Feature: return to stack

sandbox/Benchmark/AddBenchmark.cs

@@ -22,10 +22,11 @@ public void Setup()
         core.Setup("add.lua");
         core.LuaCSharpState.OpenStandardLibraries();
 
-        core.LuaCSharpState.Environment["add"] = new LuaFunction("add", (context, buffer, ct) =>
+        core.LuaCSharpState.Environment["add"] = new LuaFunction("add", (context, ct) =>
         {
-            buffer.Span[0] = context.GetArgument<double>(0) + context.GetArgument<double>(1);
-            return new(1);
+            var a = context.GetArgument<double>(0);
+            var b = context.GetArgument<double>(1);
+            return new(context.Return(a + b));
         });
         core.MoonSharpState.Globals["add"] = (Func<double, double, double>)Add;
         core.NLuaState.RegisterFunction("add", typeof(AddBenchmark).GetMethod(nameof(Add), BindingFlags.Static | BindingFlags.Public));

sandbox/Benchmark/InterpreterSteps.cs

@@ -92,6 +92,8 @@ public Chunk Compile()
     [Benchmark]
     public async ValueTask RunAsync()
     {
-        await state.RunAsync(chunk, results);
+        using (await state.RunAsync(chunk))
+        {
+        }
     }
 }

sandbox/ConsoleApp1/Program.cs

@@ -1,3 +1,4 @@
+using System.Runtime.CompilerServices;
 using Lua.CodeAnalysis.Syntax;
 using Lua.CodeAnalysis.Compilation;
 using Lua.Runtime;
@@ -11,7 +12,7 @@
 
 try
 {
-    var source = File.ReadAllText("test.lua");
+    var source = File.ReadAllText(GetAbsolutePath("test.lua"));
 
     var syntaxTree = LuaSyntaxTree.Parse(source, "test.lua");
 
@@ -26,12 +27,11 @@
 
     Console.WriteLine("Output " + new string('-', 50));
 
-    var results = new LuaValue[64];
-    var resultCount = await state.RunAsync(chunk, results);
+    using var results = await state.RunAsync(chunk);
 
     Console.WriteLine("Result " + new string('-', 50));
 
-    for (int i = 0; i < resultCount; i++)
+    for (int i = 0; i < results.Count; i++)
     {
         Console.WriteLine(results[i]);
     }
@@ -41,6 +41,19 @@
 catch (Exception ex)
 {
     Console.WriteLine(ex);
+    if (ex is LuaRuntimeException luaRuntimeException)
+    {
+        Console.WriteLine(luaRuntimeException.LuaTraceback);
+        if (ex is { InnerException: not null } luaEx)
+        {
+            Console.WriteLine(luaEx.InnerException);
+        }
+    }
+}
+
+static string GetAbsolutePath(string relativePath, [CallerFilePath] string callerFilePath = "")
+{
+    return Path.Combine(Path.GetDirectoryName(callerFilePath)!, relativePath);
 }
 
 static void DebugChunk(Chunk chunk, int id)
@@ -56,14 +69,24 @@ static void DebugChunk(Chunk chunk, int id)
         index++;
     }
 
-    Console.WriteLine("Constants " + new string('-', 50)); index = 0;
+    Console.WriteLine("Locals " + new string('-', 50));
+    index = 0;
+    foreach (var local in chunk.Locals.ToArray())
+    {
+        Console.WriteLine($"[{index}]\t{local.Index}\t{local.Name}\t{local.StartPc}\t{local.EndPc}");
+        index++;
+    }
+
+    Console.WriteLine("Constants " + new string('-', 50));
+    index = 0;
     foreach (var constant in chunk.Constants.ToArray())
     {
         Console.WriteLine($"[{index}]\t{constant}");
         index++;
     }
 
-    Console.WriteLine("UpValues " + new string('-', 50)); index = 0;
+    Console.WriteLine("UpValues " + new string('-', 50));
+    index = 0;
     foreach (var upValue in chunk.UpValues.ToArray())
     {
         Console.WriteLine($"[{index}]\t{upValue.Name}\t{(upValue.IsInRegister ? 1 : 0)}\t{upValue.Index}");

src/Lua.SourceGenerator/LuaObjectGenerator.Emit.cs

@@ -201,7 +201,7 @@ static bool ValidateMembers(TypeMetadata typeMetadata, Compilation compilation,
 
     static bool TryEmitIndexMetamethod(TypeMetadata typeMetadata, CodeBuilder builder, in SourceProductionContext context)
     {
-        builder.AppendLine(@"static readonly global::Lua.LuaFunction __metamethod_index = new global::Lua.LuaFunction(""index"", (context, buffer, ct) =>");
+        builder.AppendLine(@"static readonly global::Lua.LuaFunction __metamethod_index = new global::Lua.LuaFunction(""index"", (context, ct) =>");
 
         using (builder.BeginBlockScope())
         {
@@ -233,8 +233,7 @@ static bool TryEmitIndexMetamethod(TypeMetadata typeMetadata, CodeBuilder builde
             }
             builder.AppendLine(";");
 
-            builder.AppendLine("buffer.Span[0] = result;");
-            builder.AppendLine("return new(1);");
+            builder.AppendLine( "return new global::System.Threading.Tasks.ValueTask<int>(context.Return(result));");
         }
 
         builder.AppendLine(");");
@@ -244,7 +243,7 @@ static bool TryEmitIndexMetamethod(TypeMetadata typeMetadata, CodeBuilder builde
 
     static bool TryEmitNewIndexMetamethod(TypeMetadata typeMetadata, CodeBuilder builder, in SourceProductionContext context)
     {
-        builder.AppendLine(@"static readonly global::Lua.LuaFunction __metamethod_newindex = new global::Lua.LuaFunction(""newindex"", (context, buffer, ct) =>");
+        builder.AppendLine(@"static readonly global::Lua.LuaFunction __metamethod_newindex = new global::Lua.LuaFunction(""newindex"", (context, ct) =>");
 
         using (builder.BeginBlockScope())
         {
@@ -295,8 +294,7 @@ static bool TryEmitNewIndexMetamethod(TypeMetadata typeMetadata, CodeBuilder bui
                     builder.AppendLine(@$"throw new global::Lua.LuaRuntimeException(context.State.GetTraceback(), $""'{{key}}' not found."");");
                 }
             }
-
-            builder.AppendLine("return new(0);");
+            builder.AppendLine( "return new global::System.Threading.Tasks.ValueTask<int>(context.Return());");
         }
 
         builder.AppendLine(");");
@@ -348,7 +346,7 @@ static bool TryEmitMethods(TypeMetadata typeMetadata, CodeBuilder builder, Symbo
 
     static void EmitMethodFunction(string functionName, string chunkName, TypeMetadata typeMetadata, MethodMetadata methodMetadata, CodeBuilder builder, SymbolReferences references)
     {
-        builder.AppendLine($@"static readonly global::Lua.LuaFunction {functionName} = new global::Lua.LuaFunction(""{chunkName}"", {(methodMetadata.IsAsync ? "async" : "")} (context, buffer, ct) =>");
+        builder.AppendLine($@"static readonly global::Lua.LuaFunction {functionName} = new global::Lua.LuaFunction(""{chunkName}"", {(methodMetadata.IsAsync ? "async" : "")} (context, ct) =>");
 
         using (builder.BeginBlockScope())
         {
@@ -413,23 +411,28 @@ static void EmitMethodFunction(string functionName, string chunkName, TypeMetada
                 builder.Append(string.Join(",", Enumerable.Range(1, index - 1).Select(x => $"arg{x}")), false);
                 builder.AppendLine(");", false);
             }
-
+
+            builder.Append("return ");
             if (methodMetadata.HasReturnValue)
             {
                 if (SymbolEqualityComparer.Default.Equals(methodMetadata.Symbol.ReturnType, references.LuaValue))
                 {
-                    builder.AppendLine("buffer.Span[0] = result;");
+
+                    builder.AppendLine(methodMetadata.IsAsync ?
+                        "context.Return(result));" :
+                        "new global::System.Threading.Tasks.ValueTask<int>(context.Return(result));");
                 }
                 else
                 {
-                    builder.AppendLine("buffer.Span[0] = new global::Lua.LuaValue(result);");
+                     builder.AppendLine(methodMetadata.IsAsync ?
+                        "context.Return(new global::Lua.LuaValue(result))));" :
+                        "new global::System.Threading.Tasks.ValueTask<int>(context.Return(new global::Lua.LuaValue(result)));");
                 }
 
-                builder.AppendLine($"return {(methodMetadata.IsAsync ? "1" : "new(1)")};");
             }
             else
             {
-                builder.AppendLine($"return {(methodMetadata.IsAsync ? "0" : "new(0)")};");
+                builder.AppendLine(methodMetadata.IsAsync ? "context.Return();" : "new global::System.Threading.Tasks.ValueTask<int>(context.Return());");
             }
         }
         builder.AppendLine(");");

src/Lua/CodeAnalysis/Compilation/Descriptions.cs

@@ -6,6 +6,7 @@ namespace Lua.CodeAnalysis.Compilation
     public readonly record struct LocalVariableDescription
     {
         public required byte RegisterIndex { get; init; }
+        public required int StartPc { get; init; }
     }
 
     public readonly record struct FunctionDescription

src/Lua/CodeAnalysis/Compilation/FunctionCompilationContext.cs

@@ -60,6 +60,7 @@ internal static FunctionCompilationContext Create(ScopeCompilationContext? paren
 
     // upvalues
     FastListCore<UpValueInfo> upvalues;
+    FastListCore<LocalValueInfo> localVariables;
 
     // loop
     FastListCore<BreakDescription> breakQueue;
@@ -90,6 +91,16 @@ internal static FunctionCompilationContext Create(ScopeCompilationContext? paren
     /// </summary>
     public bool HasVariableArguments { get; set; }
 
+    /// <summary>
+    /// Line number where the function is defined
+    /// </summary>
+    public int LineDefined { get; set; }
+
+    /// <summary>
+    /// Last line number where the function is defined
+    /// </summary>
+    public int LastLineDefined { get; set; }
+
     /// <summary>
     /// Parent scope context
     /// </summary>
@@ -127,6 +138,7 @@ public void PushOrMergeInstruction(int lastLocal, in Instruction instruction, in
             instructionPositions.Add(position);
             return;
         }
+
         ref var lastInstruction = ref instructions.AsSpan()[^1];
         var opcode = instruction.OpCode;
         switch (opcode)
@@ -156,6 +168,7 @@ public void PushOrMergeInstruction(int lastLocal, in Instruction instruction, in
                             }
                     }
                 }
+
                 break;
             case OpCode.GetTable:
                 {
@@ -169,8 +182,8 @@ public void PushOrMergeInstruction(int lastLocal, in Instruction instruction, in
                             incrementStackPosition = false;
                             return;
                         }
-
                     }
+
                     break;
                 }
             case OpCode.SetTable:
@@ -197,6 +210,7 @@ public void PushOrMergeInstruction(int lastLocal, in Instruction instruction, in
                                     return;
                                 }
                             }
+
                             lastInstruction = Instruction.SetTable((byte)(lastB), instruction.B, instruction.C);
                             instructionPositions[^1] = position;
                             incrementStackPosition = false;
@@ -217,7 +231,6 @@ public void PushOrMergeInstruction(int lastLocal, in Instruction instruction, in
                         var last2OpCode = last2Instruction.OpCode;
                         if (last2OpCode is OpCode.LoadK or OpCode.Move)
                         {
-
                             var last2A = last2Instruction.A;
                             if (last2A != lastLocal && instruction.C == last2A)
                             {
@@ -231,18 +244,21 @@ public void PushOrMergeInstruction(int lastLocal, in Instruction instruction, in
                             }
                         }
                     }
+
                     break;
                 }
             case OpCode.Unm:
             case OpCode.Not:
             case OpCode.Len:
                 if (lastInstruction.OpCode == OpCode.Move && lastLocal != lastInstruction.A && lastInstruction.A == instruction.B)
                 {
-                    lastInstruction = instruction with { B = lastInstruction.B }; ;
+                    lastInstruction = instruction with { B = lastInstruction.B };
+                    ;
                     instructionPositions[^1] = position;
                     incrementStackPosition = false;
                     return;
                 }
+
                 break;
             case OpCode.Return:
                 if (lastInstruction.OpCode == OpCode.Move && instruction.B == 2 && lastInstruction.B < 256)
@@ -252,6 +268,7 @@ public void PushOrMergeInstruction(int lastLocal, in Instruction instruction, in
                     incrementStackPosition = false;
                     return;
                 }
+
                 break;
         }
 
@@ -302,6 +319,17 @@ public bool TryGetFunctionProto(ReadOnlyMemory<char> name, [NotNullWhen(true)] o
         }
     }
 
+    public void AddLocalVariable(ReadOnlyMemory<char> name, LocalVariableDescription description)
+    {
+        localVariables.Add(new LocalValueInfo()
+        {
+            Name = name,
+            Index = description.RegisterIndex,
+            StartPc = description.StartPc,
+            EndPc = Instructions.Length,
+        });
+    }
+
     public void AddUpValue(UpValueInfo upValue)
     {
         upvalues.Add(upValue);
@@ -378,6 +406,7 @@ public void ResolveAllBreaks(byte startPosition, int endPosition, ScopeCompilati
             {
                 instruction.A = startPosition;
             }
+
             instruction.SBx = endPosition - description.Index;
         }
 
@@ -409,18 +438,24 @@ public Chunk ToChunk()
     {
         // add return
         instructions.Add(Instruction.Return(0, 1));
-        instructionPositions.Add(instructionPositions.Length == 0 ? default : instructionPositions[^1]);
-
+        instructionPositions.Add( new (LastLineDefined, 0));
+        Scope.RegisterLocalsToFunction();
+        var locals = localVariables.AsSpan().ToArray();
+        Array.Sort(locals, (x, y) => x.Index.CompareTo(y.Index));
         var chunk = new Chunk()
         {
             Name = ChunkName ?? "chunk",
             Instructions = instructions.AsSpan().ToArray(),
             SourcePositions = instructionPositions.AsSpan().ToArray(),
             Constants = constants.AsSpan().ToArray(),
             UpValues = upvalues.AsSpan().ToArray(),
+            Locals = locals,
             Functions = functions.AsSpan().ToArray(),
             ParameterCount = ParameterCount,
+            HasVariableArguments = HasVariableArguments,
             MaxStackPosition = MaxStackPosition,
+            LineDefined = LineDefined,
+            LastLineDefined = LastLineDefined,
         };
 
         foreach (var function in functions.AsSpan())
@@ -442,6 +477,7 @@ public void Reset()
         constantIndexMap.Clear();
         constants.Clear();
         upvalues.Clear();
+        localVariables.Clear();
         functionMap.Clear();
         functions.Clear();
         breakQueue.Clear();