From 7f0f5121e42117d6ac448536a435a0463e5d2bc5 Mon Sep 17 00:00:00 2001
From: Katy Coe <djkaty@start.no>
Date: Tue, 5 Nov 2019 16:21:25 +0100
Subject: [PATCH] Model: Enumerations have an underlying type, not an element
 type

---
 Il2CppDumper/Il2CppCSharpDumper.cs     |  4 +--
 Il2CppInspector/Reflection/TypeInfo.cs | 34 ++++++++++++--------------
 2 files changed, 18 insertions(+), 20 deletions(-)

diff --git a/Il2CppDumper/Il2CppCSharpDumper.cs b/Il2CppDumper/Il2CppCSharpDumper.cs
index a747240..2c5eb81 100644
--- a/Il2CppDumper/Il2CppCSharpDumper.cs
+++ b/Il2CppDumper/Il2CppCSharpDumper.cs
@@ -128,8 +128,8 @@ namespace Il2CppInspector
             var @base = type.ImplementedInterfaces.Select(x => x.CSharpName).ToList();
             if (type.BaseType != null && type.BaseType.FullName != "System.Object" && type.BaseType.FullName != "System.ValueType" && !type.IsEnum)
                 @base.Insert(0, type.BaseType.CSharpName);
-            if (type.IsEnum && type.ElementType.CSharpName != "int") // enums derive from int by default
-                @base.Insert(0, type.ElementType.CSharpName);
+            if (type.IsEnum && type.GetEnumUnderlyingType().FullName != "System.Int32") // enums derive from int by default
+                @base.Insert(0, type.GetEnumUnderlyingType().CSharpName);
             var baseText = @base.Count > 0 ? " : " + string.Join(", ", @base) : string.Empty;
 
             writer.Write($"{type.CSharpTypeDeclarationName}{baseText} // TypeDefIndex: {type.Index}\n" + prefix + "{\n");
diff --git a/Il2CppInspector/Reflection/TypeInfo.cs b/Il2CppInspector/Reflection/TypeInfo.cs
index d010b87..4a1bf55 100644
--- a/Il2CppInspector/Reflection/TypeInfo.cs
+++ b/Il2CppInspector/Reflection/TypeInfo.cs
@@ -93,16 +93,7 @@ namespace Il2CppInspector.Reflection {
         public bool IsGenericMethodParameter => IsGenericParameter && DeclaringMethod != null;
 
         // Gets the type of the object encompassed or referred to by the current array, pointer or reference type
-        private readonly int enumElementTypeUsage;
-
-        private TypeInfo elementType;
-        public TypeInfo ElementType {
-            get {
-                if (IsEnum && elementType == null)
-                    elementType = Assembly.Model.GetTypeFromUsage(enumElementTypeUsage, MemberTypes.TypeInfo);
-                return elementType;
-            }
-        }
+        public TypeInfo ElementType { get; }
 
         // Type name including namespace
         public string FullName =>
@@ -129,7 +120,7 @@ namespace Il2CppInspector.Reflection {
         public bool IsArray { get; }
         public bool IsByRef => throw new NotImplementedException();
         public bool IsClass => (Attributes & TypeAttributes.ClassSemanticsMask) == TypeAttributes.Class;
-        public bool IsEnum { get; }
+        public bool IsEnum => enumUnderlyingTypeUsage != -1;
         public bool IsGenericParameter { get; }
         public bool IsGenericType { get; }
         public bool IsGenericTypeDefinition { get; }
@@ -167,7 +158,16 @@ namespace Il2CppInspector.Reflection {
 
         public string[] GetEnumNames() => IsEnum? DeclaredFields.Where(x => x.Name != "value__").Select(x => x.Name).ToArray() : throw new InvalidOperationException("Type is not an enumeration");
 
-        public TypeInfo GetEnumUnderlyingType() => ElementType;
+        // The underlying type of an enumeration (int by default)
+        private readonly int enumUnderlyingTypeUsage = -1;
+        private TypeInfo enumUnderlyingType;
+
+        public TypeInfo GetEnumUnderlyingType() {
+            if (!IsEnum)
+                return null;
+            enumUnderlyingType ??= Assembly.Model.GetTypeFromUsage(enumUnderlyingTypeUsage, MemberTypes.TypeInfo);
+            return enumUnderlyingType;
+        }
 
         public Array GetEnumValues() => IsEnum? DeclaredFields.Where(x => x.Name != "value__").Select(x => x.DefaultValue).ToArray() : throw new InvalidOperationException("Type is not an enumeration");
 
@@ -242,10 +242,8 @@ namespace Il2CppInspector.Reflection {
                 Attributes |= TypeAttributes.Interface;
 
             // Enumerations - bit 1 of bitfield indicates this (also the baseTypeUsage will be System.Enum)
-            if (((Definition.bitfield >> 1) & 1) == 1) {
-                IsEnum = true;
-                enumElementTypeUsage = Definition.elementTypeIndex;
-            }
+            if (((Definition.bitfield >> 1) & 1) == 1)
+                enumUnderlyingTypeUsage = Definition.elementTypeIndex;
 
             // Add all implemented interfaces
             implementedInterfaceUsages = new int[Definition.interfaces_count];
@@ -334,7 +332,7 @@ namespace Il2CppInspector.Reflection {
             // Array with known dimensions and bounds
             if (pType.type == Il2CppTypeEnum.IL2CPP_TYPE_ARRAY) {
                 var descriptor = image.ReadMappedObject<Il2CppArrayType>(pType.datapoint);
-                elementType = model.GetTypeFromVirtualAddress(descriptor.etype);
+                ElementType = model.GetTypeFromVirtualAddress(descriptor.etype);
 
                 Assembly = ElementType.Assembly;
                 Definition = ElementType.Definition;
@@ -348,7 +346,7 @@ namespace Il2CppInspector.Reflection {
 
             // Dynamically allocated array or pointer type
             if (pType.type == Il2CppTypeEnum.IL2CPP_TYPE_SZARRAY || pType.type == Il2CppTypeEnum.IL2CPP_TYPE_PTR) {
-                elementType = model.GetTypeFromVirtualAddress(pType.datapoint);
+                ElementType = model.GetTypeFromVirtualAddress(pType.datapoint);
 
                 Assembly = ElementType.Assembly;
                 Definition = ElementType.Definition;