Stack Isolation

src/neo-vm/ExecutionContext.cs

@@ -1,16 +1,17 @@
 using System;
-using System.Collections.Generic;
 using System.IO;
 
 namespace Neo.VM
 {
     public class ExecutionContext : IDisposable
     {
-        private ExecutionEngine engine;
         public readonly byte[] Script;
-        public readonly bool PushOnly;
+        internal readonly int RVCount;
         internal readonly BinaryReader OpReader;
-        internal readonly HashSet<uint> BreakPoints;
+        private readonly ICrypto crypto;
+
+        public RandomAccessStack<StackItem> EvaluationStack { get; } = new RandomAccessStack<StackItem>();
+        public RandomAccessStack<StackItem> AltStack { get; } = new RandomAccessStack<StackItem>();
 
         public int InstructionPointer
         {
@@ -32,26 +33,17 @@ public byte[] ScriptHash
             get
             {
                 if (_script_hash == null)
-                    _script_hash = engine.Crypto.Hash160(Script);
+                    _script_hash = crypto.Hash160(Script);
                 return _script_hash;
             }
         }
 
-        internal ExecutionContext(ExecutionEngine engine, byte[] script, bool push_only, HashSet<uint> break_points = null)
+        internal ExecutionContext(ExecutionEngine engine, byte[] script, int rvcount)
         {
-            this.engine = engine;
             this.Script = script;
-            this.PushOnly = push_only;
+            this.RVCount = rvcount;
             this.OpReader = new BinaryReader(new MemoryStream(script, false));
-            this.BreakPoints = break_points ?? new HashSet<uint>();
-        }
-
-        public ExecutionContext Clone()
-        {
-            return new ExecutionContext(engine, Script, PushOnly, BreakPoints)
-            {
-                InstructionPointer = InstructionPointer
-            };
+            this.crypto = engine.Crypto;
         }
 
         public void Dispose()

src/neo-vm/HashComparer.cs

@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Neo.VM
+{
+    internal class HashComparer : IEqualityComparer<byte[]>
+    {
+        public bool Equals(byte[] x, byte[] y)
+        {
+            return x.SequenceEqual(y);
+        }
+
+        public int GetHashCode(byte[] obj)
+        {
+            return BitConverter.ToInt32(obj, 0);
+        }
+    }
+}

src/neo-vm/InteropService.cs

@@ -28,25 +28,25 @@ internal bool Invoke(string method, ExecutionEngine engine)
 
         private static bool GetScriptContainer(ExecutionEngine engine)
         {
-            engine.EvaluationStack.Push(StackItem.FromInterface(engine.ScriptContainer));
+            engine.CurrentContext.EvaluationStack.Push(StackItem.FromInterface(engine.ScriptContainer));
             return true;
         }
 
         private static bool GetExecutingScriptHash(ExecutionEngine engine)
         {
-            engine.EvaluationStack.Push(engine.CurrentContext.ScriptHash);
+            engine.CurrentContext.EvaluationStack.Push(engine.CurrentContext.ScriptHash);
             return true;
         }
 
         private static bool GetCallingScriptHash(ExecutionEngine engine)
         {
-            engine.EvaluationStack.Push(engine.CallingContext.ScriptHash);
+            engine.CurrentContext.EvaluationStack.Push(engine.CallingContext.ScriptHash);
             return true;
         }
 
         private static bool GetEntryScriptHash(ExecutionEngine engine)
         {
-            engine.EvaluationStack.Push(engine.EntryContext.ScriptHash);
+            engine.CurrentContext.EvaluationStack.Push(engine.EntryContext.ScriptHash);
             return true;
         }
     }

src/neo-vm/OpCode.cs

@@ -136,6 +136,15 @@ public enum OpCode : byte
         KEYS = 0xCC,
         VALUES = 0xCD,
 
+
+        // Stack isolation
+        CALL_I = 0xE0,
+        CALL_E = 0xE1,
+        CALL_ED = 0xE2,
+        CALL_ET = 0xE3,
+        CALL_EDT = 0xE4,
+
+
         // Exceptions
         THROW = 0xF0,
         THROWIFNOT = 0xF1

src/neo-vm/RandomAccessStack.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Linq;
 
 namespace Neo.VM
 {
@@ -15,6 +16,15 @@ public void Clear()
             list.Clear();
         }
 
+        public void CopyTo(RandomAccessStack<T> stack, int count = -1)
+        {
+            if (count == 0) return;
+            if (count == -1)
+                stack.list.AddRange(list);
+            else
+                stack.list.AddRange(list.Skip(list.Count - count));
+        }
+
         public IEnumerator<T> GetEnumerator()
         {
             return list.GetEnumerator();
@@ -34,7 +44,10 @@ public void Insert(int index, T item)
         public T Peek(int index = 0)
         {
             if (index >= list.Count) throw new InvalidOperationException();
-            return list[list.Count - 1 - index];
+            if (index < 0) index += list.Count;
+            if (index < 0) throw new InvalidOperationException();
+            index = list.Count - index - 1;
+            return list[index];
         }
 
         public T Pop()
@@ -50,15 +63,21 @@ public void Push(T item)
         public T Remove(int index)
         {
             if (index >= list.Count) throw new InvalidOperationException();
-            T item = list[list.Count - index - 1];
-            list.RemoveAt(list.Count - index - 1);
+            if (index < 0) index += list.Count;
+            if (index < 0) throw new InvalidOperationException();
+            index = list.Count - index - 1;
+            T item = list[index];
+            list.RemoveAt(index);
             return item;
         }
 
         public void Set(int index, T item)
         {
             if (index >= list.Count) throw new InvalidOperationException();
-            list[list.Count - index - 1] = item;
+            if (index < 0) index += list.Count;
+            if (index < 0) throw new InvalidOperationException();
+            index = list.Count - index - 1;
+            list[index] = item;
         }
     }
 }

src/neo-vm/neo-vm.csproj

@@ -4,7 +4,7 @@
     <Copyright>2016-2017 The Neo Project</Copyright>
     <AssemblyTitle>Neo.VM</AssemblyTitle>
     <Description>Neo.VM</Description>
-    <Version>2.2.1</Version>
+    <Version>2.3.0</Version>
     <Authors>The Neo Project</Authors>
     <TargetFrameworks>netstandard1.6;net461</TargetFrameworks>
     <AssemblyName>Neo.VM</AssemblyName>