Detect backend (IL2CPP) or JIT support at runtime

Hi! I have code that works differently whether JIT is available. Basically, it will get optimized if JIT is available.

Up until Unity 2018.1, I used this code to check at runtime whether JIT was supported:

Code (CSharp):

1. public static bool SupportsJit(this RuntimePlatform platform)
2. {
3.     return
4.         platform == RuntimePlatform.WindowsEditor ||
5.         platform == RuntimePlatform.WindowsPlayer ||
6.         platform == RuntimePlatform.OSXEditor ||
7.         platform == RuntimePlatform.OSXPlayer ||
8.         platform == RuntimePlatform.LinuxEditor ||
9.         platform == RuntimePlatform.LinuxPlayer;
10. }
11.  

However now that Standalone builds support an IL2CPP backend, it means JIT might not be available on those. But I can't seem to find any way of checking which backend is currently being used (or if JIT is supported) at runtime.

Note that:

• I can't check this in the editor, it has to be at runtime
• I can't use script defines (#if ...) because I'm shipping my code as a DLL

Am I missing an API method? How can I go about this?

 

Bump?

 

Hrmm... I don't know if anything exists directly.

But this does intrigue me. If anyone else knows, please share.

With that said, tomorrow when I get up I may look into this if I have a spare moment during the day. If one doesn't exist, I'm willing to bet you could cheat a method of determining it. Like maybe attempting to exploit a JIT only feature (maybe emit, implicit generics, or something else?), and if it fails consider yourself in a non-JIT situation and flag some static bool so you only test it once.

 

Here's my attempt with the try-catch method. It seems to work, but it's a bit hacky:

Code (CSharp):

1. using System;
2. using System.Reflection;
3. using System.Reflection.Emit;
4. using UnityEngine;
5.  
6. namespace Ludiq
7. {
8.     public static class PlatformUtility
9.     {
10.         public static readonly bool supportsJit;
11.  
12.         static PlatformUtility()
13.         {
14.             var isStandalone = Application.platform.IsStandalone();
15.  
16.             if (isStandalone)
17.             {
18.                 try
19.                 {
20.                     AppDomain.CurrentDomain.DefineDynamicAssembly(new AssemblyName("EmitCompatibilityCheck"), AssemblyBuilderAccess.Save);
21.                     supportsJit = true;
22.                 }
23.                 catch (Exception)
24.                 {
25.                     Debug.Log("JIT has been disabled on this standalone build.");
26.                 }
27.             }
28.         }
29.        
30.         public static bool IsStandalone(this RuntimePlatform platform)
31.         {
32.             return
33.                 platform == RuntimePlatform.WindowsEditor ||
34.                 platform == RuntimePlatform.WindowsPlayer ||
35.                 platform == RuntimePlatform.OSXEditor ||
36.                 platform == RuntimePlatform.OSXPlayer ||
37.                 platform == RuntimePlatform.LinuxEditor ||
38.                 platform == RuntimePlatform.LinuxPlayer;
39.         }
40.     }
41. }

 

Such a small feature yet it still doesn't exist

 

Code (CSharp):

1.     public static class IL2CPP
2.     {
3.         public static bool IsEnabled
4.         {
5.             get
6.             {
7. #if ENABLE_IL2CPP
8.                 return true;
9. #else
10.                 return false;
11. #endif
12.             }
13.         }

 

They were specifically talking about runtime checking, though