[Optimization] Parsing Smart Contract Script Analysis

src/Neo.CLI/CLI/MainService.Tools.cs

@@ -13,14 +13,14 @@
 using Neo.Cryptography.ECC;
 using Neo.IO;
 using Neo.SmartContract;
-using Neo.VM;
 using Neo.Wallets;
 using System;
 using System.Collections.Generic;
 using System.Globalization;
 using System.Linq;
 using System.Numerics;
 using System.Reflection;
+using System.Runtime.CompilerServices;
 using System.Text;
 
 namespace Neo.CLI
@@ -56,7 +56,8 @@ private void OnParseCommand(string value)
 
                 if (result != null)
                 {
-                    Console.WriteLine($"{pair.Key,-30}\t{result}");
+                    ConsoleHelper.Info("", "-----", pair.Key, "-----");
+                    ConsoleHelper.Info("", result, Environment.NewLine);
                     any = true;
                 }
             }
@@ -417,62 +418,41 @@ private static string Base64Fixed(string str)
         [ParseFunction("Base64 Smart Contract Script Analysis")]
         private string? ScriptsToOpCode(string base64)
         {
-            Script script;
             try
             {
-                var scriptData = Convert.FromBase64String(base64);
-                script = new Script(scriptData.ToArray(), true);
+                var bytes = Convert.FromBase64String(base64);
+                var sb = new StringBuilder();
+
+                foreach (var instruct in new VMInstruction(bytes))
+                {
+                    if (instruct.OperandSize == 0)
+                        sb.AppendFormat("{0:X04} {1}{2}", instruct.Position, instruct.OpCode, Environment.NewLine);
+                    else
+                        sb.AppendFormat("{0:X04} {1,-10}{2}{3}", instruct.Position, instruct.OpCode, DecodeOperand(instruct), Environment.NewLine);
+                }
+
+                return sb.ToString();
             }
-            catch (Exception)
+            catch
             {
                 return null;
             }
-            return ScriptsToOpCode(script);
         }
 
-        private string ScriptsToOpCode(Script script)
+        private string DecodeOperand(VMInstruction instruction)
         {
-            //Initialize all InteropService
-            var dic = new Dictionary<uint, string>();
-            ApplicationEngine.Services.ToList().ForEach(p => dic.Add(p.Value.Hash, p.Value.Name));
-
-            //Analyzing Scripts
-            var ip = 0;
-            Instruction instruction;
-            var result = new List<string>();
-            while (ip < script.Length && (instruction = script.GetInstruction(ip)) != null)
-            {
-                ip += instruction.Size;
-
-                var op = instruction.OpCode;
-
-                if (op.ToString().StartsWith("PUSHINT"))
-                {
-                    var operand = instruction.Operand.ToArray();
-                    result.Add($"{op} {new BigInteger(operand)}");
-                }
-                else if (op == OpCode.SYSCALL)
-                {
-                    var operand = instruction.Operand.ToArray();
-                    result.Add($"{op} {dic[BitConverter.ToUInt32(operand)]}");
-                }
-                else
-                {
-                    if (!instruction.Operand.IsEmpty && instruction.Operand.Length > 0)
-                    {
-                        var operand = instruction.Operand.ToArray();
-                        var ascii = Encoding.Default.GetString(operand);
-                        ascii = ascii.Any(p => p < '0' || p > 'z') ? operand.ToHexString() : ascii;
-
-                        result.Add($"{op} {(operand.Length == 20 ? new UInt160(operand).ToString() : ascii)}");
-                    }
-                    else
-                    {
-                        result.Add($"{op}");
-                    }
-                }
-            }
-            return Environment.NewLine + string.Join("\r\n", result.ToArray());
+            var operand = instruction.Operand[instruction.OperandPrefixSize..].ToArray();
+            var asStr = Encoding.UTF8.GetString(operand);
+            return instruction.OpCode switch
+            {
+                VM.OpCode.PUSHINT8 => $"{Unsafe.As<byte, sbyte>(ref operand[0])}",
+                VM.OpCode.PUSHINT16 => $"{Unsafe.As<byte, short>(ref operand[0])}",
+                VM.OpCode.PUSHINT32 => $"{Unsafe.As<byte, int>(ref operand[0])}",
+                VM.OpCode.PUSHINT64 => $"{Unsafe.As<byte, long>(ref operand[0])}",
+                VM.OpCode.PUSHINT128 or VM.OpCode.PUSHINT256 => $"{new BigInteger(operand)}",
+                VM.OpCode.SYSCALL => $"[{ApplicationEngine.Services[Unsafe.As<byte, uint>(ref operand[0])].Name}]",
+                _ => asStr.All(a => char.IsAscii(a)) ? $"\"{asStr}\"" : Convert.ToHexString(operand),
+            };
         }
 
         /// <summary>

src/Neo.CLI/Tools/VMInstruction.cs

@@ -0,0 +1,98 @@
+// Copyright (C) 2015-2024 The Neo Project.
+//
+// VMInstruction.cs file belongs to the neo project and is free
+// software distributed under the MIT software license, see the
+// accompanying file LICENSE in the main directory of the
+// repository or http://www.opensource.org/licenses/mit-license.php
+// for more details.
+//
+// Redistribution and use in source and binary forms with or without
+// modifications are permitted.
+
+using System;
+using System.Buffers.Binary;
+using System.Collections;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Reflection;
+
+namespace Neo.CLI
+{
+    using Neo.VM;
+
+    [DebuggerDisplay("OpCode={OpCode}, OperandSize={OperandSize}")]
+    internal sealed class VMInstruction : IEnumerable<VMInstruction>
+    {
+        private const int OpCodeSize = 1;
+
+        public int Position { get; private init; }
+        public OpCode OpCode { get; private init; }
+        public ReadOnlyMemory<byte> Operand { get; private init; }
+        public int OperandSize { get; private init; }
+        public int OperandPrefixSize { get; private init; }
+
+        private static readonly int[] s_operandSizeTable = new int[256];
+        private static readonly int[] s_operandSizePrefixTable = new int[256];
+
+        private readonly ReadOnlyMemory<byte> _script;
+
+        public VMInstruction(ReadOnlyMemory<byte> script, int start = 0)
+        {
+            if (script.IsEmpty)
+                throw new Exception("Bad Script.");
+
+            var opcode = (OpCode)script.Span[start];
+
+            if (Enum.IsDefined(opcode) == false)
+                throw new InvalidDataException($"Invalid opcode at Position: {start}.");
+
+            OperandPrefixSize = s_operandSizePrefixTable[(int)opcode];
+            OperandSize = OperandPrefixSize switch
+            {
+                0 => s_operandSizeTable[(int)opcode],
+                1 => script.Span[start + 1],
+                2 => BinaryPrimitives.ReadUInt16LittleEndian(script.Span[(start + 1)..]),
+                4 => unchecked((int)BinaryPrimitives.ReadUInt32LittleEndian(script.Span[(start + 1)..])),
+                _ => throw new InvalidDataException($"Invalid opcode prefix at Position: {start}."),
+            };
+
+            OperandSize += OperandPrefixSize;
+
+            if (start + OperandSize + OpCodeSize > script.Length)
+                throw new IndexOutOfRangeException("Operand size exceeds end of script.");
+
+            Operand = script.Slice(start + OpCodeSize, OperandSize);
+
+            _script = script;
+            OpCode = opcode;
+            Position = start;
+        }
+
+        static VMInstruction()
+        {
+            foreach (var field in typeof(OpCode).GetFields(BindingFlags.Public | BindingFlags.Static))
+            {
+                var attr = field.GetCustomAttribute<OperandSizeAttribute>();
+                if (attr == null) continue;
+
+                var index = (uint)(OpCode)field.GetValue(null)!;
+                s_operandSizeTable[index] = attr.Size;
+                s_operandSizePrefixTable[index] = attr.SizePrefix;
+            }
+        }
+
+        public IEnumerator<VMInstruction> GetEnumerator()
+        {
+            var nip = Position + OperandSize + OpCodeSize;
+            yield return this;
+
+            VMInstruction? instruct;
+            for (var ip = nip; ip < _script.Length; ip += instruct.OperandSize + OpCodeSize)
+                yield return instruct = new VMInstruction(_script, ip);
+        }
+
+        IEnumerator IEnumerable.GetEnumerator() =>
+            GetEnumerator();
+    }
+}