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.
   out_path              An existing directory to output into individual files, otherwise output to a single file.
 Options:
   --parse_service_servers                                     Parses gRPC service definitions from server classes.
@@ -21,8 +27,9 @@ 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
-    - The `Name` parameter of `OriginalNameAttribute` is not dumped. In this case, the CIL enum field names are used after conforming them to protobuf conventions
+- Due to the development branch of Cpp2Il not yet recovering method bodies
+    - 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/AssemblyInspector.cs

@@ -1,91 +0,0 @@
-// Copyright © 2023-2024 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.IO;
-using System.Linq;
-using System.Reflection;
-
-namespace LibProtodec;
-
-public sealed class AssemblyInspector : IDisposable
-{
-    public readonly MetadataLoadContext AssemblyContext;
-    public readonly IReadOnlyList<Type> LoadedTypes;
-
-    public AssemblyInspector(string assemblyPath)
-    {
-        bool   isFile      = File.Exists(assemblyPath);
-        string assemblyDir = isFile
-            ? Path.GetDirectoryName(assemblyPath)!
-            : assemblyPath;
-
-        PermissiveAssemblyResolver assemblyResolver = new(
-            Directory.EnumerateFiles(assemblyDir, searchPattern: "*.dll"));
-
-        AssemblyContext = new MetadataLoadContext(assemblyResolver);
-        LoadedTypes     = isFile
-            ? AssemblyContext.LoadFromAssemblyPath(assemblyPath).GetTypes()
-            : assemblyResolver.AssemblyPathLookup.Values.SelectMany(path => AssemblyContext.LoadFromAssemblyPath(path).GetTypes()).ToList();
-    }
-
-    public IEnumerable<Type> GetProtobufMessageTypes()
-    {
-        Type? iMessage = LoadedTypes.SingleOrDefault(static type => type?.FullName == "Google.Protobuf.IMessage", null)
-                      ?? AssemblyContext.LoadFromAssemblyName("Google.Protobuf")
-                                        .GetType("Google.Protobuf.IMessage");
-
-        return LoadedTypes.Where(
-            type => type is { IsNested: false, IsSealed: true }
-                 && type.Namespace?.StartsWith("Google.Protobuf", StringComparison.Ordinal) != true
-                 && type.IsAssignableTo(iMessage));
-    }
-
-    public IEnumerable<Type> GetProtobufServiceClientTypes()
-    {
-        Type? clientBase = LoadedTypes.SingleOrDefault(static type => type?.FullName == "Grpc.Core.ClientBase", null)
-                        ?? AssemblyContext.LoadFromAssemblyName("Grpc.Core.Api")
-                                          .GetType("Grpc.Core.ClientBase");
-
-        return LoadedTypes.Where(
-            type => type is { IsNested: true, IsAbstract: false }
-                 && type.IsAssignableTo(clientBase));
-    }
-
-    public IEnumerable<Type> GetProtobufServiceServerTypes()
-    {
-        Type? bindServiceMethodAttribute = LoadedTypes.SingleOrDefault(static type => type?.FullName == "Grpc.Core.BindServiceMethodAttribute", null)
-                                        ?? AssemblyContext.LoadFromAssemblyName("Grpc.Core.Api")
-                                                          .GetType("Grpc.Core.BindServiceMethodAttribute");
-
-        return LoadedTypes.Where(
-            type => type is { IsNested: true, IsAbstract: true, DeclaringType: { IsNested: false, IsSealed: true, IsAbstract: true } }
-                 && type.GetCustomAttributesData().Any(attribute => attribute.AttributeType == bindServiceMethodAttribute));
-    }
-
-    public void Dispose() =>
-        AssemblyContext.Dispose();
-
-    /// <summary>
-    ///     An assembly resolver that uses paths to every assembly that may be loaded.
-    ///     The file name is expected to be the same as the assembly's simple name (casing ignored).
-    ///     PublicKeyToken, Version and CultureName are ignored.
-    /// </summary>
-    private sealed class PermissiveAssemblyResolver(IEnumerable<string> assemblyPaths) : MetadataAssemblyResolver
-    {
-        public readonly IReadOnlyDictionary<string, string> AssemblyPathLookup =
-            assemblyPaths.ToDictionary(
-                static path => Path.GetFileNameWithoutExtension(path),
-                StringComparer.OrdinalIgnoreCase);
-
-        /// <inheritdoc />
-        public override Assembly? Resolve(MetadataLoadContext mlc, AssemblyName assemblyName) =>
-            AssemblyPathLookup.TryGetValue(assemblyName.Name!, out string? assemblyPath)
-                ? mlc.LoadFromAssemblyPath(assemblyPath)
-                : null;
-    }
-}

src/LibProtodec/Il2CppLoader.cs

@@ -0,0 +1,68 @@
+// 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 AssetRipper.Primitives;
+using CommunityToolkit.Diagnostics;
+using LibCpp2IL;
+using LibCpp2IL.Metadata;
+using LibCpp2IL.Reflection;
+
+namespace LibProtodec;
+
+public sealed class Il2CppLoader : IDisposable
+{
+    public Il2CppLoader(string assemblyPath, string metadataPath, UnityVersion unityVersion)
+    {
+        if (!LibCpp2IlMain.LoadFromFile(assemblyPath, metadataPath, unityVersion))
+            ThrowHelper.ThrowInvalidDataException("Failed to load il2cpp assembly!");
+    }
+
+    public IReadOnlyList<Il2CppTypeDefinition> LoadedTypes =>
+        LibCpp2IlMain.TheMetadata!.typeDefs;
+
+    public IEnumerable<Il2CppTypeDefinition> GetProtobufMessageTypes()
+    {
+        Il2CppTypeDefinition? iMessage = LibCpp2IlReflection.GetTypeByFullName("Google.Protobuf.IMessage");
+        Guard.IsNotNull(iMessage);
+
+        return LoadedTypes.Where(
+            type => !type.IsNested()
+                 && type.IsSealed()
+                 && type.Namespace?.StartsWith("Google.Protobuf", StringComparison.Ordinal) != true
+                 && type.IsAssignableTo(iMessage));
+    }
+
+    public IEnumerable<Il2CppTypeDefinition> GetProtobufServiceClientTypes()
+    {
+        Il2CppTypeDefinition? clientBase = LibCpp2IlReflection.GetTypeByFullName("Grpc.Core.ClientBase");
+        Guard.IsNotNull(clientBase);
+
+        return LoadedTypes.Where(
+            type => type.IsNested()
+                 && !type.IsAbstract
+                 && type.IsAssignableTo(clientBase));
+    }
+
+    public IEnumerable<Il2CppTypeDefinition> GetProtobufServiceServerTypes()
+    {
+        Il2CppTypeDefinition? bindServiceMethodAttribute = LibCpp2IlReflection.GetTypeByFullName("Grpc.Core.BindServiceMethodAttribute");
+        Guard.IsNotNull(bindServiceMethodAttribute);
+
+        return LoadedTypes.Where(
+            type => type.IsNested()
+                 && type is { IsAbstract: true, DeclaringType: not null }
+                 && !type.DeclaringType.IsNested()
+                 && type.DeclaringType.IsSealed()
+                 && type.DeclaringType.IsAbstract
+                 && type.GetCustomAttributeTypes().Any(attributeType => attributeType == bindServiceMethodAttribute));
+    }
+
+    public void Dispose() =>
+        LibCpp2IlMain.Reset();
+}

src/LibProtodec/Il2CppReflectionExtensions.cs

@@ -0,0 +1,105 @@
+// 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.Linq;
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using LibCpp2IL;
+using LibCpp2IL.Metadata;
+
+namespace LibProtodec;
+
+// ReSharper disable LoopCanBeConvertedToQuery
+public static class Il2CppReflectionExtensions
+{
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool IsClass(this Il2CppTypeDefinition type) =>
+        (type.Attributes & TypeAttributes.ClassSemanticsMask) == TypeAttributes.Class;
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool IsNested(this Il2CppTypeDefinition type) =>
+        type.DeclaringType is not null;
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool IsSealed(this Il2CppTypeDefinition type) =>
+        (type.Attributes & TypeAttributes.Sealed) != 0;
+
+    public static IEnumerable<Il2CppTypeDefinition> GetCustomAttributeTypes(this Il2CppTypeDefinition type) =>
+        GetAttributeTypes(
+            LibCpp2IlMain.TheMetadata!.GetCustomAttributeData(
+                type.DeclaringAssembly!, type.CustomAttributeIndex, type.Token, out _));
+
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool IsVirtual(this Il2CppMethodDefinition method) =>
+        (method.Attributes & MethodAttributes.Virtual) != 0;
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool IsNonPublic(this Il2CppMethodDefinition method) =>
+        (method.Attributes & MethodAttributes.Public) == 0;
+
+    public static IEnumerable<Il2CppTypeDefinition> GetCustomAttributeTypes(this Il2CppMethodDefinition method) =>
+        GetAttributeTypes(
+            LibCpp2IlMain.TheMetadata!.GetCustomAttributeData(
+                method.DeclaringType!.DeclaringAssembly!, method.customAttributeIndex, method.token, out _));
+
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool CanRead(this Il2CppPropertyDefinition property) =>
+        property.get >= 0;
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool CanWrite(this Il2CppPropertyDefinition property) =>
+        property.set >= 0;
+
+    public static IEnumerable<Il2CppTypeDefinition> GetCustomAttributeTypes(this Il2CppPropertyDefinition property) =>
+        GetAttributeTypes(
+            LibCpp2IlMain.TheMetadata!.GetCustomAttributeData(
+                property.DeclaringType!.DeclaringAssembly!, property.customAttributeIndex, property.token, out _));
+
+    public static IEnumerable<Il2CppTypeDefinition> GetCustomAttributeTypes(this Il2CppFieldDefinition field) =>
+        GetAttributeTypes(
+            LibCpp2IlMain.TheMetadata!.GetCustomAttributeData(
+                field.FieldType!.baseType!.DeclaringAssembly!, field.customAttributeIndex, field.token, out _));
+
+
+    public static IEnumerable<Il2CppFieldDefinition> GetFields(this Il2CppTypeDefinition type, FieldAttributes fieldAttributes)
+    {
+        foreach (Il2CppFieldDefinition field in type.Fields!)
+        {
+            if (((FieldAttributes)field.RawFieldType!.Attrs & fieldAttributes) == fieldAttributes)
+                yield return field;
+        }
+    }
+
+    public static bool IsAssignableTo(this Il2CppTypeDefinition thisType, Il2CppTypeDefinition baseType)
+    {
+        if ((baseType.IsInterface && thisType.Interfaces!.Any(reflectionData => reflectionData.baseType == baseType))
+         || thisType == baseType)
+        {
+            return true;
+        }
+
+        Il2CppTypeDefinition? thisTypeBaseType = thisType.BaseType?.baseType;
+
+        return thisTypeBaseType is not null
+            && IsAssignableTo(thisTypeBaseType, baseType);
+    }
+
+    private static IEnumerable<Il2CppTypeDefinition> GetAttributeTypes(Il2CppCustomAttributeTypeRange? attributeTypeRange)
+    {
+        if (attributeTypeRange is null)
+            yield break;
+
+        for (int i = attributeTypeRange.start, end = attributeTypeRange.start + attributeTypeRange.count; i < end; i++)
+        {
+            int j = LibCpp2IlMain.TheMetadata!.attributeTypes[i];
+
+            yield return LibCpp2IlMain.Binary!.GetType(j).AsClass();
+        }
+    }
+}

src/LibProtodec/LibProtodec.csproj

@@ -19,8 +19,8 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All" />
-    <PackageReference Include="System.Reflection.MetadataLoadContext" Version="8.0.0" />
-    <PackageReference Include="Xpl0itR.SystemEx" Version="1.1.0" />
+    <ProjectReference Include="..\..\..\Cpp2IL\LibCpp2IL\LibCpp2IL.csproj" />
+    <PackageReference Include="Xpl0itR.SystemEx" Version="1.2.0" />
   </ItemGroup>
 
 </Project>

src/LibProtodec/Models/TopLevels/Message.cs

@@ -14,7 +14,7 @@ namespace LibProtodec.Models.TopLevels;
 
 public sealed class Message : TopLevel, INestableType
 {
-    public readonly Dictionary<string, int[]>         OneOfs = [];
+    public readonly Dictionary<string, List<int>>     OneOfs = [];
     public readonly Dictionary<int, MessageField>     Fields = [];
     public readonly Dictionary<string, INestableType> Nested = [];
 
@@ -30,8 +30,7 @@ public sealed class Message : TopLevel, INestableType
             Protobuf.WriteOptionTo(writer, "deprecated", "true");
         }
 
-        int[] oneOfs = OneOfs.SelectMany(static oneOf => oneOf.Value).ToArray();
-
+        List<int> oneOfs = OneOfs.SelectMany(static oneOf => oneOf.Value).ToList();
         foreach (MessageField field in Fields.Values)
         {
             if (oneOfs.Contains(field.Id))
@@ -40,7 +39,7 @@ public sealed class Message : TopLevel, INestableType
             field.WriteTo(writer, this, isOneOf: false);
         }
 
-        foreach ((string name, int[] fieldIds) in OneOfs)
+        foreach ((string name, List<int> fieldIds) in OneOfs)
         {
             // ReSharper disable once StringLiteralTypo
             writer.Write("oneof ");

src/LibProtodec/ProtodecContext.cs

@@ -13,6 +13,8 @@ using System.Linq;
 using System.Reflection;
 using SystemEx;
 using CommunityToolkit.Diagnostics;
+using LibCpp2IL.Metadata;
+using LibCpp2IL.Reflection;
 using LibProtodec.Models;
 using LibProtodec.Models.Fields;
 using LibProtodec.Models.TopLevels;
@@ -20,13 +22,12 @@ using LibProtodec.Models.Types;
 
 namespace LibProtodec;
 
-public delegate bool TypeLookupFunc(Type type, [NotNullWhen(true)] out IType? fieldType, out string? import);
+public delegate bool TypeLookupFunc(Il2CppTypeDefinition type, [NotNullWhen(true)] out IType? fieldType, out string? import);
 public delegate bool NameLookupFunc(string name, [MaybeNullWhen(false)] out string translatedName);
 
 public sealed class ProtodecContext
 {
-    private const BindingFlags PublicStatic           = BindingFlags.Public | BindingFlags.Static;
-    private const BindingFlags PublicInstanceDeclared = BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly;
+    private const FieldAttributes PublicStaticLiteral = FieldAttributes.Public | FieldAttributes.Static | FieldAttributes.Literal;
 
     private readonly Dictionary<string, TopLevel> _parsed = [];
 
@@ -52,11 +53,11 @@ public sealed class ProtodecContext
         }
     }
 
-    public Message ParseMessage(Type messageClass, ParserOptions options = ParserOptions.None)
+    public Message ParseMessage(Il2CppTypeDefinition messageClass, ParserOptions options = ParserOptions.None)
     {
-        Guard.IsTrue(messageClass is { IsClass: true, IsSealed: true });
+        Guard.IsTrue(messageClass.IsClass() && messageClass.IsSealed());
 
-        if (_parsed.TryGetValue(messageClass.FullName ?? messageClass.Name, out TopLevel? parsedMessage))
+        if (_parsed.TryGetValue(messageClass.FullName!, out TopLevel? parsedMessage))
         {
             return (Message)parsedMessage;
         }
@@ -64,50 +65,51 @@ public sealed class ProtodecContext
         Message message = new()
         {
             Name       = TranslateTypeName(messageClass),
-            IsObsolete = HasObsoleteAttribute(messageClass.GetCustomAttributesData())
+            IsObsolete = HasObsoleteAttribute(messageClass.GetCustomAttributeTypes())
         };
-        _parsed.Add(messageClass.FullName ?? messageClass.Name, message);
+        _parsed.Add(messageClass.FullName!, message);
 
         Protobuf protobuf = GetProtobuf(messageClass, message, options);
 
-        FieldInfo[]    idFields   = messageClass.GetFields(PublicStatic);
-        PropertyInfo[] properties = messageClass.GetProperties(PublicInstanceDeclared);
+        List<Il2CppFieldDefinition> idFields   = messageClass.GetFields(PublicStaticLiteral).ToList();
+        Il2CppPropertyDefinition[]  properties = messageClass.Properties!;
 
-        for (int pi = 0, fi = 0; pi < properties.Length; pi++, fi++)
+        for (int pi = 0, fi = 0; pi < properties.Length; pi++)
         {
-            PropertyInfo               property   = properties[pi];
-            IList<CustomAttributeData> attributes = property.GetCustomAttributesData();
-
-            if (((options & ParserOptions.IncludePropertiesWithoutNonUserCodeAttribute) == 0 && !HasNonUserCodeAttribute(attributes))
-             || property.GetMethod?.IsVirtual != false)
+            Il2CppPropertyDefinition property = properties[pi];
+            if (!property.CanRead()
+             || property.Getter!.IsStatic
+             || property.Getter!.IsVirtual()
+             || property.Getter!.IsNonPublic())
             {
-                fi--;
                 continue;
             }
 
-            Type propertyType = property.PropertyType;
+            List<Il2CppTypeDefinition> attributes = property.GetCustomAttributeTypes().ToList();
+            if (((options & ParserOptions.IncludePropertiesWithoutNonUserCodeAttribute) == 0 && !HasNonUserCodeAttribute(attributes)))
+            {
+                continue;
+            }
+
+            Il2CppTypeDefinition propertyType = property.PropertyType!.baseType!;
 
             // only OneOf enums are defined nested directly in the message class
-            if (propertyType.IsEnum && propertyType.DeclaringType?.Name == messageClass.Name)
+            if (propertyType.IsEnumType && propertyType.DeclaringType?.Name == messageClass.Name)
             {
-                string oneOfName = TranslateOneOfPropName(property.Name);
-                int[] oneOfProtoFieldIds = propertyType.GetFields(PublicStatic)
-                                                       .Select(static field => (int)field.GetRawConstantValue()!)
-                                                       .Where(static id => id > 0)
-                                                       .ToArray();
+                string oneOfName = TranslateOneOfPropName(property.Name!);
+                List<int> oneOfProtoFieldIds = propertyType.GetFields(PublicStaticLiteral)
+                                                           .Select(static field => (int)field.DefaultValue!.Value!)
+                                                           .Where(static id => id > 0)
+                                                           .ToList();
 
                 message.OneOfs.Add(oneOfName, oneOfProtoFieldIds);
-                
-                fi--;
                 continue;
             }
 
-            FieldInfo idField = idFields[fi];
-            Guard.IsTrue(idField.IsLiteral);
-            Guard.IsEqualTo(idField.FieldType.Name, nameof(Int32));
+            Il2CppFieldDefinition idField = idFields[fi];
 
             bool msgFieldHasHasProp = false; // some field properties are immediately followed by an additional "Has" get-only boolean property
-            if (properties.Length > pi + 1 && properties[pi + 1].PropertyType.Name == nameof(Boolean) && !properties[pi + 1].CanWrite)
+            if (properties.Length > pi + 1 && properties[pi + 1].PropertyType!.baseType!.Name == nameof(Boolean) && !properties[pi + 1].CanWrite())
             {
                 msgFieldHasHasProp = true;
                 pi++;
@@ -115,45 +117,46 @@ public sealed class ProtodecContext
 
             MessageField field = new()
             {
-                Type       = ParseFieldType(propertyType, options, protobuf),
-                Name       = TranslateMessageFieldName(property.Name),
-                Id         = (int)idField.GetRawConstantValue()!,
+                Type       = ParseFieldType(property.PropertyType!, options, protobuf),
+                Name       = TranslateMessageFieldName(property.Name!),
+                Id         = (int)idField.DefaultValue!.Value!,
                 IsObsolete = HasObsoleteAttribute(attributes),
                 HasHasProp = msgFieldHasHasProp
             };
 
             message.Fields.Add(field.Id, field);
+            fi++;
         }
 
         return message;
     }
 
-    public Enum ParseEnum(Type enumEnum, ParserOptions options = ParserOptions.None)
+    public Enum ParseEnum(Il2CppTypeDefinition enumEnum, ParserOptions options = ParserOptions.None)
     {
-        Guard.IsTrue(enumEnum.IsEnum);
+        Guard.IsTrue(enumEnum.IsEnumType);
 
-        if (_parsed.TryGetValue(enumEnum.FullName ?? enumEnum.Name, out TopLevel? parsedEnum))
+        if (_parsed.TryGetValue(enumEnum.FullName!, out TopLevel? parsedEnum))
         {
             return (Enum)parsedEnum;
         }
 
         Enum @enum = new()
         {
-            Name         = TranslateTypeName(enumEnum),
-            IsObsolete   = HasObsoleteAttribute(enumEnum.GetCustomAttributesData())
+            Name       = TranslateTypeName(enumEnum),
+            IsObsolete = HasObsoleteAttribute(enumEnum.GetCustomAttributeTypes())
         };
-        _parsed.Add(enumEnum.FullName ?? enumEnum.Name, @enum);
+        _parsed.Add(enumEnum.FullName!, @enum);
 
         Protobuf protobuf = GetProtobuf(enumEnum, @enum, options);
 
-        foreach (FieldInfo field in enumEnum.GetFields(PublicStatic))
+        foreach (Il2CppFieldDefinition field in enumEnum.GetFields(PublicStaticLiteral))
         {
             @enum.Fields.Add(
                 new EnumField
                 {
-                    Id         = (int)field.GetRawConstantValue()!,
-                    Name       = TranslateEnumFieldName(field, @enum.Name),
-                    IsObsolete = HasObsoleteAttribute(field.GetCustomAttributesData())
+                    Id         = (int)field.DefaultValue!.Value!,
+                    Name       = TranslateEnumFieldName(field.Name!, @enum.Name),
+                    IsObsolete = HasObsoleteAttribute(field.GetCustomAttributeTypes())
                 });
         }
 
@@ -166,34 +169,34 @@ public sealed class ProtodecContext
         return @enum;
     }
 
-    public Service ParseService(Type serviceClass, ParserOptions options = ParserOptions.None)
+    public Service ParseService(Il2CppTypeDefinition serviceClass, ParserOptions options = ParserOptions.None)
     {
-        Guard.IsTrue(serviceClass.IsClass);
+        Guard.IsTrue(serviceClass.IsClass());
 
         bool? isClientClass = null;
         if (serviceClass.IsAbstract)
         {
-            if (serviceClass is { IsSealed: true, IsNested: false })
+            if (serviceClass.IsSealed() && !serviceClass.IsNested())
             {
-                Type[] nested = serviceClass.GetNestedTypes();
-                serviceClass  = nested.SingleOrDefault(static nested => nested is { IsAbstract: true, IsSealed: false })
-                             ?? nested.Single(static nested => nested is { IsClass: true, IsAbstract: false });
+                Il2CppTypeDefinition[] nested = serviceClass.NestedTypes!;
+                serviceClass = nested.SingleOrDefault(static nested => nested.IsAbstract && !nested.IsSealed())
+                            ?? nested.Single(static nested => nested.IsClass() && !nested.IsAbstract);
             }
             
-            if (serviceClass is { IsNested: true, IsAbstract: true, IsSealed: false })
+            if (serviceClass.IsNested() && serviceClass.IsAbstract && !serviceClass.IsSealed())
             {
                 isClientClass = false;
             }
         }
 
-        if (serviceClass is { IsAbstract: false, IsNested: true, DeclaringType: not null })
+        if (serviceClass is { IsAbstract: false, DeclaringType: not null })
         {
             isClientClass = true;
         }
 
         Guard.IsNotNull(isClientClass);
 
-        if (_parsed.TryGetValue(serviceClass.DeclaringType!.FullName ?? serviceClass.DeclaringType!.Name, out TopLevel? parsedService))
+        if (_parsed.TryGetValue(serviceClass.DeclaringType!.FullName!, out TopLevel? parsedService))
         {
             return (Service)parsedService;
         }
@@ -201,50 +204,54 @@ public sealed class ProtodecContext
         Service service = new()
         {
             Name         = TranslateTypeName(serviceClass.DeclaringType),
-            IsObsolete   = HasObsoleteAttribute(serviceClass.GetCustomAttributesData())
+            IsObsolete   = HasObsoleteAttribute(serviceClass.GetCustomAttributeTypes())
         };
-        _parsed.Add(serviceClass.DeclaringType!.FullName ?? serviceClass.DeclaringType.Name, service);
+        _parsed.Add(serviceClass.DeclaringType!.FullName!, service);
 
         Protobuf protobuf = NewProtobuf(serviceClass, service);
 
-        foreach (MethodInfo method in serviceClass.GetMethods(PublicInstanceDeclared))
+        foreach (Il2CppMethodDefinition method in serviceClass.Methods!)
         {
-            IList<CustomAttributeData> attributes = method.GetCustomAttributesData();
+            if (method.IsNonPublic() || method.IsStatic)
+            {
+                continue;
+            }
+
+            List<Il2CppTypeDefinition> attributes = method.GetCustomAttributeTypes().ToList();
             if ((options & ParserOptions.IncludeServiceMethodsWithoutGeneratedCodeAttribute) == 0
              && !HasGeneratedCodeAttribute(attributes, "grpc_csharp_plugin"))
             {
                 continue;
             }
 
-            Type requestType, responseType, returnType = method.ReturnType;
-            bool streamReq,   streamRes;
+            Il2CppTypeReflectionData requestType, responseType, returnType = method.ReturnType!;
+            bool streamReq, streamRes;
 
             if (isClientClass.Value)
             {
-                string returnTypeName = TranslateTypeName(returnType);
+                string returnTypeName = TranslateTypeName(returnType.baseType!);
                 if (returnTypeName == "AsyncUnaryCall`1")
                 {
                     continue;
                 }
 
-                ParameterInfo[] parameters = method.GetParameters();
-                if (parameters.Length > 2)
+                if (method.Parameters!.Length > 2)
                 {
                     continue;
                 }
 
-                Type firstParamType = parameters[0].ParameterType;
-                switch (returnType.GenericTypeArguments.Length)
+                Il2CppTypeReflectionData firstParamType = method.Parameters![0].Type;
+                switch (returnType.genericParams.Length)
                 {
                     case 2:
-                        requestType  = returnType.GenericTypeArguments[0];
-                        responseType = returnType.GenericTypeArguments[1];
+                        requestType  = returnType.genericParams[0];
+                        responseType = returnType.genericParams[1];
                         streamReq    = true;
                         streamRes    = returnTypeName == "AsyncDuplexStreamingCall`2";
                         break;
                     case 1:
                         requestType  = firstParamType;
-                        responseType = returnType.GenericTypeArguments[0];
+                        responseType = returnType.genericParams[0];
                         streamReq    = false;
                         streamRes    = true;
                         break;
@@ -258,13 +265,11 @@ public sealed class ProtodecContext
             }
             else
             {
-                ParameterInfo[] parameters     = method.GetParameters();
-                Type            firstParamType = parameters[0].ParameterType;
-
-                if (firstParamType.GenericTypeArguments.Length == 1)
+                Il2CppTypeReflectionData firstParamType = method.Parameters![0].Type;
+                if (firstParamType.genericParams.Length == 1)
                 {
                     streamReq   = true;
-                    requestType = firstParamType.GenericTypeArguments[0];
+                    requestType = firstParamType.genericParams[0];
                 }
                 else
                 {
@@ -272,22 +277,22 @@ public sealed class ProtodecContext
                     requestType = firstParamType;
                 }
 
-                if (returnType.GenericTypeArguments.Length == 1)
+                if (returnType.genericParams.Length == 1)
                 {
                     streamRes    = false;
-                    responseType = returnType.GenericTypeArguments[0];
+                    responseType = returnType.genericParams[0];
                 }
                 else
                 {
                     streamRes    = true;
-                    responseType = parameters[1].ParameterType.GenericTypeArguments[0];
+                    responseType = method.Parameters![1].Type.genericParams[0];
                 }
             }
 
             service.Methods.Add(
                 new ServiceMethod
                 {
-                    Name               = TranslateMethodName(method.Name),
+                    Name               = TranslateMethodName(method.Name!),
                     IsObsolete         = HasObsoleteAttribute(attributes),
                     RequestType        = ParseFieldType(requestType,  options, protobuf),
                     ResponseType       = ParseFieldType(responseType, options, protobuf),
@@ -299,19 +304,21 @@ public sealed class ProtodecContext
         return service;
     }
 
-    private IType ParseFieldType(Type type, ParserOptions options, Protobuf referencingProtobuf)
+    private IType ParseFieldType(Il2CppTypeReflectionData reflectionData, ParserOptions options, Protobuf referencingProtobuf)
     {
-        switch (type.GenericTypeArguments.Length)
+        switch (reflectionData.genericParams.Length)
         {
             case 1:
                 return new Repeated(
-                    ParseFieldType(type.GenericTypeArguments[0], options, referencingProtobuf));
+                    ParseFieldType(reflectionData.genericParams[0], options, referencingProtobuf));
             case 2:
                 return new Map(
-                    ParseFieldType(type.GenericTypeArguments[0], options, referencingProtobuf),
-                    ParseFieldType(type.GenericTypeArguments[1], options, referencingProtobuf));
+                    ParseFieldType(reflectionData.genericParams[0], options, referencingProtobuf),
+                    ParseFieldType(reflectionData.genericParams[1], options, referencingProtobuf));
         }
 
+        Il2CppTypeDefinition type = reflectionData.baseType!;
+
         if (TypeLookup(type, out IType? fieldType, out string? import))
         {
             if (import is not null)
@@ -322,7 +329,7 @@ public sealed class ProtodecContext
             return fieldType;
         }
 
-        if (type.IsEnum)
+        if (type.IsEnumType)
         {
             if ((options & ParserOptions.SkipEnums) > 0)
             {
@@ -345,11 +352,11 @@ public sealed class ProtodecContext
         return fieldType;
     }
 
-    private Protobuf NewProtobuf(Type topLevelType, TopLevel topLevel)
+    private Protobuf NewProtobuf(Il2CppTypeDefinition topLevelType, TopLevel topLevel)
     {
         Protobuf protobuf = new()
         {
-            AssemblyName = topLevelType.Assembly.FullName,
+            AssemblyName = topLevelType.DeclaringAssembly!.Name!,
             Namespace    = topLevelType.Namespace
         };
 
@@ -360,14 +367,14 @@ public sealed class ProtodecContext
         return protobuf;
     }
 
-    private Protobuf GetProtobuf<T>(Type topLevelType, T topLevel, ParserOptions options)
+    private Protobuf GetProtobuf<T>(Il2CppTypeDefinition topLevelType, T topLevel, ParserOptions options)
         where T : TopLevel, INestableType
     {
         Protobuf protobuf;
-        if (topLevelType.IsNested)
+        if (topLevelType.IsNested())
         {
-            Type parent = topLevelType.DeclaringType!.DeclaringType!;
-            if (!_parsed.TryGetValue(parent.FullName ?? parent.Name, out TopLevel? parentTopLevel))
+            Il2CppTypeDefinition parent = topLevelType.DeclaringType!.DeclaringType!;
+            if (!_parsed.TryGetValue(parent.FullName!, out TopLevel? parentTopLevel))
             {
                 parentTopLevel = ParseMessage(parent, options);
             }
@@ -376,7 +383,7 @@ public sealed class ProtodecContext
             topLevel.Protobuf = protobuf;
             topLevel.Parent   = parentTopLevel;
 
-            ((Message)parentTopLevel).Nested.Add(topLevelType.Name, topLevel);
+            ((Message)parentTopLevel).Nested.Add(topLevelType.Name!, topLevel);
         }
         else
         {
@@ -421,25 +428,18 @@ public sealed class ProtodecContext
         return translatedName!.ToSnakeCaseLower();
     }
 
-    private string TranslateEnumFieldName(FieldInfo field, string enumName)
+    private string TranslateEnumFieldName(string fieldName, string enumName)
     {
-        if (field.GetCustomAttributesData()
-                 .SingleOrDefault(static attr => attr.AttributeType.Name == "OriginalNameAttribute")
-                ?.ConstructorArguments[0]
-                 .Value
-            is string originalName)
+        //TODO: parse original name from first parameter of OriginalNameAttribute constructor
+
+        if (NameLookup?.Invoke(fieldName, out string? translatedName) == true)
         {
-            return originalName;
+            fieldName = translatedName;
         }
 
-        if (NameLookup?.Invoke(field.Name, out string? fieldName) != true)
+        if (!IsBeebyted(fieldName))
         {
-            fieldName = field.Name;
-        }
-
-        if (!IsBeebyted(fieldName!))
-        {
-            fieldName = fieldName!.ToSnakeCaseUpper();
+            fieldName = fieldName.ToSnakeCaseUpper();
         }
 
         if (!IsBeebyted(enumName))
@@ -450,21 +450,19 @@ public sealed class ProtodecContext
         return enumName + '_' + fieldName;
     }
 
-    private string TranslateTypeName(Type type)
+    private string TranslateTypeName(Il2CppTypeDefinition type)
     {
         if (NameLookup is null)
-            return type.Name;
-
-        string? fullName = type.FullName;
-        Guard.IsNotNull(fullName);
+            return type.Name!;
 
+        string fullName = type.FullName!;
         int genericArgs = fullName.IndexOf('[');
         if (genericArgs != -1)
             fullName = fullName[..genericArgs];
 
         if (!NameLookup(fullName, out string? translatedName))
         {
-            return type.Name;
+            return type.Name!;
         }
 
         int lastSlash = translatedName.LastIndexOf('/');
@@ -478,7 +476,7 @@ public sealed class ProtodecContext
         return translatedName;
     }
 
-    public static bool LookupScalarAndWellKnownTypes(Type type, [NotNullWhen(true)] out IType? fieldType, out string? import)
+    public static bool LookupScalarAndWellKnownTypes(Il2CppTypeDefinition type, [NotNullWhen(true)] out IType? fieldType, out string? import)
     {
         switch (type.FullName)
         {
@@ -642,13 +640,15 @@ public sealed class ProtodecContext
     private static bool IsBeebyted(string name) =>
         name.Length == 11 && name.CountUpper() == 11;
 
-    private static bool HasGeneratedCodeAttribute(IEnumerable<CustomAttributeData> attributes, string tool) =>
-        attributes.Any(attr => attr.AttributeType.Name                      == nameof(GeneratedCodeAttribute)
-                            && attr.ConstructorArguments[0].Value as string == tool);
+    private static bool HasGeneratedCodeAttribute(IEnumerable<Il2CppTypeDefinition> attributeTypes, string tool)
+    {
+        return attributeTypes.Any(static attrType => attrType.Name == nameof(GeneratedCodeAttribute));
+        //TODO: ensure the first argument of the GeneratedCodeAttribute constructor == tool parameter
+    }
 
-    private static bool HasNonUserCodeAttribute(IEnumerable<CustomAttributeData> attributes) =>
-        attributes.Any(static attr => attr.AttributeType.Name == nameof(DebuggerNonUserCodeAttribute));
+    private static bool HasNonUserCodeAttribute(IEnumerable<Il2CppTypeDefinition> attributeTypes) =>
+        attributeTypes.Any(static attrType => attrType.Name == nameof(DebuggerNonUserCodeAttribute));
 
-    private static bool HasObsoleteAttribute(IEnumerable<CustomAttributeData> attributes) =>
-        attributes.Any(static attr => attr.AttributeType.Name == nameof(ObsoleteAttribute));
+    private static bool HasObsoleteAttribute(IEnumerable<Il2CppTypeDefinition> attributeTypes) =>
+        attributeTypes.Any(static attrType => attrType.Name == nameof(ObsoleteAttribute));
 }

src/protodec/Program.cs

@@ -3,14 +3,18 @@ using System.CodeDom.Compiler;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using AssetRipper.Primitives;
+using LibCpp2IL.Metadata;
 using LibProtodec;
 using LibProtodec.Models;
 
 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.
       out_path              An existing directory to output into individual files, otherwise output to a single file.
     Options:
       --parse_service_servers                                     Parses gRPC service definitions from server classes.
@@ -20,14 +24,16 @@ 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];
+UnityVersion  uVersion = UnityVersion.Parse(args[2]);
+string        outPath  = Path.GetFullPath(args[3]);
 ParserOptions options  = ParserOptions.None;
 
 if (args.Contains("--skip_enums"))
@@ -39,17 +45,17 @@ if (args.Contains("--include_properties_without_non_user_code_attribute"))
 if (args.Contains("--include_service_methods_without_generated_code_attribute"))
     options |= ParserOptions.IncludeServiceMethodsWithoutGeneratedCodeAttribute;
 
-using AssemblyInspector inspector = new(assembly);
+using Il2CppLoader inspector = new(assembly, metadata, uVersion);
 ProtodecContext ctx = new();
 
-foreach (Type message in inspector.GetProtobufMessageTypes())
+foreach (Il2CppTypeDefinition message in inspector.GetProtobufMessageTypes())
 {
     ctx.ParseMessage(message, options);
 }
 
 if (args.Contains("--parse_service_servers"))
 {
-    foreach (Type service in inspector.GetProtobufServiceServerTypes())
+    foreach (Il2CppTypeDefinition service in inspector.GetProtobufServiceServerTypes())
     {
         ctx.ParseService(service, options);
     }
@@ -57,7 +63,7 @@ if (args.Contains("--parse_service_servers"))
 
 if (args.Contains("--parse_service_clients"))
 {
-    foreach (Type service in inspector.GetProtobufServiceClientTypes())
+    foreach (Il2CppTypeDefinition service in inspector.GetProtobufServiceClientTypes())
     {
         ctx.ParseService(service, options);
     }