Fixed issues with operand replacing, and branch instructions.

Torch/Managers/PatchManager/MSIL/MsilInstruction.cs

@@ -4,6 +4,7 @@
 using System.Reflection.Emit;
 using System.Text;
 using Torch.Managers.PatchManager.Transpile;
+using Torch.Utils;
 using Label = System.Windows.Controls.Label;
 
 namespace Torch.Managers.PatchManager.MSIL
@@ -13,8 +14,6 @@ namespace Torch.Managers.PatchManager.MSIL
     /// </summary>
     public class MsilInstruction
     {
-        private MsilOperand _operandBacking;
-
         /// <summary>
         ///     Creates a new instruction with the given opcode.
         /// </summary>
@@ -97,16 +96,7 @@ public MsilInstruction(OpCode opcode)
         /// <summary>
         ///     The operand for this instruction, or null.
         /// </summary>
-        public MsilOperand Operand
-        {
-            get => _operandBacking;
-            set
-            {
-                if (_operandBacking != null && value.GetType() != _operandBacking.GetType())
-                    throw new ArgumentException($"Operand for {OpCode.Name} must be {_operandBacking.GetType().Name}");
-                _operandBacking = value;
-            }
-        }
+        public MsilOperand Operand { get; }
 
         /// <summary>
         ///     Labels pointing to this instruction.
@@ -128,11 +118,12 @@ public MsilInstruction InlineValue<T>(T o)
         /// <summary>
         /// Makes a copy of the instruction with a new opcode.
         /// </summary>
-        /// <param name="code">The new opcode</param>
+        /// <param name="newOpcode">The new opcode</param>
         /// <returns>The copy</returns>
-        public MsilInstruction CopyWith(OpCode code)
+        public MsilInstruction CopyWith(OpCode newOpcode)
         {
-            var result = new MsilInstruction(code) { Operand = this.Operand };
+            var result = new MsilInstruction(newOpcode);
+            Operand?.CopyTo(result.Operand);
             foreach (MsilLabel x in Labels)
                 result.Labels.Add(x);
             return result;
@@ -172,5 +163,28 @@ public override string ToString()
             sb.Append(OpCode.Name).Append("\t").Append(Operand);
             return sb.ToString();
         }
+
+
+
+#pragma warning disable 169
+        [ReflectedMethod(Name = "StackChange")]
+        private static Func<OpCode, int> _stackChange;
+#pragma warning restore 169
+
+        public int StackChange()
+        {
+            int num = _stackChange.Invoke(OpCode);
+            if ((OpCode == OpCodes.Call || OpCode == OpCodes.Callvirt || OpCode == OpCodes.Newobj) &&
+                Operand is MsilOperandInline<MethodBase> inline)
+            {
+                MethodBase op = inline.Value;
+                if (op is MethodInfo mi && mi.ReturnType != typeof(void))
+                    num++;
+                num -= op.GetParameters().Length;
+                if (!op.IsStatic && OpCode != OpCodes.Newobj)
+                    num--;
+            }
+            return num;
+        }
     }
 }

Torch/Managers/PatchManager/MSIL/MsilOperand.cs

@@ -18,6 +18,8 @@ protected MsilOperand(MsilInstruction instruction)
         /// </summary>
         public MsilInstruction Instruction { get; }
 
+        internal abstract void CopyTo(MsilOperand operand);
+
         internal abstract void Read(MethodContext context, BinaryReader reader);
 
         internal abstract void Emit(LoggingIlGenerator generator);

Torch/Managers/PatchManager/MSIL/MsilOperandBrTarget.cs

@@ -1,4 +1,5 @@
-using System.IO;
+using System;
+using System.IO;
 using System.Reflection.Emit;
 using Torch.Managers.PatchManager.Transpile;
 
@@ -22,15 +23,23 @@ internal override void Read(MethodContext context, BinaryReader reader)
         {
             int val = Instruction.OpCode.OperandType == OperandType.InlineBrTarget
                 ? reader.ReadInt32()
-                : reader.ReadByte();
-            Target = context.LabelAt((int) reader.BaseStream.Position + val);
+                : reader.ReadSByte();
+            Target = context.LabelAt((int)reader.BaseStream.Position + val);
         }
 
         internal override void Emit(LoggingIlGenerator generator)
         {
             generator.Emit(Instruction.OpCode, Target.LabelFor(generator));
         }
 
+        internal override void CopyTo(MsilOperand operand)
+        {
+            var lt = operand as MsilOperandBrTarget;
+            if (lt == null)
+                throw new ArgumentException($"Target {operand?.GetType().Name} must be of same type {GetType().Name}", nameof(operand));
+            lt.Target = Target;
+        }
+
         /// <inheritdoc />
         public override string ToString()
         {

Torch/Managers/PatchManager/MSIL/MsilOperandInline.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Diagnostics;
 using System.IO;
+using System.Linq;
 using System.Reflection;
 using System.Reflection.Emit;
 using Torch.Managers.PatchManager.Transpile;
@@ -22,6 +23,15 @@ internal MsilOperandInline(MsilInstruction instruction) : base(instruction)
         /// </summary>
         public T Value { get; set; }
 
+        internal override void CopyTo(MsilOperand operand)
+        {
+            var lt = operand as MsilOperandInline<T>;
+            if (lt == null)
+                throw new ArgumentException($"Target {operand?.GetType().Name} must be of same type {GetType().Name}", nameof(operand));
+            lt.Value = Value;
+            ;
+        }
+
         /// <inheritdoc />
         public override string ToString()
         {
@@ -66,7 +76,7 @@ internal MsilOperandInt8(MsilInstruction instruction) : base(instruction)
             internal override void Read(MethodContext context, BinaryReader reader)
             {
                 Value =
-                    (sbyte) reader.ReadByte();
+                    (sbyte)reader.ReadByte();
             }
 
             internal override void Emit(LoggingIlGenerator generator)
@@ -209,16 +219,19 @@ internal MsilOperandParameter(MsilInstruction instruction) : base(instruction)
 
             internal override void Read(MethodContext context, BinaryReader reader)
             {
-                Value =
-                    context.Method.GetParameters()[
-                        Instruction.OpCode.OperandType == OperandType.ShortInlineVar
-                            ? reader.ReadByte()
-                            : reader.ReadUInt16()];
+                int paramID =
+                    Instruction.OpCode.OperandType == OperandType.ShortInlineVar
+                        ? reader.ReadByte()
+                        : reader.ReadUInt16();
+                if (paramID == 0 && !context.Method.IsStatic)
+                    throw new ArgumentException("Haven't figured out how to ldarg with the \"this\" argument");
+                Value = context.Method.GetParameters()[paramID - (context.Method.IsStatic ? 0 : 1)];
             }
 
             internal override void Emit(LoggingIlGenerator generator)
             {
-                generator.Emit(Instruction.OpCode, Value.Position);
+                var methodInfo = Value.Member as MethodBase;
+                generator.Emit(Instruction.OpCode, Value.Position + (methodInfo != null && methodInfo.IsStatic ? 0 : 1));
             }
         }
 

Torch/Managers/PatchManager/MSIL/MsilOperandSwitch.cs

@@ -1,4 +1,5 @@
-using System.IO;
+using System;
+using System.IO;
 using System.Linq;
 using System.Reflection.Emit;
 using Torch.Managers.PatchManager.Transpile;
@@ -19,6 +20,20 @@ internal MsilOperandSwitch(MsilInstruction instruction) : base(instruction)
         /// </summary>
         public MsilLabel[] Labels { get; set; }
 
+
+        internal override void CopyTo(MsilOperand operand)
+        {
+            var lt = operand as MsilOperandSwitch;
+            if (lt == null)
+                throw new ArgumentException($"Target {operand?.GetType().Name} must be of same type {GetType().Name}", nameof(operand));
+            if (Labels == null)
+                lt.Labels = null;
+            else
+            {
+                lt.Labels = new MsilLabel[Labels.Length];
+                Array.Copy(Labels, lt.Labels, Labels.Length);
+            }
+        }
         internal override void Read(MethodContext context, BinaryReader reader)
         {
             int length = reader.ReadInt32();

Torch/Managers/PatchManager/Transpile/LoggingILGenerator.cs

@@ -52,7 +52,7 @@ public void Emit(OpCode op)
         /// <inheritdoc cref="ILGenerator.Emit(OpCode, LocalBuilder)"/>
         public void Emit(OpCode op, LocalBuilder arg)
         {
-            _log?.Trace($"Emit\t{op,_opcodePadding} L:{arg.LocalIndex} {arg.LocalType}");
+            _log?.Trace($"Emit\t{op,_opcodePadding} Local:{arg.LocalIndex}/{arg.LocalType}");
             Backing.Emit(op, arg);
         }
 

Torch/Managers/PatchManager/Transpile/MethodContext.cs

@@ -7,6 +7,7 @@
 using System.Reflection.Emit;
 using NLog;
 using Torch.Managers.PatchManager.MSIL;
+using Torch.Utils;
 
 namespace Torch.Managers.PatchManager.Transpile
 {
@@ -52,20 +53,19 @@ private void ReadInstructions()
             using (var reader = new BinaryReader(memory))
                 while (memory.Length > memory.Position)
                 {
-                    var count = 1;
+                    var opcodeOffset = (int) memory.Position;
                     var instructionValue = (short)memory.ReadByte();
                     if (Prefixes.Contains(instructionValue))
                     {
                         instructionValue = (short)((instructionValue << 8) | memory.ReadByte());
-                        count++;
                     }
                     if (!OpCodeLookup.TryGetValue(instructionValue, out OpCode opcode))
                         throw new Exception($"Unknown opcode {instructionValue:X}");
-                    if (opcode.Size != count)
-                        throw new Exception($"Opcode said it was {opcode.Size} but we read {count}");
+                    if (opcode.Size != memory.Position - opcodeOffset)
+                        throw new Exception($"Opcode said it was {opcode.Size} but we read {memory.Position - opcodeOffset}");
                     var instruction = new MsilInstruction(opcode)
                     {
-                        Offset = (int)memory.Position
+                        Offset = opcodeOffset
                     };
                     _instructions.Add(instruction);
                     instruction.Operand?.Read(this, reader);
@@ -76,22 +76,74 @@ private void ResolveLabels()
         {
             foreach (var label in Labels)
             {
-                int min = 0, max = _instructions.Count - 1;
-                while (min <= max)
+                int min = 0, max = _instructions.Count;
+                while (min != max)
                 {
-                    var mid = min + ((max - min) / 2);
-                    if (label.Key < _instructions[mid].Offset)
-                        max = mid - 1;
-                    else
+                    int mid = (min + max) / 2;
+                    if (_instructions[mid].Offset < label.Key)
                         min = mid + 1;
+                    else
+                        max = mid;
                 }
+#if DEBUG
+                if (min >= _instructions.Count || min < 0)
+                {
+                    _log.Trace(
+                        $"Want offset {label.Key} for {label.Value}, instruction offsets at\n {string.Join("\n", _instructions.Select(x => $"IL_{x.Offset:X4} {x}"))}");
+                }
+                MsilInstruction prevInsn = min > 0 ? _instructions[min - 1] : null;
+                if ((prevInsn == null || prevInsn.Offset >= label.Key) ||
+                    _instructions[min].Offset < label.Key)
+                    _log.Error($"Label {label.Value} wanted {label.Key} but instruction is at {_instructions[min].Offset}.  Previous instruction is at {prevInsn?.Offset ?? -1}");
+#endif
                 _instructions[min]?.Labels?.Add(label.Value);
             }
         }
 
+
+        [Conditional("DEBUG")]
+        public void CheckIntegrity()
+        {
+            var entryStackCount = new Dictionary<MsilLabel, Dictionary<MsilInstruction, int>>();
+            var currentStackSize = 0;
+            foreach (MsilInstruction insn in _instructions)
+            {
+                // I don't want to deal with this, so I won't
+                if (insn.OpCode == OpCodes.Br || insn.OpCode == OpCodes.Br_S || insn.OpCode == OpCodes.Jmp ||
+                    insn.OpCode == OpCodes.Leave || insn.OpCode == OpCodes.Leave_S)
+                    break;
+                foreach (MsilLabel label in insn.Labels)
+                    if (entryStackCount.TryGetValue(label, out Dictionary<MsilInstruction, int> dict))
+                        dict.Add(insn, currentStackSize);
+                    else
+                        (entryStackCount[label] = new Dictionary<MsilInstruction, int>()).Add(insn, currentStackSize);
+
+                currentStackSize += insn.StackChange();
+
+                if (insn.Operand is MsilOperandBrTarget br)
+                    if (entryStackCount.TryGetValue(br.Target, out Dictionary<MsilInstruction, int> dict))
+                        dict.Add(insn, currentStackSize);
+                    else
+                        (entryStackCount[br.Target] = new Dictionary<MsilInstruction, int>()).Add(insn, currentStackSize);
+            }
+            foreach (KeyValuePair<MsilLabel, Dictionary<MsilInstruction, int>> label in entryStackCount)
+            {
+                if (label.Value.Values.Aggregate(new HashSet<int>(), (a, b) =>
+                {
+                    a.Add(b);
+                    return a;
+                }).Count > 1)
+                {
+                    _log.Warn($"Label {label.Key} has multiple entry stack counts");
+                    foreach (KeyValuePair<MsilInstruction, int> kv in label.Value)
+                        _log.Warn($"{kv.Key.Offset:X4} {kv.Key} => {kv.Value}");
+                }
+            }
+        }
+
         public string ToHumanMsil()
         {
-            return string.Join("\n", _instructions.Select(x => $"IL_{x.Offset:X4}: {x}"));
+            return string.Join("\n", _instructions.Select(x => $"IL_{x.Offset:X4}: {x.StackChange()} {x}"));
         }
 
         private static readonly Dictionary<short, OpCode> OpCodeLookup;

Torch/Managers/PatchManager/Transpile/MethodTranspiler.cs

@@ -9,16 +9,17 @@ namespace Torch.Managers.PatchManager.Transpile
 {
     internal class MethodTranspiler
     {
-        private static readonly Logger _log = LogManager.GetCurrentClassLogger();
+        public static readonly Logger _log = LogManager.GetCurrentClassLogger();
 
         internal static void Transpile(MethodBase baseMethod, IEnumerable<MethodInfo> transpilers, LoggingIlGenerator output, Label? retLabel)
         {
             var context = new MethodContext(baseMethod);
             context.Read();
+            context.CheckIntegrity();
             _log.Trace("Input Method:");
             _log.Trace(context.ToHumanMsil);
 
-            var methodContent = (IEnumerable<MsilInstruction>) context.Instructions;
+            var methodContent = (IEnumerable<MsilInstruction>)context.Instructions;
             foreach (var transpiler in transpilers)
                 methodContent = (IEnumerable<MsilInstruction>)transpiler.Invoke(null, new object[] { methodContent });
             methodContent = FixBranchAndReturn(methodContent, retLabel);
@@ -35,15 +36,17 @@ private static IEnumerable<MsilInstruction> FixBranchAndReturn(IEnumerable<MsilI
                     MsilInstruction j = new MsilInstruction(OpCodes.Br).InlineTarget(new MsilLabel(retTarget.Value));
                     foreach (MsilLabel l in i.Labels)
                         j.Labels.Add(l);
+                    _log.Trace($"Replacing {i} with {j}");
                     yield return j;
-                    continue;
                 }
-                if (_opcodeReplaceRule.TryGetValue(i.OpCode, out OpCode replaceOpcode))
+                else if (_opcodeReplaceRule.TryGetValue(i.OpCode, out OpCode replaceOpcode))
                 {
-                    yield return i.CopyWith(replaceOpcode);
-                    continue;
+                    var result = i.CopyWith(replaceOpcode);
+                    _log.Trace($"Replacing {i} with {result}");
+                    yield return result;
                 }
-                yield return i;
+                else
+                    yield return i;
             }
         }
 
@@ -57,7 +60,7 @@ static MethodTranspiler()
                 if (opcode.OperandType == OperandType.ShortInlineBrTarget &&
                     opcode.Name.EndsWith(".s", StringComparison.OrdinalIgnoreCase))
                 {
-                    var other = (OpCode?) typeof(OpCodes).GetField(field.Name.Substring(0, field.Name.Length - 2),
+                    var other = (OpCode?)typeof(OpCodes).GetField(field.Name.Substring(0, field.Name.Length - 2),
                         BindingFlags.Static | BindingFlags.Public)?.GetValue(null);
                     if (other.HasValue && other.Value.OperandType == OperandType.InlineBrTarget)
                         _opcodeReplaceRule.Add(opcode, other.Value);