示例#1
0
        private void collectBoogieCmds(BoogieCmd cmd, List <BoogieCmd> cmds)
        {
            if (cmd is BoogieStructuredCmd)
            {
                if (cmd is BoogieIfCmd)
                {
                    BoogieIfCmd ifCmd = (BoogieIfCmd)cmd;
                    foreach (var c in ifCmd.ThenBody.BigBlocks[0].SimpleCmds)
                    {
                        collectBoogieCmds(c, cmds);
                    }

                    if (ifCmd.ElseBody != null)
                    {
                        foreach (var c in ifCmd.ElseBody.BigBlocks[0].SimpleCmds)
                        {
                            collectBoogieCmds(c, cmds);
                        }
                    }
                }
                else if (cmd is BoogieWhileCmd)
                {
                    BoogieWhileCmd whileCmd = (BoogieWhileCmd)cmd;
                    foreach (var c in whileCmd.Body.BigBlocks[0].SimpleCmds)
                    {
                        collectBoogieCmds(c, cmds);
                    }
                }
                else
                {
                    cmds.Add(cmd);
                }
            }
            else
            {
                cmds.Add(cmd);
            }
        }
示例#2
0
        // generate a non-deterministic choice block to call every public visible functions except constructors
        private BoogieIfCmd GenerateChoiceBlock(ContractDefinition contract)
        {
            HashSet <FunctionDefinition> funcDefs       = context.GetVisibleFunctionsByContract(contract);
            List <FunctionDefinition>    publicFuncDefs = new List <FunctionDefinition>();

            foreach (FunctionDefinition funcDef in funcDefs)
            {
                if (funcDef.IsConstructorForContract(contract.Name))
                {
                    continue;
                }
                if (funcDef.Visibility == EnumVisibility.PUBLIC || funcDef.Visibility == EnumVisibility.EXTERNAL)
                {
                    publicFuncDefs.Add(funcDef);
                }
            }
            BoogieIfCmd ifCmd = null;

            for (int i = publicFuncDefs.Count - 1; i >= 0; --i)
            {
                BoogieExpr guard = new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.EQ,
                                                             new BoogieIdentifierExpr("choice"),
                                                             new BoogieLiteralExpr(i + 1));

                BoogieStmtList thenBody = new BoogieStmtList();

                FunctionDefinition funcDef = publicFuncDefs[i];
                string             callee  = TransUtils.GetCanonicalFunctionName(funcDef, context);
                List <BoogieExpr>  inputs  = new List <BoogieExpr>()
                {
                    new BoogieIdentifierExpr("this"),
                    new BoogieIdentifierExpr("msgsender_MSG"),
                    new BoogieIdentifierExpr("msgvalue_MSG"),
                };
                foreach (VariableDeclaration param in funcDef.Parameters.Parameters)
                {
                    string name = TransUtils.GetCanonicalLocalVariableName(param);
                    inputs.Add(new BoogieIdentifierExpr(name));
                    if (param.TypeName is ArrayTypeName array)
                    {
                        thenBody.AddStatement(new BoogieCallCmd(
                                                  "FreshRefGenerator",
                                                  new List <BoogieExpr>(), new List <BoogieIdentifierExpr>()
                        {
                            new BoogieIdentifierExpr(name)
                        }));
                    }
                }

                List <BoogieIdentifierExpr> outputs = new List <BoogieIdentifierExpr>();
                var retParamCount = 0;

                foreach (VariableDeclaration param in funcDef.ReturnParameters.Parameters)
                {
                    //string name = "__ret" + funcDef.Name;
                    string name = $"__ret_{retParamCount++}_" + funcDef.Name;

                    if (!string.IsNullOrEmpty(param.Name))
                    {
                        name = TransUtils.GetCanonicalLocalVariableName(param);
                    }
                    outputs.Add(new BoogieIdentifierExpr(name));
                }

                BoogieCallCmd callCmd = new BoogieCallCmd(callee, inputs, outputs);
                thenBody.AddStatement(callCmd);

                BoogieStmtList elseBody = ifCmd == null ? null : BoogieStmtList.MakeSingletonStmtList(ifCmd);
                ifCmd = new BoogieIfCmd(guard, thenBody, elseBody);
            }
            return(ifCmd);
        }
示例#3
0
        private BoogieStmtList GenerateBodyOfFallbackDispatch(List <BoogieVariable> inParams, string fbUnknownProcName)
        {
            // Perform the payable logic to transfer balance
            //
            // Fallback(from, to, amount)
            //
            // foreach contract C that is not Lib/VeriSol
            //    if (DT[this] == C)
            //       if C has a fallback f
            //            call ret := fallBack_C(this=to, sender=from, msg.value)
            //       else
            //            assume msg.value == 0;
            // else
            //    if stubModel == callback
            //     call fallBack_unknownType(from, to, amout) //we switch the order of first two parameters to ease callbacks
            //    else if stubmodel == havoc
            //      havoc all global state, except local state of this contract
            //    else
            //      skip //default
            BoogieIfCmd ifCmd = null;

            Debug.Assert(context.ContractDefinitions.Count >= 1, "There should be at least one contract");

            List <BoogieIdentifierExpr> outParams = new List <BoogieIdentifierExpr>();

            List <BoogieExpr> unkwnFnArgs = new List <BoogieExpr>()
            {
                new BoogieIdentifierExpr(inParams[0].Name),
                new BoogieIdentifierExpr(inParams[1].Name),
                new BoogieIdentifierExpr(inParams[2].Name)
            };

            // fbUnknown(from, to, amount)
            BoogieStmtList noMatchCase = BoogieStmtList.MakeSingletonStmtList(
                new BoogieCallCmd(fbUnknownProcName, unkwnFnArgs, outParams));

            foreach (var contract in context.ContractDefinitions)
            {
                if (contract.ContractKind == EnumContractKind.LIBRARY)
                {
                    continue;
                }

                FunctionDefinition function = context.ContractToFallbackMap.ContainsKey(contract) ?
                                              context.ContractToFallbackMap[contract] : null;
                BoogieExpr lhs   = new BoogieMapSelect(new BoogieIdentifierExpr("DType"), new BoogieIdentifierExpr(inParams[1].Name));
                BoogieExpr rhs   = new BoogieIdentifierExpr(contract.Name);
                BoogieExpr guard = new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.EQ, lhs, rhs);


                BoogieStmtList thenBody = null;

                if (function != null)
                {
                    List <BoogieExpr> arguments = new List <BoogieExpr>()
                    {
                        new BoogieIdentifierExpr(inParams[1].Name),
                        new BoogieIdentifierExpr(inParams[0].Name),
                        new BoogieIdentifierExpr(inParams[2].Name)
                    };

                    string callee = TransUtils.GetCanonicalFunctionName(function, context);
                    // to.fallback(from, amount), thus need to switch param0 and param1
                    thenBody = BoogieStmtList.MakeSingletonStmtList(new BoogieCallCmd(callee, arguments, outParams));
                }
                else
                {
                    // No fallback means not payable (amount == 0)
                    thenBody = BoogieStmtList.MakeSingletonStmtList(
                        new BoogieAssumeCmd(
                            new BoogieBinaryOperation(
                                BoogieBinaryOperation.Opcode.EQ,
                                new BoogieIdentifierExpr(inParams[2].Name),
                                new BoogieLiteralExpr(BigInteger.Zero)))
                        );
                }

                BoogieStmtList elseBody = ifCmd == null ? noMatchCase : BoogieStmtList.MakeSingletonStmtList(ifCmd);

                ifCmd = new BoogieIfCmd(guard, thenBody, elseBody);
            }

            return(BoogieStmtList.MakeSingletonStmtList(ifCmd));
        }
示例#4
0
        private BoogieStmtList CreateBodyOfUnknownFallback(List <BoogieVariable> fbLocalVars, List <BoogieVariable> inParams)
        {
            Debug.Assert(context.TranslateFlags.ModelStubsAsSkips() || context.TranslateFlags.ModelStubsAsCallbacks() || context.TranslateFlags.ModelStubsAsMultipleCallbacks(),
                         "CreateBodyOfUnknownFallback called in unexpected context");
            var procBody = new BoogieStmtList();

            /*procBody.AddStatement(new BoogieCommentCmd("---- Logic for payable function START "));
             * var balnSender = new BoogieMapSelect(new BoogieIdentifierExpr("Balance"), new BoogieIdentifierExpr(inParams[0].Name));
             * var balnThis = new BoogieMapSelect(new BoogieIdentifierExpr("Balance"), new BoogieIdentifierExpr(inParams[1].Name));
             * var msgVal = new BoogieIdentifierExpr("amount");
             * //assume Balance[msg.sender] >= msg.value
             * procBody.AddStatement(new BoogieAssumeCmd(new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.GE, balnSender, msgVal)));
             * //balance[from] = balance[from] - msg.value
             * procBody.AddStatement(new BoogieAssignCmd(balnSender, new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.SUB, balnSender, msgVal)));
             * //balance[to] = balance[to] + msg.value
             * procBody.AddStatement(new BoogieAssignCmd(balnThis, new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.ADD, balnThis, msgVal)));
             * procBody.AddStatement(new BoogieCommentCmd("---- Logic for payable function END "));*/

            BoogieStmtList body = procBody;

            if (context.TranslateFlags.ModelStubsAsCallbacks() ||
                context.TranslateFlags.ModelStubsAsMultipleCallbacks())
            {
                if (context.TranslateFlags.ModelReverts)
                {
                    BoogieBinaryOperation revertGuard = new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.EQ, new BoogieIdentifierExpr("choice"), new BoogieLiteralExpr(BigInteger.Zero));
                    BoogieStmtList        thenBody    = new BoogieStmtList();
                    thenBody.AddStatement(new BoogieAssignCmd(new BoogieIdentifierExpr("revert"), new BoogieLiteralExpr(true)));
                    thenBody.AddStatement(new BoogieReturnCmd());
                    BoogieIfCmd earlyExitCmd = new BoogieIfCmd(revertGuard, thenBody, null);
                    body.AddStatement(earlyExitCmd);
                }
                if (context.TranslateFlags.InstrumentGas)
                {
                    BoogieBinaryOperation gasGuard     = new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.LT, new BoogieIdentifierExpr("gas"), new BoogieLiteralExpr(TranslatorContext.TX_GAS_COST));
                    BoogieIfCmd           earlyExitCmd = new BoogieIfCmd(gasGuard, BoogieStmtList.MakeSingletonStmtList(new BoogieReturnCmd()), null);
                    body.AddStatement(earlyExitCmd);
                }
            }

            if (context.TranslateFlags.ModelStubsAsMultipleCallbacks())
            {
                fbLocalVars.Add(new BoogieLocalVariable(new BoogieTypedIdent("iterate", BoogieType.Bool)));
                BoogieBinaryOperation gasGuard = new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.GE, new BoogieIdentifierExpr("gas"), new BoogieLiteralExpr(TranslatorContext.TX_GAS_COST));
                BoogieBinaryOperation guard    = new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.AND, new BoogieIdentifierExpr("iterate"), gasGuard);
                BoogieStmtList        loopBody = new BoogieStmtList();
                procBody.AddStatement(new BoogieWhileCmd(guard, loopBody, new List <BoogieExpr>()));
                body = loopBody;
            }

            if (context.TranslateFlags.ModelStubsAsCallbacks() || context.TranslateFlags.ModelStubsAsMultipleCallbacks())
            {
                List <BoogieVariable> localVars = TransUtils.CollectLocalVars(context.ContractDefinitions.ToList(), context);
                fbLocalVars.AddRange(localVars);
                // if (*) fn1(from, *, ...)
                // we only redirect the calling contract, but the msg.sender need not be to, as it can call into anohter contract that calls
                // into from

                if (context.TranslateFlags.ModelStubsAsMultipleCallbacks())
                {
                    body.AppendStmtList(HavocLocals(localVars));
                    body.AddStatement(new BoogieHavocCmd(new BoogieIdentifierExpr("iterate")));
                }


                BoogieIfCmd typeIf = null;
                foreach (ContractDefinition curDef in context.ContractDefinitions.ToList())
                {
                    BoogieIfCmd reentrantCalls = TransUtils.GenerateChoiceBlock(new List <ContractDefinition>()
                    {
                        curDef
                    },
                                                                                context, false, Tuple.Create(inParams[0].Name, inParams[1].Name));

                    if (reentrantCalls == null)
                    {
                        continue;
                    }

                    BoogieExpr            dtype = new BoogieMapSelect(new BoogieIdentifierExpr("DType"), new BoogieIdentifierExpr(inParams[0].Name));
                    BoogieBinaryOperation guard = new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.EQ, dtype, new BoogieIdentifierExpr(curDef.Name));
                    typeIf = new BoogieIfCmd(guard, BoogieStmtList.MakeSingletonStmtList(reentrantCalls), typeIf == null ? null : BoogieStmtList.MakeSingletonStmtList(typeIf));
                }

                /*BoogieIfCmd ifCmd = null;
                 *
                 * if (context.TranslateFlags.ModelReverts)
                 * {
                 *  BoogieExpr guard = new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.EQ,
                 *                      new BoogieIdentifierExpr("choice"),
                 *                      new BoogieLiteralExpr(choices.Item2 + 1));
                 *
                 *  BoogieAssignCmd assign = new BoogieAssignCmd(new BoogieIdentifierExpr("revert"), new BoogieLiteralExpr(true));
                 *  ifCmd = new BoogieIfCmd(guard, BoogieStmtList.MakeSingletonStmtList(assign), BoogieStmtList.MakeSingletonStmtList(choices.Item1));
                 * }
                 * else
                 * {
                 *  ifCmd = choices.Item1;
                 * }*/

                body.AddStatement(typeIf);
            }



            return(procBody);
        }
示例#5
0
        /// <summary>
        /// generate a non-deterministic choice block to call every public visible functions except constructors
        ///
        /// </summary>
        /// <param name="contracts"></param>
        /// <param name="context"></param>
        /// <param name="callBackTarget">If non-null, this will be the msg.sender for calling back into the contracts</param>
        /// <returns></returns>
        public static BoogieIfCmd GenerateChoiceBlock(List <ContractDefinition> contracts, TranslatorContext context, Tuple <string, string> callBackTarget = null)
        {
            BoogieIfCmd ifCmd = null;
            int         j     = 0;

            foreach (var contract in contracts)
            {
                if (contract.ContractKind != EnumContractKind.CONTRACT)
                {
                    continue;
                }

                HashSet <FunctionDefinition> funcDefs       = context.GetVisibleFunctionsByContract(contract);
                List <FunctionDefinition>    publicFuncDefs = new List <FunctionDefinition>();
                foreach (FunctionDefinition funcDef in funcDefs)
                {
                    if (funcDef.IsConstructor)
                    {
                        continue;
                    }
                    if (funcDef.IsFallback)
                    {
                        continue;                     //let us not call fallback directly in harness
                    }
                    if (funcDef.Visibility == EnumVisibility.PUBLIC || funcDef.Visibility == EnumVisibility.EXTERNAL)
                    {
                        publicFuncDefs.Add(funcDef);
                    }
                }
                for (int i = publicFuncDefs.Count - 1; i >= 0; --i)
                {
                    j++;
                    BoogieExpr guard = new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.EQ,
                                                                 new BoogieIdentifierExpr("choice"),
                                                                 new BoogieLiteralExpr(j));

                    BoogieStmtList thenBody = new BoogieStmtList();

                    FunctionDefinition funcDef = publicFuncDefs[i];
                    string             callee  = TransUtils.GetCanonicalFunctionName(funcDef, context);
                    List <BoogieExpr>  inputs  = new List <BoogieExpr>()
                    {
                        // let us just call back into the calling contract
                        callBackTarget != null ? new BoogieIdentifierExpr(callBackTarget.Item1) : new BoogieIdentifierExpr("this"),
                        callBackTarget != null ? new BoogieIdentifierExpr(callBackTarget.Item2) : new BoogieIdentifierExpr("msgsender_MSG"),
                        new BoogieIdentifierExpr("msgvalue_MSG"),
                    };
                    foreach (VariableDeclaration param in funcDef.Parameters.Parameters)
                    {
                        string name = TransUtils.GetCanonicalLocalVariableName(param);
                        inputs.Add(new BoogieIdentifierExpr(name));
                        if (param.TypeName is ArrayTypeName array)
                        {
                            thenBody.AddStatement(new BoogieCallCmd(
                                                      "FreshRefGenerator",
                                                      new List <BoogieExpr>(), new List <BoogieIdentifierExpr>()
                            {
                                new BoogieIdentifierExpr(name)
                            }));
                        }
                    }

                    List <BoogieIdentifierExpr> outputs = new List <BoogieIdentifierExpr>();
                    var retParamCount = 0;

                    foreach (VariableDeclaration param in funcDef.ReturnParameters.Parameters)
                    {
                        string name = $"__ret_{retParamCount++}_" + funcDef.Name;
                        if (!string.IsNullOrEmpty(param.Name))
                        {
                            name = TransUtils.GetCanonicalLocalVariableName(param);
                        }
                        outputs.Add(new BoogieIdentifierExpr(name));
                    }

                    if (context.TranslateFlags.InstrumentGas)
                    {
                        havocGas(thenBody);
                    }
                    BoogieCallCmd callCmd = new BoogieCallCmd(callee, inputs, outputs);
                    thenBody.AddStatement(callCmd);

                    BoogieStmtList elseBody = ifCmd == null ? null : BoogieStmtList.MakeSingletonStmtList(ifCmd);
                    ifCmd = new BoogieIfCmd(guard, thenBody, elseBody);
                }
            }
            return(ifCmd);
        }
示例#6
0
        private BoogieStmtList GenerateBody(List <BoogieVariable> inParams)
        {
            //
            // foreach contract C that is not Lib/VeriSol
            //    if (DT[this] == C)
            //       if C has a fallback f
            //            call ret := fallBack_C(this=to, sender=from, msg.value)
            //       else
            //            assume msg.value == 0;
            // else
            //     call fallBack_unknownType(from, to, msg.value)
            BoogieIfCmd ifCmd = null;

            Debug.Assert(context.ContractDefinitions.Count >= 1, "There should be at least one contract");

            List <BoogieExpr> arguments = new List <BoogieExpr>()
            {
                new BoogieIdentifierExpr(inParams[1].Name),
                new BoogieIdentifierExpr(inParams[0].Name),
                new BoogieIdentifierExpr(inParams[2].Name)
            };
            List <BoogieIdentifierExpr> outParams = new List <BoogieIdentifierExpr>();

            BoogieStmtList noMatchCase = BoogieStmtList.MakeSingletonStmtList(
                new BoogieCallCmd("Fallback_UnknownType", arguments, outParams));

            foreach (var contract in context.ContractDefinitions)
            {
                if (contract.ContractKind == EnumContractKind.LIBRARY)
                {
                    continue;
                }


                FunctionDefinition function = context.ContractToFallbackMap.ContainsKey(contract) ?
                                              context.ContractToFallbackMap[contract] : null;
                BoogieExpr lhs   = new BoogieMapSelect(new BoogieIdentifierExpr("DType"), new BoogieIdentifierExpr(inParams[1].Name));
                BoogieExpr rhs   = new BoogieIdentifierExpr(contract.Name);
                BoogieExpr guard = new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.EQ, lhs, rhs);


                BoogieStmtList thenBody = null;

                if (function != null)
                {
                    string callee = TransUtils.GetCanonicalFunctionName(function, context);
                    thenBody = BoogieStmtList.MakeSingletonStmtList(new BoogieCallCmd(callee, arguments, outParams));
                }
                else
                {
                    // No fallback means not payable (amount == 0)
                    thenBody = BoogieStmtList.MakeSingletonStmtList(
                        new BoogieAssumeCmd(
                            new BoogieBinaryOperation(
                                BoogieBinaryOperation.Opcode.EQ,
                                new BoogieIdentifierExpr(inParams[2].Name),
                                new BoogieLiteralExpr(BigInteger.Zero)))
                        );
                }

                BoogieStmtList elseBody = ifCmd == null ? noMatchCase : BoogieStmtList.MakeSingletonStmtList(ifCmd);

                ifCmd = new BoogieIfCmd(guard, thenBody, elseBody);
            }


            return(BoogieStmtList.MakeSingletonStmtList(ifCmd));
        }
示例#7
0
        public static Tuple <BoogieIfCmd, int> GeneratePartialChoiceBlock(List <ContractDefinition> contracts, TranslatorContext context, BoogieExpr thisExpr, int startingPoint, bool canRevert, BoogieIfCmd alternatives = null, Tuple <string, string> callBackTarget = null)
        {
            BoogieIfCmd ifCmd = alternatives;
            int         j     = startingPoint;

            foreach (var contract in contracts)
            {
                if (contract.ContractKind != EnumContractKind.CONTRACT)
                {
                    continue;
                }

                HashSet <FunctionDefinition> funcDefs       = context.GetVisibleFunctionsByContract(contract);
                List <FunctionDefinition>    publicFuncDefs = new List <FunctionDefinition>();
                foreach (FunctionDefinition funcDef in funcDefs)
                {
                    if (funcDef.IsConstructor)
                    {
                        continue;
                    }
                    if (funcDef.IsFallback)
                    {
                        continue;                     //let us not call fallback directly in harness
                    }
                    if (context.TranslateFlags.PerformFunctionSlice &&
                        !context.TranslateFlags.SliceFunctions.Contains(funcDef))
                    {
                        continue;
                    }

                    if (funcDef.Visibility == EnumVisibility.PUBLIC || funcDef.Visibility == EnumVisibility.EXTERNAL)
                    {
                        publicFuncDefs.Add(funcDef);
                    }
                }
                for (int i = publicFuncDefs.Count - 1; i >= 0; --i)
                {
                    j++;
                    BoogieExpr guard = new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.EQ,
                                                                 new BoogieIdentifierExpr("choice"),
                                                                 new BoogieLiteralExpr(j));

                    BoogieStmtList thenBody = new BoogieStmtList();

                    FunctionDefinition funcDef = publicFuncDefs[i];
                    string             callee  = TransUtils.GetCanonicalFunctionName(funcDef, context);
                    List <BoogieExpr>  inputs  = new List <BoogieExpr>()
                    {
                        // let us just call back into the calling contract
                        callBackTarget != null ? new BoogieIdentifierExpr(callBackTarget.Item1) : thisExpr,
                        callBackTarget != null ? new BoogieIdentifierExpr(callBackTarget.Item2) : new BoogieIdentifierExpr("msgsender_MSG"),
                        new BoogieIdentifierExpr("msgvalue_MSG"),
                    };
                    var inpParamCount = 0;
                    foreach (VariableDeclaration param in funcDef.Parameters.Parameters)
                    {
                        string name = $"__arg_{inpParamCount++}_" + funcDef.Name;
                        if (!string.IsNullOrEmpty(param.Name))
                        {
                            name = TransUtils.GetCanonicalLocalVariableName(param, context);
                        }

                        BoogieIdentifierExpr boogieVar = new BoogieIdentifierExpr(name);
                        inputs.Add(boogieVar);
                        if (param.TypeName is ArrayTypeName array)
                        {
                            thenBody.AddStatement(new BoogieCallCmd(
                                                      "FreshRefGenerator",
                                                      new List <BoogieExpr>(), new List <BoogieIdentifierExpr>()
                            {
                                new BoogieIdentifierExpr(name)
                            }));
                        }

                        thenBody.AppendStmtList(constrainVarValues(context, param, boogieVar));
                    }

                    List <BoogieIdentifierExpr> outputs = new List <BoogieIdentifierExpr>();
                    var retParamCount = 0;

                    foreach (VariableDeclaration param in funcDef.ReturnParameters.Parameters)
                    {
                        string name = $"__ret_{retParamCount++}_" + funcDef.Name;
                        if (!string.IsNullOrEmpty(param.Name))
                        {
                            name = TransUtils.GetCanonicalLocalVariableName(param, context);
                        }

                        outputs.Add(new BoogieIdentifierExpr(name));
                    }

                    if (funcDef.StateMutability.Equals(EnumStateMutability.PAYABLE))
                    {
                        BoogieExpr assumeExpr = new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.GE,
                                                                          new BoogieIdentifierExpr("msgvalue_MSG"), new BoogieLiteralExpr(BigInteger.Zero));
                        thenBody.AddStatement(new BoogieAssumeCmd(assumeExpr));

                        if (!canRevert)
                        {
                            thenBody.AddStatement(new BoogieCommentCmd("---- Logic for payable function START "));
                            var balnSender = new BoogieMapSelect(new BoogieIdentifierExpr("Balance"), new BoogieIdentifierExpr("msgsender_MSG"));
                            var balnThis   = new BoogieMapSelect(new BoogieIdentifierExpr("Balance"), new BoogieIdentifierExpr("this"));
                            var msgVal     = new BoogieIdentifierExpr("msgvalue_MSG");
                            //assume Balance[msg.sender] >= msg.value
                            thenBody.AddStatement(new BoogieAssumeCmd(new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.GE, balnSender, msgVal)));
                            //balance[msg.sender] = balance[msg.sender] - msg.value
                            thenBody.AddStatement(new BoogieAssignCmd(balnSender, new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.SUB, balnSender, msgVal)));
                            //balance[this] = balance[this] + msg.value
                            thenBody.AddStatement(new BoogieAssignCmd(balnThis, new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.ADD, balnThis, msgVal)));
                            thenBody.AddStatement(new BoogieCommentCmd("---- Logic for payable function END "));
                        }
                    }
                    else
                    {
                        BoogieExpr assumeExpr = new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.EQ,
                                                                          new BoogieIdentifierExpr("msgvalue_MSG"), new BoogieLiteralExpr(BigInteger.Zero));
                        thenBody.AddStatement(new BoogieAssumeCmd(assumeExpr));
                    }

                    BoogieCallCmd callCmd = new BoogieCallCmd(callee, inputs, outputs);
                    thenBody.AddStatement(callCmd);

                    if (context.TranslateFlags.InstrumentGas)
                    {
                        var gasVar = new BoogieIdentifierExpr("gas");

                        BoogieBinaryOperation gasGuard = new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.GE, gasVar, new BoogieLiteralExpr(BigInteger.Zero));

                        BoogieIfCmd ifExpr = new BoogieIfCmd(gasGuard, thenBody, null);

                        thenBody = new BoogieStmtList();
                        //thenBody.AddStatement(new BoogieAssumeCmd(new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.GE, gasVar, new BoogieLiteralExpr(TranslatorContext.TX_GAS_COST))));
                        thenBody.AddStatement(new BoogieAssignCmd(gasVar, new BoogieBinaryOperation(BoogieBinaryOperation.Opcode.SUB, gasVar, new BoogieLiteralExpr(TranslatorContext.TX_GAS_COST))));
                        thenBody.AddStatement(ifExpr);
                    }

                    BoogieStmtList elseBody = ifCmd == null ? null : BoogieStmtList.MakeSingletonStmtList(ifCmd);
                    ifCmd = new BoogieIfCmd(guard, thenBody, elseBody);
                }
            }
            return(new Tuple <BoogieIfCmd, int>(ifCmd, j));
        }