Transforms .NET DLLs for use in AOT (for use on iOS platforms, including Unity3D.) Fixes Unity's .NET 3.5 event add/remove code and a workaround for generic virtual methods.

My status: This tool only addresses some of the issues in AOT compatibility. Unfortunately, despite putting in a lot of time, I have not been able to successfully port all of my own codebase to Unity3D's Mono. There are issues with generic interface dispatch, including calls to foreach(IEnumerable<T>). I like generic interfaces and foreach and have a lot of both, so I appear to be somewhat doomed until I can make a comprehensive sweep of my codebase (and hope I have covered all the issues, which is still a gamble.)

So, I have put my iOS project on hold and am instead targeting PC (a non-Unity3D project), Mac, and Android first. Perhaps by then Unity3D will have a newer version of mono that is less broken, or perhaps another viable cross platform C# engine will exist by then.

Mono.Cecil.dll (DLL version 0.9.4.0, from package Cecil 2.10.9)

To the extent possible under law, Jared Thirsk has waived all copyright and related or neighboring rights to AOT-Compatlyzer. This work is published from: Canada.

(Note: contributions are welcome, of course!)

Bringing a .NET codebase onto iOS via Mono? (Perhaps via Unity3D?) This tool can help ease the pain!

Unity 3.5 (and I believe 4) ships with a modified version of Mono 2.6.5 that spits out Interlocked.CompareExchange<>() virtual methods inside of auto-generated add_/remove_ properties for C# events. This is a problem in AOT code. AOT-Compatlyzer replaces this autogenerated code with a version that uses an alternate implementation.

WARNING: Currently, I do not add the Synchronized attribute to the new add_/remove_ methods, which should be present, according to the example code I was working from.

UPDATE: There is a better fix that preserves thread safety, using the version of CompareExchange/Exchange that accepts parameters of objects instead of value types. For details see Issue 1

AOT does not support virtual methods.

AOTCompatlyzer introduces some workarounds for some scenarios:

#define AOT   // Comment this to hide code only needed for AOT-only mode

class Abc 
{
    // Compiles, but throws ExecutionEngineException in AOT-only mode if invoked!
    T MyMethod<T>(int p1, int p2) { …  }

#if AOT // AOTCompatlyzer will detect and use this instead!
    object MyMethod(int p1, int p2, Type T) { …  }
#endif

    void Run()
    {
        ...
        T myObj = MyMethod<T>(1, 2);
        ...
    }
}

AOTCopatlyzer will replace Run's MyMethod invocation with:

void Run() //
{
    ...
    T myObj = (T) MyMethod(1, 2, typeof(T));
    ...
}

These cases are also supported:

• both methods return void
• both method return same type (in this case, casting to T is not necessary).

• Only one generic parameter is supported: i.e. MyMethod<T> and not MyMethod<T1,T2>. (TODO: This could be easily supported.)

I am not finished porting my codebase to an AOT-only environment yet. As I run into more problems I will either adapt my codebase, or extend this utility to morph my DLL to something that works in AOT-only mode.

• I believe Action<T1,T2> events fail.