Home / Questions / 18198
Accepted
Augusto Herbel
Asked: 2020-07-31 16:11:29 +0800 CST 2020-07-31 16:11:29 +0800 CST

InvalidProgramException in .IL (Microsoft Intermediate Language) file

  • 772

This is the code

.assembly extern mscorlib {}
.assembly UsingTheArgs {}

.method static public void main() cil managed
{
  .entrypoint
  .maxstack 1

  ldstr "Hi my name is {0}"

  ldarg.0
  ldc.i4.0
  ldelem.ref

  call void [mscorlib]System.Console::WriteLine(string, object)
  ret
}

And it generates a System.InvalidProgramException, it tells me:

Common Language Runtime detected an invalid program in main()

What can be caused this? I'm learning MSIL and this is one of my first examples that I try and I really have no idea why it can't work.

.net

2 Answers

  1. Best Answer

    I already found the solution. The values ​​on the stack were not in order when the method was called System.Console.WriteLine, a was passed first objectand then a string, instead of a stringand then a object. I created two local variables and with those local variables I put in order the parameters.
    I leave the correct code so you can see what the errors were:

    .assembly extern mscorlib {}
.assembly MyFirstSample {}

.method static public void main(class System.String[]) cil managed
{
  .entrypoint
  .maxstack 2
  .locals init (string message,
                string argument)

  ldstr "Hi my name is {0}"
  stloc message

  ldarg.0
  ldc.i4.0
  ldelem.ref
  stloc argument

  ldloc message
  ldloc argument

  call void [mscorlib]System.Console::WriteLine(string, object)
  ret
}
    • 1

  2. I do not think that IL is so designed to be learned, it is even more doubtful that there are manuals to learn it, perhaps if it is used as a means to analyze

    You could use tools like being

    http://ilspy.net/

    where it applies a disassembler of .exe or dll to be able to analyze it both in IL and in .net code

    you could create your program in c#, apply ILSpy and compare with the code you are creating to see what differences you notice and thus deduce what you are missing

    I think that's a good technique to learn, write code in a known language like C# and see what IL generates

    • 0