How to compile a .NET Core C# project to raw IL code?

Question

I'm trying to set-up a C# project that outputs raw IL code instead of a .EXE. The output file should either look something like this:

IL_0000:  nop         
IL_0001:  ldc.i4.5    
IL_0002:  stloc.0     // a
IL_0003:  ldc.i4.s    18 
IL_0005:  stloc.1     // b
IL_0006:  ldstr       "{0} * {1} = {2}"
IL_000B:  ldloc.0     // a
IL_000C:  box         System.Int32
IL_0011:  ldloc.1     // b
IL_0012:  box         System.Int32
IL_0017:  ldloc.0     // a
IL_0018:  ldloc.1     // b
IL_0019:  mul         
IL_001A:  box         System.Int32
IL_001F:  call        System.Console.WriteLine
IL_0024:  nop         
IL_0025:  ret

...or be the raw binary IL opcodes that can be directly interpreted (or JIT-ed). I'm fine with either option. I tried using ildasm, however, it says that the .EXE file does not have a valid CLR header. I suspect that ildasm does not support .NET Core executables, however I may be wrong.

Answer 1

Try to use ILSpy, dnSpy, dotPeek, IL Viewer in Rider or online SharpLab.

If your application targets .NET Core/5/6/7 then you should decompile App.dll instead of App.exe because this .exe in most cases is just a launcher, without any managed code.