Formats: Add option for multiple load strategies per sub-image

Il2CppInspector.Common/FileFormatReaders/FileFormatReader.cs

@@ -21,15 +21,16 @@ namespace Il2CppInspector
         long Length { get; }
         uint NumImages { get; }
         string DefaultFilename { get; }
-        bool IsModified { get; }
+        bool IsModified { get; } 
-        IEnumerable<IFileFormatReader> Images { get; }
+        IEnumerable<IFileFormatReader> Images { get; } // Each child image of this object (eg. 32/64-bit versions in Fat MachO file)
-        IFileFormatReader this[uint index] { get; }
+        IFileFormatReader this[uint index] { get; } // With no additional override, one object = one file, this[0] == this
         long Position { get; set; }
         string Format { get; }
         string Arch { get; }
         int Bits { get; }
         ulong GlobalOffset { get; } // The virtual address where the code section (.text) would be loaded in memory
         ulong ImageBase { get; } // The virtual address of where the image would be loaded in memory (same as GlobalOffset except for PE)
+        IEnumerable<IFileFormatReader> TryNextLoadStrategy(); // Some images can be loaded multiple ways, eg. default, packed
         Dictionary<string, Symbol> GetSymbolTable();
         uint[] GetFunctionTable();
         IEnumerable<Export> GetExports();
@@ -184,9 +185,12 @@ namespace Il2CppInspector
         // Confirm file is valid and set up RVA mappings
         protected virtual bool Init() => throw new NotImplementedException();
 
-        // Choose a sub-binary within the image for multi-architecture binaries
+        // Choose an image within the file for multi-architecture binaries
         public virtual IFileFormatReader this[uint index] => (index == 0)? this : throw new IndexOutOfRangeException("Binary image index out of bounds");
 
+        // For images that can be loaded and then tested with Il2CppBinary in multiple ways, get the next possible version of the image
+        public virtual IEnumerable<IFileFormatReader> TryNextLoadStrategy() { yield return this; }
+
         // Find search locations in the symbol table for Il2Cpp data
         public virtual Dictionary<string, Symbol> GetSymbolTable() => new Dictionary<string, Symbol>();
 

Il2CppInspector.Common/IL2CPP/Il2CppBinary.cs

@@ -95,12 +95,16 @@ namespace Il2CppInspector
         protected Il2CppBinary(IFileFormatReader stream, EventHandler<string> statusCallback = null) {
             Image = stream;
             OnStatusUpdate = statusCallback;
+
+            StatusUpdate($"Analyzing IL2CPP data for {Image.Format}/{Image.Arch} image");
             DiscoverAPIExports();
         }
 
         protected Il2CppBinary(IFileFormatReader stream, uint codeRegistration, uint metadataRegistration, EventHandler<string> statusCallback = null) {
             Image = stream;
             OnStatusUpdate = statusCallback;
+
+            StatusUpdate($"Analyzing IL2CPP data for {Image.Format}/{Image.Arch} image");
             DiscoverAPIExports();
             PrepareMetadata(codeRegistration, metadataRegistration);
         }
@@ -123,8 +127,12 @@ namespace Il2CppInspector
 
         // Load binary without a global-metadata.dat available
         public static Il2CppBinary Load(IFileFormatReader stream, double metadataVersion, EventHandler<string> statusCallback = null) {
-            var inst = LoadImpl(stream, statusCallback);
+            foreach (var loadedImage in stream.TryNextLoadStrategy()) {
-            return inst.FindRegistrationStructs(metadataVersion) ? inst : null;
+                var inst = LoadImpl(stream, statusCallback);
+                if (inst.FindRegistrationStructs(metadataVersion))
+                    return inst;
+            }
+            return null;
         }
 
         // Load binary with a global-metadata.dat available
@@ -133,8 +141,12 @@ namespace Il2CppInspector
         // Metadata will be used to try to find the required structures with data analysis
         // If it is not specified, data analysis will not be performed
         public static Il2CppBinary Load(IFileFormatReader stream, Metadata metadata, EventHandler<string> statusCallback = null) {
-            var inst = LoadImpl(stream, statusCallback);
+            foreach (var loadedImage in stream.TryNextLoadStrategy()) {
-            return inst.FindRegistrationStructs(metadata) ? inst : null;
+                var inst = LoadImpl(stream, statusCallback);
+                if (inst.FindRegistrationStructs(metadata))
+                    return inst;
+            }
+            return null;
         }
 
         // Save binary to file, overwriting if necessary
@@ -146,24 +158,24 @@ namespace Il2CppInspector
         }
 
         // Initialize binary without a global-metadata.dat available
-        public bool FindRegistrationStructs(double metadataVersion, EventHandler<string> statusCallback = null) {
+        public bool FindRegistrationStructs(double metadataVersion) {
             Image.Version = metadataVersion;
 
-            if (!((FindMetadataFromSymbols() ?? FindMetadataFromCode()) is var ptrs))
+            if (!((FindMetadataFromSymbols() ?? FindMetadataFromCode()) is (ulong code, ulong meta)))
                 return false;
 
-            PrepareMetadata(ptrs.Value.Item1, ptrs.Value.Item2);
+            PrepareMetadata(code, meta);
             return true;
         }
 
         // Initialize binary with a global-metadata.dat available
-        public bool FindRegistrationStructs(Metadata metadata, EventHandler<string> statusCallback = null) {
+        public bool FindRegistrationStructs(Metadata metadata) {
             Image.Version = metadata.Version;
 
-            if (!((FindMetadataFromSymbols() ?? FindMetadataFromCode() ?? FindMetadataFromData(metadata)) is var ptrs))
+            if (!((FindMetadataFromSymbols() ?? FindMetadataFromCode() ?? FindMetadataFromData(metadata)) is (ulong code, ulong meta)))
                 return false;
 
-            PrepareMetadata(ptrs.Value.Item1, ptrs.Value.Item2, metadata);
+            PrepareMetadata(code, meta);
             return true;
         }
 

Il2CppInspector.GUI/App.xaml.cs

@@ -124,8 +124,6 @@ namespace Il2CppInspectorGUI
                     // Multi-image binaries may contain more than one Il2Cpp image
                     AppModels.Clear();
                     foreach (var image in stream.Images) {
-                        OnStatusUpdate?.Invoke(this, $"Analyzing IL2CPP data for {image.Format}/{image.Arch} image");
-
                         // Architecture-agnostic load attempt
                         try {
                             // If we can't load the IL2CPP data here, it's probably packed or obfuscated; ignore it