Always return a value for public methods (neo-project#1706)

src/neo/Ledger/Blockchain.cs

@@ -91,7 +91,10 @@ static Blockchain()
             using (ScriptBuilder sb = new ScriptBuilder())
             {
                 foreach (NativeContract contract in contracts)
-                    sb.EmitAppCall(contract.Hash, ContractParameterType.Boolean, "onPersist");
+                {
+                    sb.EmitAppCall(contract.Hash, "onPersist");
+                    sb.Emit(OpCode.DROP);
+                }
 
                 onPersistNativeContractScript = sb.ToArray();
             }

src/neo/SmartContract/ApplicationEngine.Contract.cs

@@ -100,19 +100,19 @@ internal void DestroyContract()
                     Snapshot.Storages.Delete(key);
         }
 
-        internal void CallContract(UInt160 contractHash, ContractParameterType returnType, string method, Array args)
+        internal void CallContract(UInt160 contractHash, string method, Array args)
         {
-            CallContractInternal(contractHash, returnType, method, args, CallFlags.All);
+            CallContractInternal(contractHash, method, args, CallFlags.All);
         }
 
-        internal void CallContractEx(UInt160 contractHash, ContractParameterType returnType, string method, Array args, CallFlags callFlags)
+        internal void CallContractEx(UInt160 contractHash, string method, Array args, CallFlags callFlags)
         {
             if ((callFlags & ~CallFlags.All) != 0)
                 throw new ArgumentOutOfRangeException(nameof(callFlags));
-            CallContractInternal(contractHash, returnType, method, args, callFlags);
+            CallContractInternal(contractHash, method, args, callFlags);
         }
 
-        private void CallContractInternal(UInt160 contractHash, ContractParameterType returnType, string method, Array args, CallFlags flags)
+        private void CallContractInternal(UInt160 contractHash, string method, Array args, CallFlags flags)
         {
             if (method.StartsWith('_')) throw new ArgumentException();
 
@@ -140,15 +140,10 @@ private void CallContractInternal(UInt160 contractHash, ContractParameterType re
             ContractMethodDescriptor md = contract.Manifest.Abi.GetMethod(method);
             if (md is null) throw new InvalidOperationException();
             if (args.Count != md.Parameters.Length) throw new InvalidOperationException();
-            if (returnType == ContractParameterType.Void && md.ReturnType != ContractParameterType.Void)
-                throw new InvalidOperationException();
-            if (returnType != ContractParameterType.Any && md.ReturnType != returnType)
-                throw new InvalidOperationException();
             ExecutionContext context_new = LoadScript(contract.Script);
             state = context_new.GetState<ExecutionContextState>();
             state.CallingScriptHash = callingScriptHash;
             state.CallFlags = flags & callingFlags;
-            state.RVCount = returnType == ContractParameterType.Void ? 0 : 1;
 
             if (NativeContract.IsNative(contractHash))
             {

src/neo/SmartContract/ApplicationEngine.cs

@@ -58,10 +58,9 @@ internal bool AddGas(long gas)
         protected override void ContextUnloaded(ExecutionContext context)
         {
             base.ContextUnloaded(context);
-            if (context.EvaluationStack == CurrentContext?.EvaluationStack) return;
-            int rvcount = context.GetState<ExecutionContextState>().RVCount;
-            if (rvcount != -1 && rvcount != context.EvaluationStack.Count)
-                throw new InvalidOperationException();
+            if (CurrentContext != null && context.EvaluationStack != CurrentContext.EvaluationStack)
+                if (context.EvaluationStack.Count == 0)
+                    Push(StackItem.Null);
         }
 
         protected override void LoadContext(ExecutionContext context)

src/neo/SmartContract/ExecutionContextState.cs

@@ -16,7 +16,5 @@ internal class ExecutionContextState
         /// Execution context rights
         /// </summary>
         public CallFlags CallFlags { get; set; } = CallFlags.All;
-
-        public int RVCount { get; set; } = -1;
     }
 }

src/neo/SmartContract/Native/NativeContract.cs

@@ -151,7 +151,7 @@ public ApplicationEngine TestCall(string operation, params object[] args)
         {
             using (ScriptBuilder sb = new ScriptBuilder())
             {
-                sb.EmitAppCall(Hash, ContractParameterType.Any, operation, args);
+                sb.EmitAppCall(Hash, operation, args);
                 return ApplicationEngine.Run(sb.ToArray(), testMode: true);
             }
         }

src/neo/VM/Helper.cs

@@ -23,38 +23,35 @@ public static ScriptBuilder Emit(this ScriptBuilder sb, params OpCode[] ops)
             return sb;
         }
 
-        public static ScriptBuilder EmitAppCall(this ScriptBuilder sb, UInt160 scriptHash, ContractParameterType returnType, string operation)
+        public static ScriptBuilder EmitAppCall(this ScriptBuilder sb, UInt160 scriptHash, string operation)
         {
             sb.EmitPush(0);
             sb.Emit(OpCode.NEWARRAY);
             sb.EmitPush(operation);
-            sb.EmitPush(returnType);
             sb.EmitPush(scriptHash);
             sb.EmitSysCall(ApplicationEngine.System_Contract_Call);
             return sb;
         }
 
-        public static ScriptBuilder EmitAppCall(this ScriptBuilder sb, UInt160 scriptHash, ContractParameterType returnType, string operation, params ContractParameter[] args)
+        public static ScriptBuilder EmitAppCall(this ScriptBuilder sb, UInt160 scriptHash, string operation, params ContractParameter[] args)
         {
             for (int i = args.Length - 1; i >= 0; i--)
                 sb.EmitPush(args[i]);
             sb.EmitPush(args.Length);
             sb.Emit(OpCode.PACK);
             sb.EmitPush(operation);
-            sb.EmitPush(returnType);
             sb.EmitPush(scriptHash);
             sb.EmitSysCall(ApplicationEngine.System_Contract_Call);
             return sb;
         }
 
-        public static ScriptBuilder EmitAppCall(this ScriptBuilder sb, UInt160 scriptHash, ContractParameterType returnType, string operation, params object[] args)
+        public static ScriptBuilder EmitAppCall(this ScriptBuilder sb, UInt160 scriptHash, string operation, params object[] args)
         {
             for (int i = args.Length - 1; i >= 0; i--)
                 sb.EmitPush(args[i]);
             sb.EmitPush(args.Length);
             sb.Emit(OpCode.PACK);
             sb.EmitPush(operation);
-            sb.EmitPush(returnType);
             sb.EmitPush(scriptHash);
             sb.EmitSysCall(ApplicationEngine.System_Contract_Call);
             return sb;
@@ -211,14 +208,14 @@ public static string GetString(this StackItem item)
         /// <param name="operation">contract operation</param>
         /// <param name="args">operation arguments</param>
         /// <returns></returns>
-        public static byte[] MakeScript(this UInt160 scriptHash, ContractParameterType returnType, string operation, params object[] args)
+        public static byte[] MakeScript(this UInt160 scriptHash, string operation, params object[] args)
         {
             using (ScriptBuilder sb = new ScriptBuilder())
             {
                 if (args.Length > 0)
-                    sb.EmitAppCall(scriptHash, returnType, operation, args);
+                    sb.EmitAppCall(scriptHash, operation, args);
                 else
-                    sb.EmitAppCall(scriptHash, returnType, operation);
+                    sb.EmitAppCall(scriptHash, operation);
                 return sb.ToArray();
             }
         }

src/neo/Wallets/AssetDescriptor.cs

@@ -15,8 +15,8 @@ public AssetDescriptor(UInt160 asset_id)
             byte[] script;
             using (ScriptBuilder sb = new ScriptBuilder())
             {
-                sb.EmitAppCall(asset_id, ContractParameterType.Integer, "decimals");
-                sb.EmitAppCall(asset_id, ContractParameterType.String, "name");
+                sb.EmitAppCall(asset_id, "decimals");
+                sb.EmitAppCall(asset_id, "name");
                 script = sb.ToArray();
             }
             using ApplicationEngine engine = ApplicationEngine.Run(script, extraGAS: 3_000_000);

src/neo/Wallets/Wallet.cs

@@ -137,10 +137,10 @@ public BigDecimal GetBalance(UInt160 asset_id, params UInt160[] accounts)
                 sb.EmitPush(0);
                 foreach (UInt160 account in accounts)
                 {
-                    sb.EmitAppCall(asset_id, ContractParameterType.Integer, "balanceOf", account);
+                    sb.EmitAppCall(asset_id, "balanceOf", account);
                     sb.Emit(OpCode.ADD);
                 }
-                sb.EmitAppCall(asset_id, ContractParameterType.Integer, "decimals");
+                sb.EmitAppCall(asset_id, "decimals");
                 script = sb.ToArray();
             }
             using ApplicationEngine engine = ApplicationEngine.Run(script, extraGAS: 20000000L * accounts.Length);
@@ -246,7 +246,7 @@ public Transaction MakeTransaction(TransferOutput[] outputs, UInt160 from = null
                         foreach (UInt160 account in accounts)
                             using (ScriptBuilder sb2 = new ScriptBuilder())
                             {
-                                sb2.EmitAppCall(assetId, ContractParameterType.Integer, "balanceOf", account);
+                                sb2.EmitAppCall(assetId, "balanceOf", account);
                                 using (ApplicationEngine engine = ApplicationEngine.Run(sb2.ToArray(), snapshot, testMode: true))
                                 {
                                     if (engine.State.HasFlag(VMState.FAULT))
@@ -265,7 +265,7 @@ public Transaction MakeTransaction(TransferOutput[] outputs, UInt160 from = null
                             cosignerList.UnionWith(balances_used.Select(p => p.Account));
                             foreach (var (account, value) in balances_used)
                             {
-                                sb.EmitAppCall(output.AssetId, ContractParameterType.Boolean, "transfer", account, output.ScriptHash, value);
+                                sb.EmitAppCall(output.AssetId, "transfer", account, output.ScriptHash, value);
                                 sb.Emit(OpCode.ASSERT);
                             }
                         }

tests/neo.UnitTests/Network/P2P/Payloads/UT_Transaction.cs

@@ -158,8 +158,8 @@ public void FeeIsMultiSigContract()
 
                 var sizeGas = tx.Size * NativeContract.Policy.GetFeePerByte(snapshot);
                 Assert.AreEqual(2000810, verificationGas);
-                Assert.AreEqual(368000, sizeGas);
-                Assert.AreEqual(2368810, tx.NetworkFee);
+                Assert.AreEqual(367000, sizeGas);
+                Assert.AreEqual(2367810, tx.NetworkFee);
             }
         }
 
@@ -200,7 +200,7 @@ public void FeeIsSignatureContractDetailed()
                 Assert.IsNull(tx.Witnesses);
 
                 // check pre-computed network fee (already guessing signature sizes)
-                tx.NetworkFee.Should().Be(1265390);
+                tx.NetworkFee.Should().Be(1264390);
 
                 // ----
                 // Sign
@@ -242,7 +242,7 @@ public void FeeIsSignatureContractDetailed()
                 // ------------------
                 // check tx_size cost
                 // ------------------
-                Assert.AreEqual(265, tx.Size);
+                Assert.AreEqual(264, tx.Size);
 
                 // will verify tx size, step by step
 
@@ -256,18 +256,18 @@ public void FeeIsSignatureContractDetailed()
                 // Note that Data size and Usage size are different (because of first byte on GetVarSize())
                 Assert.AreEqual(22, tx.Cosigners.Values.First().Size);
                 // Part III
-                Assert.AreEqual(87, tx.Script.GetVarSize());
+                Assert.AreEqual(86, tx.Script.GetVarSize());
                 // Part IV
                 Assert.AreEqual(110, tx.Witnesses.GetVarSize());
                 // I + II + III + IV
-                Assert.AreEqual(45 + 23 + 87 + 110, tx.Size);
+                Assert.AreEqual(45 + 23 + 86 + 110, tx.Size);
 
                 Assert.AreEqual(1000, NativeContract.Policy.GetFeePerByte(snapshot));
                 var sizeGas = tx.Size * NativeContract.Policy.GetFeePerByte(snapshot);
-                Assert.AreEqual(265000, sizeGas);
+                Assert.AreEqual(264000, sizeGas);
 
                 // final check on sum: verification_cost + tx_size
-                Assert.AreEqual(1265390, verificationGas + sizeGas);
+                Assert.AreEqual(1264390, verificationGas + sizeGas);
                 // final assert
                 Assert.AreEqual(tx.NetworkFee, verificationGas + sizeGas);
             }
@@ -302,7 +302,7 @@ public void FeeIsSignatureContract_TestScope_Global()
                 {
                     // self-transfer of 1e-8 GAS
                     System.Numerics.BigInteger value = (new BigDecimal(1, 8)).Value;
-                    sb.EmitAppCall(NativeContract.GAS.Hash, ContractParameterType.Boolean, "transfer", acc.ScriptHash, acc.ScriptHash, value);
+                    sb.EmitAppCall(NativeContract.GAS.Hash, "transfer", acc.ScriptHash, acc.ScriptHash, value);
                     sb.Emit(OpCode.ASSERT);
                     script = sb.ToArray();
                 }
@@ -353,7 +353,7 @@ public void FeeIsSignatureContract_TestScope_Global()
                 // get sizeGas
                 var sizeGas = tx.Size * NativeContract.Policy.GetFeePerByte(snapshot);
                 // final check on sum: verification_cost + tx_size
-                Assert.AreEqual(1265390, verificationGas + sizeGas);
+                Assert.AreEqual(1264390, verificationGas + sizeGas);
                 // final assert
                 Assert.AreEqual(tx.NetworkFee, verificationGas + sizeGas);
             }
@@ -388,7 +388,7 @@ public void FeeIsSignatureContract_TestScope_CurrentHash_GAS()
                 {
                     // self-transfer of 1e-8 GAS
                     System.Numerics.BigInteger value = (new BigDecimal(1, 8)).Value;
-                    sb.EmitAppCall(NativeContract.GAS.Hash, ContractParameterType.Boolean, "transfer", acc.ScriptHash, acc.ScriptHash, value);
+                    sb.EmitAppCall(NativeContract.GAS.Hash, "transfer", acc.ScriptHash, acc.ScriptHash, value);
                     sb.Emit(OpCode.ASSERT);
                     script = sb.ToArray();
                 }
@@ -440,7 +440,7 @@ public void FeeIsSignatureContract_TestScope_CurrentHash_GAS()
                 // get sizeGas
                 var sizeGas = tx.Size * NativeContract.Policy.GetFeePerByte(snapshot);
                 // final check on sum: verification_cost + tx_size
-                Assert.AreEqual(1286390, verificationGas + sizeGas);
+                Assert.AreEqual(1285390, verificationGas + sizeGas);
                 // final assert
                 Assert.AreEqual(tx.NetworkFee, verificationGas + sizeGas);
             }
@@ -475,7 +475,7 @@ public void FeeIsSignatureContract_TestScope_CalledByEntry_Plus_GAS()
                 {
                     // self-transfer of 1e-8 GAS
                     System.Numerics.BigInteger value = (new BigDecimal(1, 8)).Value;
-                    sb.EmitAppCall(NativeContract.GAS.Hash, ContractParameterType.Boolean, "transfer", acc.ScriptHash, acc.ScriptHash, value);
+                    sb.EmitAppCall(NativeContract.GAS.Hash, "transfer", acc.ScriptHash, acc.ScriptHash, value);
                     sb.Emit(OpCode.ASSERT);
                     script = sb.ToArray();
                 }
@@ -530,7 +530,7 @@ public void FeeIsSignatureContract_TestScope_CalledByEntry_Plus_GAS()
                 // get sizeGas
                 var sizeGas = tx.Size * NativeContract.Policy.GetFeePerByte(snapshot);
                 // final check on sum: verification_cost + tx_size
-                Assert.AreEqual(1286390, verificationGas + sizeGas);
+                Assert.AreEqual(1285390, verificationGas + sizeGas);
                 // final assert
                 Assert.AreEqual(tx.NetworkFee, verificationGas + sizeGas);
             }
@@ -563,7 +563,7 @@ public void FeeIsSignatureContract_TestScope_CurrentHash_NEO_FAULT()
                 {
                     // self-transfer of 1e-8 GAS
                     System.Numerics.BigInteger value = (new BigDecimal(1, 8)).Value;
-                    sb.EmitAppCall(NativeContract.GAS.Hash, ContractParameterType.Boolean, "transfer", acc.ScriptHash, acc.ScriptHash, value);
+                    sb.EmitAppCall(NativeContract.GAS.Hash, "transfer", acc.ScriptHash, acc.ScriptHash, value);
                     sb.Emit(OpCode.ASSERT);
                     script = sb.ToArray();
                 }
@@ -615,7 +615,7 @@ public void FeeIsSignatureContract_TestScope_CurrentHash_NEO_GAS()
                 {
                     // self-transfer of 1e-8 GAS
                     System.Numerics.BigInteger value = (new BigDecimal(1, 8)).Value;
-                    sb.EmitAppCall(NativeContract.GAS.Hash, ContractParameterType.Boolean, "transfer", acc.ScriptHash, acc.ScriptHash, value);
+                    sb.EmitAppCall(NativeContract.GAS.Hash, "transfer", acc.ScriptHash, acc.ScriptHash, value);
                     sb.Emit(OpCode.ASSERT);
                     script = sb.ToArray();
                 }
@@ -672,7 +672,7 @@ public void FeeIsSignatureContract_TestScope_CurrentHash_NEO_GAS()
                 // get sizeGas
                 var sizeGas = tx.Size * NativeContract.Policy.GetFeePerByte(snapshot);
                 // final check on sum: verification_cost + tx_size
-                Assert.AreEqual(1306390, verificationGas + sizeGas);
+                Assert.AreEqual(1305390, verificationGas + sizeGas);
                 // final assert
                 Assert.AreEqual(tx.NetworkFee, verificationGas + sizeGas);
             }
@@ -705,7 +705,7 @@ public void FeeIsSignatureContract_TestScope_NoScopeFAULT()
                 {
                     // self-transfer of 1e-8 GAS
                     System.Numerics.BigInteger value = (new BigDecimal(1, 8)).Value;
-                    sb.EmitAppCall(NativeContract.GAS.Hash, ContractParameterType.Boolean, "transfer", acc.ScriptHash, acc.ScriptHash, value);
+                    sb.EmitAppCall(NativeContract.GAS.Hash, "transfer", acc.ScriptHash, acc.ScriptHash, value);
                     sb.Emit(OpCode.ASSERT);
                     script = sb.ToArray();
                 }
@@ -953,7 +953,7 @@ public void FeeIsSignatureContract_TestScope_Global_Default()
                 {
                     // self-transfer of 1e-8 GAS
                     System.Numerics.BigInteger value = (new BigDecimal(1, 8)).Value;
-                    sb.EmitAppCall(NativeContract.GAS.Hash, ContractParameterType.Boolean, "transfer", acc.ScriptHash, acc.ScriptHash, value);
+                    sb.EmitAppCall(NativeContract.GAS.Hash, "transfer", acc.ScriptHash, acc.ScriptHash, value);
                     sb.Emit(OpCode.ASSERT);
                     script = sb.ToArray();
                 }
@@ -1003,7 +1003,7 @@ public void FeeIsSignatureContract_TestScope_Global_Default()
                 // get sizeGas
                 var sizeGas = tx.Size * NativeContract.Policy.GetFeePerByte(snapshot);
                 // final check on sum: verification_cost + tx_size
-                Assert.AreEqual(1265390, verificationGas + sizeGas);
+                Assert.AreEqual(1264390, verificationGas + sizeGas);
                 // final assert
                 Assert.AreEqual(tx.NetworkFee, verificationGas + sizeGas);
             }

tests/neo.UnitTests/SmartContract/Native/Tokens/UT_NeoToken.cs

@@ -448,7 +448,7 @@ public void TestVote()
                 }));
             }
 
-            sb.EmitAppCall(NativeContract.NEO.Hash, ContractParameterType.Boolean, "transfer", from, UInt160.Zero, amount);
+            sb.EmitAppCall(NativeContract.NEO.Hash, "transfer", from, UInt160.Zero, amount);
             engine.LoadScript(sb.ToArray());
             engine.Execute();
             var result = engine.ResultStack.Peek();