c# 10 and assembly unloading for in-game scripts

Torch/Managers/ScriptCompilationManager.cs

@@ -0,0 +1,231 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.IO;
+using System.Linq;
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.Loader;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Emit;
+using Sandbox.Game.Entities.Blocks;
+using Sandbox.Game.EntityComponents;
+using Sandbox.ModAPI;
+using Sandbox.ModAPI.Ingame;
+using Torch.API;
+using Torch.Utils;
+using VRage;
+using VRage.ModAPI;
+using VRage.Scripting;
+
+namespace Torch.Managers;
+
+public class ScriptCompilationManager : Manager
+{
+    [ReflectedSetter(Name = "m_terminationReason")]
+    private static Action<MyProgrammableBlock, MyProgrammableBlock.ScriptTerminationReason> TerminationReasonSetter = null!;
+
+    [ReflectedGetter(Name = "ScriptComponent")]
+    private static Func<MyProgrammableBlock, MyIngameScriptComponent> ScriptComponentGetter = null!;
+
+    [ReflectedMethod]
+    private static Action<MyProgrammableBlock, string> SetDetailedInfo = null!;
+
+    [ReflectedSetter(Name = "m_instance")]
+    private static Action<MyProgrammableBlock, IMyGridProgram> InstanceSetter = null!;
+
+    [ReflectedSetter(Name = "m_assembly")]
+    private static Action<MyProgrammableBlock, Assembly> AssemblySetter = null!;
+
+    [ReflectedMethod]
+    private static Func<MyProgrammableBlock, Assembly, IEnumerable<string>, string, bool> CreateInstance = null!;
+
+    [ReflectedGetter(Name = "m_compilerErrors")]
+    private static Func<MyProgrammableBlock, List<string>> CompilerErrorsGetter = null!;
+
+    [ReflectedGetter(Name = "m_modApiWhitelistDiagnosticAnalyzer")]
+    private static Func<MyScriptCompiler, DiagnosticAnalyzer> ModWhitelistAnalyzer = null!;
+
+    [ReflectedGetter(Name = "m_ingameWhitelistDiagnosticAnalyzer")]
+    private static Func<MyScriptCompiler, DiagnosticAnalyzer> ScriptWhitelistAnalyzer = null!;
+
+    [ReflectedMethod]
+    private static Func<MyScriptCompiler, CSharpCompilation, SyntaxTree, int, SyntaxTree> InjectMod = null!;
+
+    [ReflectedMethod]
+    private static Func<MyScriptCompiler, CSharpCompilation, SyntaxTree, SyntaxTree> InjectInstructionCounter = null!;
+
+    [ReflectedMethod]
+    private static Func<MyScriptCompiler, CompilationWithAnalyzers, EmitResult, List<Message>, bool, Task<bool>> EmitDiagnostics = null!;
+
+    [ReflectedMethod]
+    private static Func<MyScriptCompiler, MyApiTarget, string, IList<SyntaxTree>, string, Task> WriteDiagnostics = null!;
+
+    [ReflectedMethod(Name = "WriteDiagnostics")]
+    private static Func<MyScriptCompiler, MyApiTarget, string, IEnumerable<Message>, bool, Task> WriteDiagnostics2 = null!;
+    
+    [ReflectedGetter(Name = "m_metadataReferences")]
+    private static Func<MyScriptCompiler, List<MetadataReference>> MetadataReferencesGetter = null!;
+
+    private readonly ConditionalWeakTable<MyProgrammableBlock, AssemblyLoadContext> _contexts = new();
+
+    public ScriptCompilationManager(ITorchBase torchInstance) : base(torchInstance)
+    {
+    }
+
+    public async void CompileAsync(MyProgrammableBlock block, string program, string storage, bool instantiate)
+    {
+        TerminationReasonSetter(block, MyProgrammableBlock.ScriptTerminationReason.None);
+
+        var component = ScriptComponentGetter(block);
+        component.NextUpdate = UpdateType.None;
+        component.NeedsUpdate = MyEntityUpdateEnum.NONE;
+
+        try
+        {
+            if (_contexts.TryGetValue(block, out var context))
+            {
+                InstanceSetter(block, null);
+                AssemblySetter(block, null);
+                context!.Unload();
+            }
+
+            _contexts.AddOrUpdate(block, context = new AssemblyLoadContext(null, true));
+
+            var messages = new List<Message>();
+            var assembly = await CompileAsync(context, MyApiTarget.Ingame,
+                                              $"pb_{block.EntityId}_{Random.Shared.NextInt64()}",
+                                              new[]
+                                              {
+                                                  MyVRage.Platform.Scripting.GetIngameScript(
+                                                      program, "Program", nameof(MyGridProgram))
+                                              }, messages, $"PB: {block.DisplayName} ({block.EntityId})");
+            AssemblySetter(block, assembly);
+            var errors = CompilerErrorsGetter(block);
+
+            errors.Clear();
+            errors.AddRange(messages.Select(b => b.Text));
+
+            if (instantiate)
+                await Torch.InvokeAsync(() => CreateInstance(block, assembly, errors, storage));
+        }
+        catch (Exception e)
+        {
+            await Torch.InvokeAsync(() => SetDetailedInfo(block, e.ToString()));
+            throw;
+        }
+    }
+
+    public async Task<Assembly> CompileAsync(AssemblyLoadContext context, MyApiTarget target, string assemblyName, IEnumerable<Script> scripts, List<Message> messages, string friendlyName, bool enableDebugInformation = false)
+    {
+        friendlyName ??= "<No Name>";
+        Func<CSharpCompilation, SyntaxTree, SyntaxTree> syntaxTreeInjector;
+        DiagnosticAnalyzer whitelistAnalyzer;
+        switch (target)
+        {
+            case MyApiTarget.None:
+                whitelistAnalyzer = null;
+                syntaxTreeInjector = null;
+                break;
+            case MyApiTarget.Mod:
+            {
+                var modId = MyModWatchdog.AllocateModId(friendlyName);
+                whitelistAnalyzer = ModWhitelistAnalyzer(MyScriptCompiler.Static);
+                syntaxTreeInjector = (c, st) => InjectMod(MyScriptCompiler.Static, c, st, modId);
+                break;
+            }
+            case MyApiTarget.Ingame:
+                syntaxTreeInjector = (c, t) => InjectInstructionCounter(MyScriptCompiler.Static, c, t);
+                whitelistAnalyzer = ScriptWhitelistAnalyzer(MyScriptCompiler.Static);
+                break;
+            default:
+                throw new ArgumentOutOfRangeException(nameof(target), target, "Invalid compilation target");
+        }
+        var compilation = CreateCompilation(assemblyName, scripts);
+        
+        await WriteDiagnostics(MyScriptCompiler.Static, target, assemblyName, compilation.SyntaxTrees, null).ConfigureAwait(false);
+        var injectionFailed = false;
+        var compilationWithoutInjection = compilation;
+        if (syntaxTreeInjector != null)
+        {
+            SyntaxTree[] newSyntaxTrees = null;
+            try
+            {
+                var syntaxTrees = compilation.SyntaxTrees;
+                if (syntaxTrees.Length == 1)
+                {
+                    newSyntaxTrees = new[] { syntaxTreeInjector(compilation, syntaxTrees[0]) };
+                }
+                else
+                {
+                    newSyntaxTrees = await Task
+                                           .WhenAll(syntaxTrees.Select(
+                                                        x => Task.Run(() => syntaxTreeInjector(compilation, x))))
+                                           .ConfigureAwait(false);
+                }
+            }
+            catch
+            {
+                injectionFailed = true;
+            }
+            if (!injectionFailed)
+            {
+                await WriteDiagnostics(MyScriptCompiler.Static, target, assemblyName, newSyntaxTrees, ".injected").ConfigureAwait(false);
+                compilation = compilation.RemoveAllSyntaxTrees().AddSyntaxTrees(newSyntaxTrees);
+            }
+        }
+        CompilationWithAnalyzers analyticCompilation = null;
+        if (whitelistAnalyzer != null)
+        {
+            analyticCompilation = compilation.WithAnalyzers(ImmutableArray.Create(whitelistAnalyzer));
+            compilation = (CSharpCompilation)analyticCompilation.Compilation;
+        }
+
+        using var assemblyStream = new MemoryStream();
+
+        var emitResult = compilation.Emit(assemblyStream);
+        var success = emitResult.Success;
+        var myBlacklistSyntaxVisitor = new MyBlacklistSyntaxVisitor();
+        foreach (var syntaxTree in compilation.SyntaxTrees)
+        {
+            myBlacklistSyntaxVisitor.SetSemanticModel(compilation.GetSemanticModel(syntaxTree, false));
+            myBlacklistSyntaxVisitor.Visit(await syntaxTree.GetRootAsync());
+        }
+        if (myBlacklistSyntaxVisitor.HasAnyResult())
+        {
+            myBlacklistSyntaxVisitor.GetResultMessages(messages);
+        }
+        else
+        {
+            success = await EmitDiagnostics(MyScriptCompiler.Static, analyticCompilation, emitResult, messages, success).ConfigureAwait(false);
+            await WriteDiagnostics2(MyScriptCompiler.Static, target, assemblyName, messages, success).ConfigureAwait(false);
+            assemblyStream.Seek(0, SeekOrigin.Begin);
+            if (injectionFailed) return null;
+            if (success)
+                return context.LoadFromStream(assemblyStream);
+
+            await EmitDiagnostics(MyScriptCompiler.Static, analyticCompilation, compilationWithoutInjection.Emit(assemblyStream), messages, false).ConfigureAwait(false);
+        }
+
+        return null;
+    }
+
+    private readonly CSharpCompilationOptions _compilationOptions = new(OutputKind.DynamicallyLinkedLibrary);
+    private readonly CSharpParseOptions _parseOptions = new(LanguageVersion.CSharp10, DocumentationMode.None);
+    
+    private CSharpCompilation CreateCompilation(string assemblyFileName, IEnumerable<Script> scripts)
+    {
+        if (scripts == null)
+            return CSharpCompilation.Create(assemblyFileName, null, MetadataReferencesGetter(MyScriptCompiler.Static),
+                                            _compilationOptions);
+        
+        var parseOptions = _parseOptions.WithPreprocessorSymbols(MyScriptCompiler.Static.ConditionalCompilationSymbols);
+        var enumerable = scripts.Select(s => CSharpSyntaxTree.ParseText(s.Code, parseOptions, s.Name, Encoding.UTF8));
+        
+        return CSharpCompilation.Create(assemblyFileName, enumerable, MetadataReferencesGetter(MyScriptCompiler.Static), _compilationOptions);
+    }
+}

Torch/Patches/ProgramableBlockPatch.cs

@@ -0,0 +1,33 @@
+using System;
+using System.Reflection;
+using Sandbox.Game.Entities.Blocks;
+using Sandbox.Game.World;
+using Torch.API.Managers;
+using Torch.Managers;
+using Torch.Managers.PatchManager;
+using Torch.Utils;
+
+namespace Torch.Patches;
+
+[PatchShim]
+public static class ProgramableBlockPatch
+{
+    [ReflectedMethodInfo(typeof(MyProgrammableBlock), "Compile")]
+    private static MethodInfo CompileMethod = null!;
+    
+    public static void Patch(PatchContext context)
+    {
+        context.GetPattern(CompileMethod).AddPrefix();
+    }
+
+    private static bool Prefix(MyProgrammableBlock __instance, string program, string storage, bool instantiate)
+    {
+        if (!MySession.Static.EnableIngameScripts || __instance.CubeGrid is {IsPreview: true} or {CreatePhysics: false})
+            return false;
+
+#pragma warning disable CS0618
+        TorchBase.Instance.CurrentSession.Managers.GetManager<ScriptCompilationManager>().CompileAsync(__instance, program, storage, instantiate);
+#pragma warning restore CS0618
+        return false;
+    }
+}

Torch/TorchBase.cs

@@ -124,6 +124,7 @@ namespace Torch
             sessionManager.AddFactory((x) => Sync.IsServer ? new ChatManagerServer(this) : new ChatManagerClient(this));
             sessionManager.AddFactory((x) => Sync.IsServer ? new CommandManager(this) : null);
             sessionManager.AddFactory((x) => new EntityManager(this));
+            sessionManager.AddFactory((x) => new ScriptCompilationManager(this));
 
             Managers.AddManager(sessionManager);
             Managers.AddManager(new PatchManager(this));