C#•13mo ago

❔ how do i print the bytecode generated from a ILGenerator? (im getting an error)

i am trying to generate and print csharp bytecode using ILGenerator and AssemblyBuilder, ModeuleBuilder, etc, but when i try to get my bytecode using the code below, i get the following error:

'System.InvalidOperationException' occurred in System.Private.CoreLib.dll: 'Operation is not valid due to the current state of the object.'

'System.InvalidOperationException' occurred in System.Private.CoreLib.dll: 'Operation is not valid due to the current state of the object.'

my code:

AssemblyName assemblyName = new AssemblyName("CSharpBytecode");
AssemblyBuilder assemblyBuilder = AssemblyBuilder.DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.Run);

ModuleBuilder moduleBuilder = assemblyBuilder.DefineDynamicModule("CSharpBytecode");
TypeBuilder typeBuilder = moduleBuilder.DefineType("CSharpBytecode", TypeAttributes.Public);
MethodBuilder methodBuilder = typeBuilder.DefineMethod("MyMethod", MethodAttributes.Public);

ILGenerator ilGenerator = methodBuilder.GetILGenerator();

ilGenerator.Emit(OpCodes.Ldstr, "Hello, world!");
ilGenerator.Emit(OpCodes.Ret);

byte[] methodBody = methodBuilder.GetMethodBody().GetILAsByteArray(); // this errors

AssemblyName assemblyName = new AssemblyName("CSharpBytecode");
AssemblyBuilder assemblyBuilder = AssemblyBuilder.DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.Run);

ModuleBuilder moduleBuilder = assemblyBuilder.DefineDynamicModule("CSharpBytecode");
TypeBuilder typeBuilder = moduleBuilder.DefineType("CSharpBytecode", TypeAttributes.Public);
MethodBuilder methodBuilder = typeBuilder.DefineMethod("MyMethod", MethodAttributes.Public);

ILGenerator ilGenerator = methodBuilder.GetILGenerator();

ilGenerator.Emit(OpCodes.Ldstr, "Hello, world!");
ilGenerator.Emit(OpCodes.Ret);

byte[] methodBody = methodBuilder.GetMethodBody().GetILAsByteArray(); // this errors

PS, i have no clue if this is beginner, intermediate, or advanced (and im likely in way over my head here)

13 Replies

exokem•13mo ago

Is the error from GetMethodBody or GetILAsByteArray?

FinnlandOP•13mo ago

getMethodBody i tried looking it up and it might be that the method doesnt have a body, but the only way i can find to give it a body is exactly what im doing here

exokem•13mo ago

exokem•13mo ago

MethodBuilder does not seem to provide an override for GetMethodBody, and none is provided by any of its base types so it throws an exception what's your use case for generating IL? there may be a better API

FinnlandOP•13mo ago

its the compiled result of a programming language im writing

exokem•13mo ago

are you very familiar with IL? I have worked on something similar where I just manually generated the IL

FinnlandOP•13mo ago

not at all i was having a lot of trouble trying to learn how to generate it manually, because i could only find code like this i was hoping that being able to print the result would help me learn if you have any rescources or advice for generating it manually i would appreciate it

exokem•13mo ago

https://www.codeproject.com/Articles/3778/Introduction-to-IL-Assembly-Language this is what I used to learn how IL works there are also a couple of really annoyingly difficult to find tools for verifying and compiling IL into an executable

CodeProject

Introduction to IL Assembly Language

Start using IL Assembly Language to debug your code at low level and understand how .NET deals with your high level code

exokem•13mo ago

PEVerify or ILVerify for verifying an executable/dll ILAsm for compiling executables/dlls IL is object oriented and you can use the mscorlib for string operations (and various other things)

FinnlandOP•13mo ago

ok tysm!

exokem•13mo ago

if you run into any specific problems or have questions feel free to dm or reply here (for as long as this thread will be open)

FinnlandOP•13mo ago

ok thanks i appreciate it idk how long i have rn but i may post anothger thread some other time

Accord•13mo ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

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❔ how do i print the bytecode generated from a ILGenerator? (im getting an error)