IL2CPP: Encoded tokens in metadata v27 must be shifted right 1 bit

Il2CppInspector.Common/IL2CPP/Il2CppInspector.cs

@@ -127,9 +127,17 @@ namespace Il2CppInspector
             return ((ulong) pValue, value);
         }
 
-        // TODO: The resolution of metadata usages is broken for metadata v27 (MetadataUsageLists, MetadataUsagePairs no longer exist)
         private List<MetadataUsage> buildMetadataUsages()
         {
+            // No metadata usages for versions < 19
+            if (Version < 19)
+                return null;
+
+            // Metadata usages are lazily initialized during runtime for versions >= 27
+            if (Version >= 27)
+                return buildLateBindingMetadataUsages();
+
+            // Version >= 19 && <= 24.3
             var usages = new Dictionary<uint, MetadataUsage>();
             foreach (var metadataUsageList in Metadata.MetadataUsageLists)
             {
@@ -150,6 +158,11 @@ namespace Il2CppInspector
             return usages.Values.ToList();
         }
 
+        public List<MetadataUsage> buildLateBindingMetadataUsages() {
+            // TODO: Resolve late binding for metadata v27
+            return null;
+        }
+
         public Il2CppInspector(Il2CppBinary binary, Metadata metadata) {
             // Store stream representations
             Binary = binary;
@@ -243,7 +256,6 @@ namespace Il2CppInspector
             }
 
             // Merge all metadata usage references into a single distinct list
-            if (Version >= 19)
             MetadataUsages = buildMetadataUsages();
         }
 

Il2CppInspector.Common/IL2CPP/MetadataUsage.cs

@@ -42,6 +42,10 @@ namespace Il2CppInspector
                 var encodedType = encodedIndex & 0xE0000000;
                 usageType = (MetadataUsageType)(encodedType >> 29);
                 index = encodedIndex & 0x1FFFFFFF;
+
+                // From v27 the bottom bit is set to indicate the usage token hasn't been replaced with a pointer at runtime yet
+                if (package.Version >= 27)
+                    index >>= 1;
             }
             return new MetadataUsage(usageType, (int)index);
         }

Il2CppInspector.Common/Model/AppModel.cs

@@ -51,7 +51,7 @@ namespace Il2CppInspector.Model
         // For il2cpp < 19, the key is the string literal ordinal instead of the address
         public Dictionary<ulong, string> Strings { get; } = new Dictionary<ulong, string>();
 
-        public bool StringIndexesAreOrdinals => Package.MetadataUsages == null;
+        public bool StringIndexesAreOrdinals => Package.Version < 19;
 
         // The .NET type model for the application
         public TypeModel TypeModel { get; }
@@ -239,7 +239,7 @@ namespace Il2CppInspector.Model
                 }
 
             // Add string literals for metadata <19 to the model
-            else {
+            if (Package.Version < 19) {
                 /* Version < 19 calls `il2cpp_codegen_string_literal_from_index` to get string literals.
                  * Unfortunately, metadata references are just loose globals in Il2CppMetadataUsage.cpp
                  * so we can't automatically name those. Next best thing is to define an enum for the strings. */