F# dlls obfuscation

[GoogleCodeExporter]

Hello,

I try to obfuscate F# dll and I meet some diffcults. It's thrown unhandled 
exception: 

System.InvalidOperationException: Type names do not match: "FSharpFunc `3" != 
"Microsoft.FSharp.Core.OptimizedClosures/FSharpFunc`3...

If I'm not mistaken Obfuscar.exe can obfuscate all types .NET assemblies. So 
the problem is may be in my code?

Could you get me some suggestions for this issue?

Original issue reported on code.google.com by aleksand...@gmail.com on 16 Oct 2012 at 10:29

[GoogleCodeExporter]

Unless you can provide obfuscated assembly with mapping file and the original 
one, it is very hard to tell what is the cause of the exception.

You might try my fork at https://github.com/lextm/obfuscar which has already 
resolved many known issues.

Original comment by lextu...@gmail.com on 28 Apr 2013 at 7:57

[lextm]

Another way to reproduce similar issues is to obfuscate F# compiler with

<?xml version='1.0'?>
<Obfuscator>
 <Var name='InPath' value='.' />
 <Var name='OutPath' value='.' />
<Var name='KeyFile' value='$(InPath)\test.snk' />
 <Var name='HidePrivateApi' value='true' />
 <Module file='$(InPath)\fsc.exe' />
<Module file='$(InPath)\FSharp.Compiler.dll' />
<Module file='$(InPath)\FSharp.Compiler.Interactive.Settings.dll' />
<Module file='$(InPath)\FSharp.Compiler.Server.Shared.dll' />
<Module file='$(InPath)\fsi.exe' />
</Obfuscator>

which leads to a crash

Unhandled Exception: System.TypeInitializationException: The type initializer for 'A.a' threw an exception. ---> System.TypeInitializationException: The type initializer for 'C.K' threw an exception. ---> System.TypeInitializationException: The type initializer for 'C.k' threw an exception. ---> System.TypeLoadException: Method 'GenerateNext' in type 'bD' from assembly 'FSharp.Compiler, Version=4.3.0.0, Culture=neutral, PublicKeyToken=f536804aa0eb945b' does not have an implementation.
   at C.k..cctor()
   --- End of inner exception stack trace ---
   at C.K..cctor()
   --- End of inner exception stack trace ---
   at C.K.a()
   at A.a..cctor()
   --- End of inner exception stack trace ---
   at A.A.A(String[] )

Further analysis shows that an overriding method was not properly skipped.

[lextm]

One generic related issue has been identified and fixed.

[lextm]

A blog post to summarize the investigation, https://blog.lextudio.com/2015/04/obfuscar-f-mono-cecil-and-method-overriding/