feat: adding code gen extensions asmdef

code gen base classes that can be shared by other asmdef other than the main weaver

Assets/Mirage/Weaver/Mirage.CecilExtensions/AssemblyInfo.cs

@@ -0,0 +1,3 @@
+using System.Reflection;
+
+[assembly: AssemblyVersion("0.1.0")] 

Assets/Mirage/Weaver/Mirage.CecilExtensions/README.md

@@ -0,0 +1,3 @@
+# Mirage.Cecil
+
+Extensions to help use Mono.Cecil inside Unity

Assets/Mirage/Weaver/Mirage.CecilExtensions/Unity.Mirage.CecilExtensions.CodeGen.asmdef

@@ -0,0 +1,21 @@
+{
+    "name": "Unity.Mirage.CecilExtensions.CodeGen",
+    "rootNamespace": "",
+    "references": [],
+    "includePlatforms": [
+        "Editor"
+    ],
+    "excludePlatforms": [],
+    "allowUnsafeCode": true,
+    "overrideReferences": true,
+    "precompiledReferences": [
+        "Mono.Cecil.dll",
+        "Mono.Cecil.Rocks.dll",
+        "Mono.Cecil.Mdb.dll",
+        "Mono.Cecil.Pdb.dll"
+    ],
+    "autoReferenced": false,
+    "defineConstraints": [],
+    "versionDefines": [],
+    "noEngineReferences": false
+}

Assets/Mirage/Weaver/Mirage.CecilExtensions/WeaverBase.cs

@@ -0,0 +1,119 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+using Unity.CompilationPipeline.Common.Diagnostics;
+using Unity.CompilationPipeline.Common.ILPostProcessing;
+
+namespace Mirage.CodeGen
+{
+    /// <summary>
+    /// Use as a base class for custom IL weaver. This class will read and write the AssemblyDefinition and return the results.
+    /// </summary>
+    public abstract class WeaverBase
+    {
+        public virtual string Name => this.GetType().FullName;
+
+        public readonly IWeaverLogger logger;
+
+        /// <summary>
+        /// Results from <see cref="Process(ICompiledAssembly)"/>
+        /// </summary>
+        public AssemblyDefinition AssemblyDefinition { get; private set; }
+
+        public WeaverBase(IWeaverLogger logger = null)
+        {
+            this.logger = logger ?? new WeaverLogger();
+        }
+
+        public enum Result
+        {
+            Success,
+            NoChanges,
+            Failed,
+        }
+
+        protected abstract Result Process(AssemblyDefinition assembly);
+
+        public ILPostProcessResult Process(ICompiledAssembly compiledAssembly)
+        {
+            try
+            {
+                this.AssemblyDefinition = ReadAssembly(compiledAssembly);
+
+                var result = this.Process(this.AssemblyDefinition);
+
+                if (result == Result.Success)
+                    return this.Success();
+                else if (result == Result.Failed)
+                    return this.Failed();
+                else // no changes, no results
+                    return null;
+            }
+            catch (Exception e)
+            {
+                // this means that Weaver had problems
+                // we should never get here unless there is a bug in the implementation
+                // for problems with user code, use logger instead of throwing so that multiple errors can be reported to the user.
+
+                return this.Error(e);
+            }
+        }
+
+        private ILPostProcessResult Success()
+        {
+            // write assembly to file on success
+            var pe = new MemoryStream();
+            var pdb = new MemoryStream();
+
+            var writerParameters = new WriterParameters
+            {
+                SymbolWriterProvider = new PortablePdbWriterProvider(),
+                SymbolStream = pdb,
+                WriteSymbols = true
+            };
+
+            this.AssemblyDefinition.Write(pe, writerParameters);
+            return new ILPostProcessResult(new InMemoryAssembly(pe.ToArray(), pdb.ToArray()), this.logger.GetDiagnostics());
+        }
+
+        private ILPostProcessResult Failed()
+        {
+            return new ILPostProcessResult(null, this.logger.GetDiagnostics());
+        }
+
+        private ILPostProcessResult Error(Exception e)
+        {
+            var message = new DiagnosticMessage
+            {
+                DiagnosticType = DiagnosticType.Error,
+                MessageData = $"Weaver {this.Name} failed on {this.AssemblyDefinition?.Name} because of Exception: {e}",
+            };
+            return new ILPostProcessResult(null, new List<DiagnosticMessage> { message });
+        }
+
+        private static AssemblyDefinition ReadAssembly(ICompiledAssembly compiledAssembly)
+        {
+            var assemblyResolver = new PostProcessorAssemblyResolver(compiledAssembly);
+            var readerParameters = new ReaderParameters
+            {
+                SymbolStream = new MemoryStream(compiledAssembly.InMemoryAssembly.PdbData),
+                SymbolReaderProvider = new PortablePdbReaderProvider(),
+                AssemblyResolver = assemblyResolver,
+                ReflectionImporterProvider = new PostProcessorReflectionImporterProvider(),
+                ReadingMode = ReadingMode.Immediate
+            };
+
+            var assemblyDefinition = AssemblyDefinition.ReadAssembly(new MemoryStream(compiledAssembly.InMemoryAssembly.PeData), readerParameters);
+
+            // apparently, it will happen that when we ask to resolve a type that lives inside the MyRuntime.asmdef, and we
+            // are also postprocessing MyRuntime.asmdef, type resolving will fail, because we do not actually try to resolve
+            // inside the assembly we are processing. Let's make sure we do that, so that we can use postprocessor features inside
+            // MyRuntime.asmdef itself as well.
+            assemblyResolver.AddAssemblyDefinitionBeingOperatedOn(assemblyDefinition);
+
+            return assemblyDefinition;
+        }
+    }
+}

Assets/Mirage/Weaver/Unity.Mirage.CodeGen.asmdef

@@ -1,8 +1,10 @@
 {
     "name": "Unity.Mirage.CodeGen",
+    "rootNamespace": "",
     "references": [
-        "Mirage",
-        "UniTask"
+        "GUID:30817c1a0e6d646d99c048fc403f5979",
+        "GUID:f51ebe6a0ceec4240a699833d6309b23",
+        "GUID:f403fea27ba781d4790352849c7c1802"
     ],
     "includePlatforms": [
         "Editor"