PoC using dev branch of LibCpp2Il

README.md

@@ -1,13 +1,19 @@
 protodec
 ========
-A tool to decompile protobuf classes compiled by [protoc](https://github.com/protocolbuffers/protobuf), from CIL assemblies back into .proto definitions.
+A tool to decompile protobuf classes compiled by [protoc](https://github.com/protocolbuffers/protobuf), from il2cpp compiled CIL assemblies back into .proto definitions.
+
+This branch was created as a proof-of-concept using [the development branch of LibCpp2Il](https://github.com/SamboyCoding/Cpp2IL/tree/development/LibCpp2IL) to parse the game assembly and metadata directly, without the intermediate step of generating dummy DLLs.
+
+I offer no guarantees that this branch functions 1:1 with master, it may explode.
 
 Usage
 -----
 ```
-Usage: protodec(.exe) <target_assembly_path> <out_path> [options]
+Usage: protodec(.exe) <game_assembly_path> <global_metadata_path> <unity_version> <out_path> [options]
 Arguments:
-  target_assembly_path  Either the path to the target assembly or a directory of assemblies, all of which be parsed.
+  game_assembly_path    The path to the game assembly DLL.
+  global_metadata_path  The path to the global-metadata.dat file.
+  unity_version         The version of Unity which was used to create the metadata file or alternatively, the path to the globalgamemanagers or the data.unity3d file.
   out_path              An existing directory to output into individual files, otherwise output to a single file.
 Options:
   --debug                                                     Drops the minimum log level to Debug.
@@ -22,8 +28,9 @@ Limitations
 -----------
 - Integers are assumed to be (u)int32/64 as CIL doesn't differentiate between them and sint32/64 and (s)fixed32/64.
 - Package names are not preserved in protobuf compilation so naturally we cannot recover them during decompilation, which may result in naming conflicts.
-- When decompiling from [Il2CppDumper](https://github.com/Perfare/Il2CppDumper) DummyDLLs
+- Due to the development branch of Cpp2Il not yet recovering method bodies
-    - The `Name` parameter of `OriginalNameAttribute` is not dumped. In this case, the CIL enum field names are used after conforming them to protobuf conventions
+    - The `Name` parameter of `OriginalNameAttribute` is not parsed. In this case, the CIL enum field names are used after conforming them to protobuf conventions.
+    - The `Tool` parameter of `GeneratedCodeAttribute` is not compared against when parsing gRPC service methods, which may cause false positives in the event that another tool has generated methods in the service class.
 
 License
 -------

protodec.sln

@@ -12,6 +12,10 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution
 		README.md = README.md
 	EndProjectSection
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "LibCpp2IL", "..\Cpp2IL\LibCpp2IL\LibCpp2IL.csproj", "{42B987D9-E551-48BC-A821-F7411C664ECC}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WasmDisassembler", "..\Cpp2IL\WasmDisassembler\WasmDisassembler.csproj", "{07C0845C-7579-43C0-B4C9-4769573F3A24}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -26,6 +30,14 @@ Global
 		{5F6DAD82-D9AD-4CE5-86E6-D20C9F059A4D}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{5F6DAD82-D9AD-4CE5-86E6-D20C9F059A4D}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{5F6DAD82-D9AD-4CE5-86E6-D20C9F059A4D}.Release|Any CPU.Build.0 = Release|Any CPU
+		{42B987D9-E551-48BC-A821-F7411C664ECC}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{42B987D9-E551-48BC-A821-F7411C664ECC}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{42B987D9-E551-48BC-A821-F7411C664ECC}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{42B987D9-E551-48BC-A821-F7411C664ECC}.Release|Any CPU.Build.0 = Release|Any CPU
+		{07C0845C-7579-43C0-B4C9-4769573F3A24}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{07C0845C-7579-43C0-B4C9-4769573F3A24}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{07C0845C-7579-43C0-B4C9-4769573F3A24}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{07C0845C-7579-43C0-B4C9-4769573F3A24}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

src/LibProtodec/LibProtodec.csproj

@@ -18,6 +18,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <ProjectReference Include="..\..\..\Cpp2IL\LibCpp2IL\LibCpp2IL.csproj" />
     <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="9.0.0-preview.5.24306.7" />
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All" />
     <PackageReference Include="System.Reflection.MetadataLoadContext" Version="9.0.0-preview.5.24306.7" />

src/LibProtodec/Loaders/Il2CppAssemblyLoader.cs

@@ -0,0 +1,38 @@
+// Copyright © 2024 Xpl0itR
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+using System.Linq;
+using AssetRipper.Primitives;
+using CommunityToolkit.Diagnostics;
+using LibCpp2IL;
+using LibCpp2IL.Metadata;
+using LibCpp2IL.Reflection;
+using LibProtodec.Models.Cil;
+using LibProtodec.Models.Cil.Il2Cpp;
+using Microsoft.Extensions.Logging;
+
+namespace LibProtodec.Loaders;
+
+public sealed class Il2CppAssemblyLoader : CilAssemblyLoader
+{
+    public Il2CppAssemblyLoader(string assemblyPath, string metadataPath, UnityVersion unityVersion, ILogger logger)
+    {
+        if (!LibCpp2IlMain.LoadFromFile(assemblyPath, metadataPath, unityVersion))
+            ThrowHelper.ThrowInvalidDataException("Failed to load il2cpp assembly!");
+
+        this.LoadedTypes = LibCpp2IlMain.TheMetadata!.typeDefs.Select(Il2CppType.GetOrCreate).ToList();
+
+        logger?.LogLoadedTypeAndAssemblyCount(this.LoadedTypes.Count, LibCpp2IlMain.TheMetadata.imageDefinitions.Length);
+    }
+
+    protected override ICilType FindType(string typeFullName, string assemblySimpleName)
+    {
+        Il2CppTypeDefinition? type = LibCpp2IlReflection.GetTypeByFullName(typeFullName);
+        Guard.IsNotNull(type);
+
+        return Il2CppType.GetOrCreate(type);
+    }
+}

src/LibProtodec/Models/Cil/Il2Cpp/Il2CppAttribute.cs

@@ -0,0 +1,20 @@
+// Copyright © 2024 Xpl0itR
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+using System;
+using System.Collections.Generic;
+using LibCpp2IL.Reflection;
+
+namespace LibProtodec.Models.Cil.Il2Cpp;
+
+public sealed class Il2CppAttribute(Il2CppTypeReflectionData il2CppAttrType) : ICilAttribute
+{
+    public ICilType Type =>
+        Il2CppType.GetOrCreate(il2CppAttrType);
+
+    public IList<object?> ConstructorArgumentValues =>
+        throw new NotImplementedException();
+}

src/LibProtodec/Models/Cil/Il2Cpp/Il2CppField.cs

@@ -0,0 +1,40 @@
+// Copyright © 2024 Xpl0itR
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+using System.Reflection;
+using LibCpp2IL.Metadata;
+
+namespace LibProtodec.Models.Cil.Il2Cpp;
+
+public sealed class Il2CppField(Il2CppFieldDefinition il2CppField) : Il2CppMember, ICilField
+{
+    private readonly FieldAttributes _attributes =
+        (FieldAttributes)il2CppField.RawFieldType!.Attrs;
+
+    public string Name =>
+        il2CppField.Name!;
+
+    public object? ConstantValue =>
+        il2CppField.DefaultValue!.Value;
+
+    public bool IsLiteral =>
+        (_attributes & FieldAttributes.Literal) != 0;
+
+    public bool IsPublic =>
+        (_attributes & FieldAttributes.Public) != 0;
+
+    public bool IsStatic =>
+        (_attributes & FieldAttributes.Static) != 0;
+
+    protected override Il2CppImageDefinition DeclaringAssembly =>
+        il2CppField.FieldType!.baseType!.DeclaringAssembly!;
+
+    protected override int CustomAttributeIndex =>
+        il2CppField.customAttributeIndex;
+
+    protected override uint Token =>
+        il2CppField.token;
+}

src/LibProtodec/Models/Cil/Il2Cpp/Il2CppMember.cs

@@ -0,0 +1,63 @@
+// Copyright © 2024 Xpl0itR
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using LibCpp2IL;
+using LibCpp2IL.Metadata;
+
+namespace LibProtodec.Models.Cil.Il2Cpp;
+
+public abstract class Il2CppMember
+{
+    private ICilAttribute[]? _customAttributes;
+
+    public IList<ICilAttribute> CustomAttributes
+    {
+        get
+        {
+            if (_customAttributes is null)
+            {
+                _customAttributes = GetCustomAttributes().ToArray();
+            }
+
+            return _customAttributes;
+        }
+    }
+
+    public IEnumerable<ICilAttribute> GetCustomAttributes()
+    {
+        if (LibCpp2IlMain.MetadataVersion >= 29)
+        {
+            throw new NotImplementedException();
+        }
+
+        Il2CppCustomAttributeTypeRange? attributeTypeRange = LibCpp2IlMain.TheMetadata!.GetCustomAttributeData(
+            DeclaringAssembly, CustomAttributeIndex, Token, out _);
+
+        if (attributeTypeRange is null || attributeTypeRange.count == 0)
+            yield break;
+
+        for (int attrIndex = attributeTypeRange.start,
+                 end = attributeTypeRange.start + attributeTypeRange.count;
+             attrIndex < end;
+             attrIndex++)
+        {
+            int typeIndex = LibCpp2IlMain.TheMetadata.attributeTypes[attrIndex];
+
+            yield return new Il2CppAttribute(
+                LibCpp2ILUtils.GetTypeReflectionData(
+                    LibCpp2IlMain.Binary!.GetType(typeIndex)));
+        }
+    }
+
+    protected abstract Il2CppImageDefinition DeclaringAssembly { get; }
+
+    protected abstract int CustomAttributeIndex { get; }
+
+    protected abstract uint Token { get; }
+}

src/LibProtodec/Models/Cil/Il2Cpp/Il2CppMethod.cs

@@ -0,0 +1,57 @@
+// Copyright © 2024 Xpl0itR
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+using System.Collections.Generic;
+using System.Reflection;
+using LibCpp2IL;
+using LibCpp2IL.Metadata;
+using LibCpp2IL.Reflection;
+
+namespace LibProtodec.Models.Cil.Il2Cpp;
+
+public sealed class Il2CppMethod(Il2CppMethodDefinition il2CppMethod) : Il2CppMember, ICilMethod
+{
+    public string Name =>
+        il2CppMethod.Name!;
+
+    public bool IsInherited =>
+        false;
+
+    public bool IsConstructor =>
+        false;
+
+    public bool IsPublic =>
+        (il2CppMethod.Attributes & MethodAttributes.Public) != 0;
+
+    public bool IsStatic =>
+        (il2CppMethod.Attributes & MethodAttributes.Static) != 0;
+
+    public bool IsVirtual =>
+        (il2CppMethod.Attributes & MethodAttributes.Virtual) != 0;
+
+    public ICilType ReturnType =>
+        Il2CppType.GetOrCreate(
+            LibCpp2ILUtils.GetTypeReflectionData(
+                LibCpp2IlMain.Binary!.GetType(
+                    il2CppMethod.returnTypeIdx)));
+
+    public IEnumerable<ICilType> GetParameterTypes()
+    {
+        foreach (Il2CppParameterReflectionData parameter in il2CppMethod.Parameters!)
+        {
+            yield return Il2CppType.GetOrCreate(parameter.Type);
+        }
+    }
+
+    protected override Il2CppImageDefinition DeclaringAssembly =>
+        il2CppMethod.DeclaringType!.DeclaringAssembly!;
+
+    protected override int CustomAttributeIndex =>
+        il2CppMethod.customAttributeIndex;
+
+    protected override uint Token =>
+        il2CppMethod.token;
+}

src/LibProtodec/Models/Cil/Il2Cpp/Il2CppProperty.cs

@@ -0,0 +1,54 @@
+// Copyright © 2024 Xpl0itR
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+using System.Linq;
+using LibCpp2IL;
+using LibCpp2IL.Metadata;
+
+namespace LibProtodec.Models.Cil.Il2Cpp;
+
+// We take declaring type as a ctor arg because of the nonsensically inefficient way libcpp2il calculates Il2CppPropertyDefinition's DeclaringType property
+public sealed class Il2CppProperty(Il2CppPropertyDefinition il2CppProperty, Il2CppTypeDefinition declaringType) : Il2CppMember, ICilProperty
+{
+    public string Name =>
+        il2CppProperty.Name!;
+
+    public bool IsInherited =>
+        false;
+
+    public bool CanRead =>
+        il2CppProperty.get >= 0;
+
+    public bool CanWrite =>
+        il2CppProperty.set >= 0;
+
+    public ICilMethod? Getter =>
+        CanRead
+            ? new Il2CppMethod(
+                LibCpp2IlMain.TheMetadata!.methodDefs[
+                    declaringType.FirstMethodIdx + il2CppProperty.get])
+            : null;
+
+    public ICilMethod? Setter =>
+        CanWrite
+            ? new Il2CppMethod(
+                LibCpp2IlMain.TheMetadata!.methodDefs[
+                    declaringType.FirstMethodIdx + il2CppProperty.set])
+            : null;
+
+    public ICilType Type =>
+        Getter?.ReturnType
+     ?? Setter!.GetParameterTypes().First();
+
+    protected override Il2CppImageDefinition DeclaringAssembly =>
+        declaringType.DeclaringAssembly!;
+
+    protected override int CustomAttributeIndex =>
+        il2CppProperty.customAttributeIndex;
+
+    protected override uint Token =>
+        il2CppProperty.token;
+}

src/LibProtodec/Models/Cil/Il2Cpp/Il2CppType.cs

@@ -0,0 +1,194 @@
+// Copyright © 2024 Xpl0itR
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using CommunityToolkit.Diagnostics;
+using LibCpp2IL;
+using LibCpp2IL.Metadata;
+using LibCpp2IL.Reflection;
+
+namespace LibProtodec.Models.Cil.Il2Cpp;
+
+public sealed class Il2CppType : Il2CppMember, ICilType
+{
+    private readonly Il2CppTypeDefinition _il2CppType;
+    private readonly Il2CppTypeReflectionData[] _genericArgs;
+    private IList<ICilType>? _genericTypeArguments;
+
+    private Il2CppType(Il2CppTypeDefinition il2CppType, Il2CppTypeReflectionData[] genericArgs) =>
+        (_il2CppType, _genericArgs) = (il2CppType, genericArgs);
+
+    public string Name =>
+        _il2CppType.Name!;
+
+    public string FullName =>
+        _il2CppType.FullName!;
+
+    public string? Namespace =>
+        _il2CppType.Namespace;
+
+    public string DeclaringAssemblyName =>
+        LibCpp2IlMain.TheMetadata!.GetStringFromIndex(
+            DeclaringAssembly.nameIndex);
+
+    public ICilType? DeclaringType =>
+        IsNested
+            ? GetOrCreate(
+                LibCpp2ILUtils.GetTypeReflectionData(
+                    LibCpp2IlMain.Binary!.GetType(
+                        _il2CppType.DeclaringTypeIndex)))
+            : null;
+
+    public ICilType? BaseType =>
+        _il2CppType.ParentIndex == -1
+            ? null
+            : GetOrCreate(
+                LibCpp2ILUtils.GetTypeReflectionData(
+                    LibCpp2IlMain.Binary!.GetType(
+                        _il2CppType.ParentIndex)));
+
+    public bool IsAbstract =>
+        _il2CppType.IsAbstract;
+
+    public bool IsClass =>
+        (_il2CppType.Attributes & TypeAttributes.ClassSemanticsMask) == TypeAttributes.Class
+     && !_il2CppType.IsValueType;
+
+    public bool IsEnum =>
+        _il2CppType.IsEnumType;
+
+    public bool IsNested =>
+        _il2CppType.DeclaringTypeIndex >= 0;
+
+    public bool IsSealed =>
+        (_il2CppType.Attributes & TypeAttributes.Sealed) != 0;
+
+    public IList<ICilType> GenericTypeArguments
+    {
+        get
+        {
+            if (_genericTypeArguments is null)
+            {
+                if (_genericArgs.Length < 1)
+                {
+                    _genericTypeArguments = Array.Empty<ICilType>();
+                }
+                else
+                {
+                    _genericTypeArguments = _genericArgs.Select(GetOrCreate).ToList();
+                }
+            }
+
+            return _genericTypeArguments;
+        }
+    }
+
+    public IEnumerable<ICilField> GetFields()
+    {
+        for (int idx = _il2CppType.FirstFieldIdx, end = _il2CppType.FirstFieldIdx + _il2CppType.FieldCount; idx < end; idx++)
+        {
+            yield return new Il2CppField(
+                LibCpp2IlMain.TheMetadata!.fieldDefs[idx]);
+        }
+    }
+
+    public IEnumerable<ICilMethod> GetMethods()
+    {
+        for (int idx = _il2CppType.FirstMethodIdx, end = _il2CppType.FirstMethodIdx + _il2CppType.MethodCount; idx < end; idx++)
+        {
+            yield return new Il2CppMethod(
+                LibCpp2IlMain.TheMetadata!.methodDefs[idx]);
+        }
+    }
+
+    public IEnumerable<ICilType> GetNestedTypes()
+    {
+        for (int idx = _il2CppType.NestedTypesStart, end = _il2CppType.NestedTypesStart + _il2CppType.NestedTypeCount; idx < end; idx++)
+        {
+            yield return GetOrCreate(
+                LibCpp2IlMain.TheMetadata!.typeDefs[
+                    LibCpp2IlMain.TheMetadata.nestedTypeIndices[idx]]);
+        }
+    }
+
+    public IEnumerable<ICilProperty> GetProperties()
+    {
+        for (int idx = _il2CppType.FirstPropertyId, end = _il2CppType.FirstPropertyId + _il2CppType.PropertyCount; idx < end; idx++)
+        {
+            yield return new Il2CppProperty(
+                LibCpp2IlMain.TheMetadata!.propertyDefs[idx],
+                _il2CppType);
+        }
+    }
+
+    public bool IsAssignableTo(ICilType type)
+    {
+        if (type is Il2CppType il2CppType)
+        {
+            return IsAssignableTo(_il2CppType, il2CppType._il2CppType);
+        }
+
+        return ThrowHelper.ThrowNotSupportedException<bool>();
+    }
+
+    protected override Il2CppImageDefinition DeclaringAssembly =>
+        _il2CppType.DeclaringAssembly!;
+
+    protected override int CustomAttributeIndex =>
+        _il2CppType.CustomAttributeIndex;
+
+    protected override uint Token =>
+        _il2CppType.Token;
+
+
+    private static readonly ConcurrentDictionary<string, Il2CppType> TypeLookup = [];
+
+    public static ICilType GetOrCreate(Il2CppTypeDefinition il2CppType) =>
+        TypeLookup.GetOrAdd(
+            il2CppType.FullName!,
+            static (_, il2CppType) =>
+                new Il2CppType(il2CppType, Array.Empty<Il2CppTypeReflectionData>()),
+            il2CppType);
+
+    public static ICilType GetOrCreate(Il2CppTypeReflectionData il2CppTypeData)
+    {
+        Guard.IsTrue(il2CppTypeData.isType);
+
+        return TypeLookup.GetOrAdd(
+            il2CppTypeData.ToString(),
+            static (_, il2CppTypeData) =>
+                new Il2CppType(il2CppTypeData.baseType!, il2CppTypeData.genericParams),
+            il2CppTypeData);
+    }
+
+    private static bool IsAssignableTo(Il2CppTypeDefinition thisType, Il2CppTypeDefinition baseType)
+    {
+        if (baseType.IsInterface)
+        {
+            foreach (Il2CppTypeReflectionData @interface in thisType.Interfaces!)
+            {
+                if (@interface.baseType == baseType)
+                {
+                    return true;
+                }
+            }
+        }
+        
+        if (thisType == baseType)
+        {
+            return true;
+        }
+
+        Il2CppTypeDefinition? thisTypeBaseType = thisType.BaseType?.baseType;
+
+        return thisTypeBaseType is not null
+            && IsAssignableTo(thisTypeBaseType, baseType);
+    }
+}

src/LibProtodec/ProtodecContext.cs

@@ -572,11 +572,7 @@ public class ProtodecContext
 
     protected string TranslateEnumFieldName(IEnumerable<ICilAttribute> attributes, string fieldName, string enumName)
     {
-        if (attributes.SingleOrDefault(static attr => attr.Type.Name == "OriginalNameAttribute")
+        //TODO: parse original name from first parameter of OriginalNameAttribute constructor
-                     ?.ConstructorArgumentValues[0] is string originalName)
-        {
-            return originalName;
-        }
 
         if (NameLookup?.Invoke(fieldName, out string? translatedName) == true)
         {
@@ -626,9 +622,11 @@ public class ProtodecContext
     protected static bool IsBeebyted(string name) =>
         name.Length == 11 && name.CountUpper() == 11;
 
-    protected static bool HasGeneratedCodeAttribute(IEnumerable<ICilAttribute> attributes, string tool) =>
+    protected static bool HasGeneratedCodeAttribute(IEnumerable<ICilAttribute> attributes, string tool)
-        attributes.Any(attr => attr.Type.Name                              == nameof(GeneratedCodeAttribute)
+    {
-                            && attr.ConstructorArgumentValues[0] as string == tool);
+        return attributes.Any(attr => attr.Type.Name == nameof(GeneratedCodeAttribute));
+        //TODO: ensure the first argument of the GeneratedCodeAttribute constructor == tool parameter
+    }
 
     protected static bool HasNonUserCodeAttribute(IEnumerable<ICilAttribute> attributes) =>
         attributes.Any(static attr => attr.Type.Name == nameof(DebuggerNonUserCodeAttribute));

src/protodec/Program.cs

@@ -9,6 +9,8 @@ using System.CodeDom.Compiler;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using AssetRipper.Primitives;
+using LibCpp2IL;
 using LibProtodec;
 using LibProtodec.Loaders;
 using LibProtodec.Models.Cil;
@@ -17,9 +19,11 @@ using Microsoft.Extensions.Logging;
 
 const string indent = "  ";
 const string help   = """
-    Usage: protodec(.exe) <target_assembly_path> <out_path> [options]
+    Usage: protodec(.exe) <game_assembly_path> <global_metadata_path> <unity_version> <out_path> [options]
     Arguments:
-      target_assembly_path  Either the path to the target assembly or a directory of assemblies, all of which be parsed.
+      game_assembly_path    The path to the game assembly DLL.
+      global_metadata_path  The path to the global-metadata.dat file.
+      unity_version         The version of Unity which was used to create the metadata file or alternatively, the path to the globalgamemanagers or the data.unity3d file.
       out_path              An existing directory to output into individual files, otherwise output to a single file.
     Options:
       --debug                                                     Drops the minimum log level to Debug.
@@ -30,14 +34,16 @@ const string help   = """
       --include_service_methods_without_generated_code_attribute  Includes methods that aren't decorated with `GeneratedCode("grpc_csharp_plugin")` when parsing gRPC services.
     """;
 
-if (args.Length < 2)
+if (args.Length < 4)
 {
     Console.WriteLine(help);
     return;
 }
 
 string        assembly = args[0];
-string        outPath  = Path.GetFullPath(args[1]);
+string        metadata = args[1];
+string        uVersion = args[2];
+string        outPath  = Path.GetFullPath(args[3]);
 ParserOptions options  = ParserOptions.None;
 LogLevel      logLevel = args.Contains("--debug")
     ? LogLevel.Debug
@@ -52,14 +58,23 @@ if (args.Contains("--include_properties_without_non_user_code_attribute"))
 if (args.Contains("--include_service_methods_without_generated_code_attribute"))
     options |= ParserOptions.IncludeServiceMethodsWithoutGeneratedCodeAttribute;
 
+if (!UnityVersion.TryParse(uVersion, out UnityVersion unityVersion, out _))
+{
+    unityVersion = uVersion.EndsWith("globalgamemanagers")
+        ? LibCpp2IlMain.GetVersionFromGlobalGameManagers(
+            File.ReadAllBytes(uVersion))
+        : LibCpp2IlMain.GetVersionFromDataUnity3D(
+            File.OpenRead(uVersion));
+}
+
 using ILoggerFactory loggerFactory = LoggerFactory.Create(
     builder => builder.AddSimpleConsole(static console => console.IncludeScopes = true)
                       .SetMinimumLevel(logLevel));
 ILogger logger = loggerFactory.CreateLogger("protodec");
 
 logger.LogInformation("Loading target assemblies...");
-using CilAssemblyLoader loader = new ClrAssemblyLoader(
+using CilAssemblyLoader loader = new Il2CppAssemblyLoader(
-    assembly, loggerFactory.CreateLogger<ClrAssemblyLoader>());
+    assembly, metadata, unityVersion, loggerFactory.CreateLogger<Il2CppAssemblyLoader>());
 
 ProtodecContext ctx = new()
 {