearKind.LINEAR_OUT),
                    frame)
            };

            foreach (AssertCmd assertCmd in Enumerable.Union(first.firstGate, second.secondGate))
            {
                requires.Add(new Requires(false, assertCmd.Expr));
            }

            var witnesses          = civlTypeChecker.commutativityHints.GetWitnesses(first, second);
            var transitionRelation = TransitionRelationComputation.Commutativity(second, first, frame, witnesses);

            List <Cmd> cmds = new List <Cmd>
            {
                new CallCmd(Token.NoToken,
                            first.proc.Name,
                            first.firstImpl.InParams.Select(Expr.Ident).ToList <Expr>(),
                            first.firstImpl.OutParams.Select(Expr.Ident).ToList()
                            )
                {
                    Proc = first.proc
                },
                new CallCmd(Token.NoToken,
                            second.proc.Name,
                            second.secondImpl.InParams.Select(Expr.Ident).ToList <Expr>(),
                            second.secondImpl.OutParams.Select(Expr.Ident).ToList()
                            )
                {
                    Proc = second.proc
                }
            };

            foreach (var lemma in civlTypeChecker.commutativityHints.GetLemmas(first, second))
            {
                cmds.Add(CmdHelper.AssumeCmd(ExprHelper.FunctionCall(lemma.function, lemma.args.ToArray())));
            }

            var block = new Block(Token.NoToken, "init", cmds, new ReturnCmd(Token.NoToken));

            var secondInParamsFiltered =
                second.secondImpl.InParams.Where(v => linearTypeChecker.FindLinearKind(v) != LinearKind.LINEAR_IN);
            IEnumerable <Expr> linearityAssumes = Enumerable.Union(
                linearTypeChecker.DisjointnessExprForEachDomain(first.firstImpl.OutParams.Union(secondInParamsFiltered)
                                                                .Union(frame)),
                linearTypeChecker.DisjointnessExprForEachDomain(first.firstImpl.OutParams.Union(second.secondImpl.OutParams)
                                                                .Union(frame)));
            // TODO: add further disjointness expressions?
            Ensures ensureCheck =
                new Ensures(first.proc.tok, false, Expr.Imp(Expr.And(linearityAssumes), transitionRelation), null)
            {
                ErrorData = $"Commutativity check between {first.proc.Name} and {second.proc.Name} failed"
            };
            List <Ensures> ensures = new List <Ensures> {
                ensureCheck
            };

            List <Variable> inputs  = Enumerable.Union(first.firstImpl.InParams, second.secondImpl.InParams).ToList();
            List <Variable> outputs = Enumerable.Union(first.firstImpl.OutParams, second.secondImpl.OutParams).ToList();

            AddChecker(checkerName, inputs, outputs, new List <Variable>(), requires, ensures, new List <Block> {
                block
            });
        }
Ejemplo n.º 17
0
    private static void AddChecker(CivlTypeChecker civlTypeChecker, Action action, List<Declaration> decls)
    {
      var linearTypeChecker = civlTypeChecker.linearTypeChecker;
      // Note: The implementation should be used as the variables in the
      //       gate are bound to implementation and not to the procedure.
      Implementation impl = action.impl;
      List<Variable> inputs = impl.InParams;
      List<Variable> outputs = impl.OutParams;

      List<Variable> locals = new List<Variable>(2);
      var paLocal1 = civlTypeChecker.LocalVariable("pa1", civlTypeChecker.pendingAsyncType);
      var paLocal2 = civlTypeChecker.LocalVariable("pa2", civlTypeChecker.pendingAsyncType);
      var pa1 = Expr.Ident(paLocal1);
      var pa2 = Expr.Ident(paLocal2);
      
      if (civlTypeChecker.pendingAsyncType != null)
      {
        locals.Add(paLocal1);
        locals.Add(paLocal2);
      }

      List<Requires> requires = action.gate.Select(a => new Requires(false, a.Expr)).ToList();
      List<LinearityCheck> linearityChecks = new List<LinearityCheck>();

      foreach (var domain in linearTypeChecker.linearDomains.Values)
      {
        // Linear in vars
        var inVars = inputs.Union(action.modifiedGlobalVars)
          .Where(x => linearTypeChecker.FindDomainName(x) == domain.domainName)
          .Where(x => InKinds.Contains(linearTypeChecker.FindLinearKind(x)))
          .Select(Expr.Ident)
          .ToList();
        
        // Linear out vars
        var outVars = inputs.Union(outputs).Union(action.modifiedGlobalVars)
          .Where(x => linearTypeChecker.FindDomainName(x) == domain.domainName)
          .Where(x => OutKinds.Contains(linearTypeChecker.FindLinearKind(x)))
          .Select(Expr.Ident)
          .ToList();

        // First kind
        // Permissions in linear output variables are a subset of permissions in linear input variables.
        if (outVars.Count > 0)
        {
          linearityChecks.Add(new LinearityCheck(
            null,
            OutPermsSubsetInPerms(domain, inVars, outVars),
            $"Potential linearity violation in outputs for domain {domain.domainName}.",
            "variables"));
        }

        if (action is AtomicAction atomicAction && atomicAction.HasPendingAsyncs)
        {
          var PAs = Expr.Ident(atomicAction.impl.OutParams.Last());
          
          foreach (var pendingAsync in atomicAction.pendingAsyncs)
          {
            var pendingAsyncLinearParams = PendingAsyncLinearParams(linearTypeChecker, domain, pendingAsync, pa1);

            if (pendingAsyncLinearParams.Count == 0) continue;

            // Second kind
            // Permissions in linear output variables + linear inputs of a single pending async
            // are a subset of permissions in linear input variables.
            var exactlyOnePA = Expr.And(
              ExprHelper.FunctionCall(pendingAsync.pendingAsyncCtor.membership, pa1),
              Expr.Eq(Expr.Select(PAs, pa1), Expr.Literal(1)));
            var outSubsetInExpr = OutPermsSubsetInPerms(domain, inVars, pendingAsyncLinearParams.Union(outVars));
            linearityChecks.Add(new LinearityCheck(
              exactlyOnePA,
              outSubsetInExpr,
              $"Potential linearity violation in outputs and pending async of {pendingAsync.proc.Name} for domain {domain.domainName}.",
              $"single_{pendingAsync.proc.Name}"));

            // Third kind
            // If there are two identical pending asyncs, then their input permissions mut be empty.
            var twoIdenticalPAs = Expr.And(
              ExprHelper.FunctionCall(pendingAsync.pendingAsyncCtor.membership, pa1),
              Expr.Ge(Expr.Select(PAs, pa1), Expr.Literal(2)));
            var emptyPerms = OutPermsSubsetInPerms(domain, Enumerable.Empty<Expr>(), pendingAsyncLinearParams);
            linearityChecks.Add(new LinearityCheck(
              twoIdenticalPAs,
              emptyPerms,
              $"Potential linearity violation in identical pending asyncs of {pendingAsync.proc.Name} for domain {domain.domainName}.",
              $"identical_{pendingAsync.proc.Name}"));
          }

          var pendingAsyncs = atomicAction.pendingAsyncs.ToList();
          for (int i = 0; i < pendingAsyncs.Count; i++)
          {
            var pendingAsync1 = pendingAsyncs[i];
            for (int j = i; j < pendingAsyncs.Count; j++)
            {
              var pendingAsync2 = pendingAsyncs[j];

              var pendingAsyncLinearParams1 = PendingAsyncLinearParams(linearTypeChecker, domain, pendingAsync1, pa1);
              var pendingAsyncLinearParams2 = PendingAsyncLinearParams(linearTypeChecker, domain, pendingAsync2, pa2);
              
              if (pendingAsyncLinearParams1.Count == 0 || pendingAsyncLinearParams2.Count == 0) continue;

              // Fourth kind
              // Input permissions of two non-identical pending asyncs (possibly of the same action)
              // are a subset of permissions in linear input variables.
              var membership = Expr.And(
                Expr.Neq(pa1, pa2),
                Expr.And(
                  ExprHelper.FunctionCall(pendingAsync1.pendingAsyncCtor.membership, pa1),
                  ExprHelper.FunctionCall(pendingAsync2.pendingAsyncCtor.membership, pa2)));

              var existing = Expr.And(
                Expr.Ge(Expr.Select(PAs, pa1), Expr.Literal(1)),
                Expr.Ge(Expr.Select(PAs, pa2), Expr.Literal(1)));

              var noDuplication = OutPermsSubsetInPerms(domain, inVars, pendingAsyncLinearParams1.Union(pendingAsyncLinearParams2));

              linearityChecks.Add(new LinearityCheck(
                Expr.And(membership, existing),
                noDuplication,
                $"Potential lnearity violation in pending asyncs of {pendingAsync1.proc.Name} and {pendingAsync2.proc.Name} for domain {domain.domainName}.",
                $"distinct_{pendingAsync1.proc.Name}_{pendingAsync2.proc.Name}"));
            }
          }
        }
      }

      if (linearityChecks.Count == 0) return;

      // Create checker blocks
      List<Block> checkerBlocks = new List<Block>(linearityChecks.Count);
      foreach (var lc in linearityChecks)
      {
        List<Cmd> cmds = new List<Cmd>(2);
        if (lc.assume != null)
        {
          cmds.Add(CmdHelper.AssumeCmd(lc.assume));
        }
        cmds.Add(new AssertCmd(action.proc.tok, lc.assert) { ErrorData = lc.message });
        var block = new Block(Token.NoToken, lc.name, cmds, CmdHelper.ReturnCmd);
        CivlUtil.ResolveAndTypecheck(block, ResolutionContext.State.Two);
        checkerBlocks.Add(block);
      }
      
      // Create init blocks
      List<Block> blocks = new List<Block>(linearityChecks.Count + 1);
      blocks.Add(
        new Block(
          Token.NoToken,
          "init",
          new List<Cmd> { CmdHelper.CallCmd(action.proc, inputs, outputs) },
          new GotoCmd(Token.NoToken, checkerBlocks)));
      blocks.AddRange(checkerBlocks);

      // Create the whole check procedure
      string checkerName = civlTypeChecker.AddNamePrefix($"LinearityChecker_{action.proc.Name}");
      Procedure linCheckerProc = new Procedure(Token.NoToken, checkerName, new List<TypeVariable>(),
        inputs, outputs, requires, action.proc.Modifies, new List<Ensures>());
      Implementation linCheckImpl = new Implementation(Token.NoToken, checkerName,
        new List<TypeVariable>(), inputs, outputs, locals, blocks);
      linCheckImpl.Proc = linCheckerProc;
      decls.Add(linCheckImpl);
      decls.Add(linCheckerProc);
    }
Ejemplo n.º 18
0
        public Tuple <Procedure, Implementation> GenerateStepChecker(Function pendingAsyncAdd)
        {
            this.checkName = "step";
            var requires = invariantAction.gate.Select(g => new Requires(false, g.Expr)).ToList();
            var ensures  = new List <Ensures> {
                GetEnsures(GetTransitionRelation(invariantAction))
            };
            var locals = new List <Variable>();

            if (elim.Values.Any(a => a.HasPendingAsyncs))
            {
                locals.Add(newPAs.Decl);
            }

            List <Block> blocks = new List <Block>();

            foreach (var pendingAsync in elim.Keys)
            {
                AtomicAction abs = elim[pendingAsync];

                Dictionary <Variable, Expr> map = new Dictionary <Variable, Expr>();
                List <Expr> inputExprs          = new List <Expr>();
                for (int i = 0; i < abs.impl.InParams.Count; i++)
                {
                    var pendingAsyncParam = ExprHelper.FunctionCall(pendingAsync.pendingAsyncCtor.selectors[i], choice);
                    map[abs.impl.InParams[i]] = pendingAsyncParam;
                    inputExprs.Add(pendingAsyncParam);
                }
                var subst = Substituter.SubstitutionFromHashtable(map);
                List <IdentifierExpr> outputVars = new List <IdentifierExpr>();
                if (abs.HasPendingAsyncs)
                {
                    outputVars.Add(newPAs);
                }

                List <Cmd> cmds = new List <Cmd>();
                cmds.Add(CmdHelper.AssumeCmd(ExprHelper.FunctionCall(pendingAsync.pendingAsyncCtor.membership, choice)));
                cmds.AddRange(GetGateAsserts(abs, subst));
                cmds.Add(CmdHelper.CallCmd(abs.proc, inputExprs, outputVars));
                if (abs.HasPendingAsyncs)
                {
                    cmds.Add(AddNewPAs(pendingAsyncAdd));
                }
                var block = new Block(Token.NoToken, pendingAsync.proc.Name, cmds, CmdHelper.ReturnCmd);
                blocks.Add(block);
            }

            {
                List <Cmd> cmds = new List <Cmd>();
                cmds.Add(GetCallCmd(invariantAction));
                if (HasChoice)
                {
                    cmds.Add(new AssumeCmd(Token.NoToken, ValidChoiceExpr));
                    cmds.Add(
                        new AssertCmd(Token.NoToken, ElimPendingAsyncExpr(choice))
                    {
                        ErrorData = $"Failed to validate choice in IS of {inputAction.proc.Name}"
                    }
                        );
                }
                else
                {
                    locals.Add(choice.Decl);
                    cmds.Add(new AssumeCmd(Token.NoToken, ElimPendingAsyncExpr(choice)));
                }
                cmds.Add(RemoveChoice);
                var initBlock = new Block(Token.NoToken, "init", cmds, new GotoCmd(Token.NoToken, blocks.ToList()));
                blocks.Insert(0, initBlock);
            }

            return(GetCheckerTuple(requires, ensures, locals, blocks));
        }