Assembler & Disassembler

.NET compilers like mcs or mbas do not compile to native code, but to the COMMON INTERMEDIATE LANGUAGE.

IL code looks like this:

// hello world dissassembled with monodis

.assembly extern mscorlib
{
  .ver 0:0:0:0
}
.assembly 'hello'
{
  .hash algorithm 0x00008004
  .ver  0:0:0:0
}
  .class private auto ansi beforefieldinit Hello
        extends [mscorlib]System.Object
  {

    // method line 1
    .method public hidebysig  specialname  rtspecialname
           instance default void .ctor()  cil managed
    {
        // Method begins at RVA 0x20ec
        // Code size 7 (0x7)
        .maxstack 8
        IL_0000: ldarg.0
        IL_0001: call instance void valuetype [corlib]System.Object::.ctor()
        IL_0006: ret
    } // end of method instance default void .ctor()

    // method line 2
    .method public static
           default void Main()  cil managed
    {
        // Method begins at RVA 0x20f4
        .entrypoint
        // Code size 11 (0xb)
        .maxstack 8
        IL_0000: ldstr "Hello Mono World!"
        IL_0005: call void class [corlib]System.Console::WriteLine(string)
        IL_000a: ret
    } // end of method default void Main()

  } // end of type Hello

• ilasm: The Mono Assembler can be given disassembled text, and it creates aan assembly file. This is very important, because many compilers don't create the assembly themselves, and depend on this tool. Of course it can be also seen as a form of a compiler.
• monodis: The Mono Disassembler extracts code like shown above from an assembly.

Both tools will be described in detail in the next two sub-chapters.

A. Credits