---+ Anakrino .NET to C# Decompiler Tests
[[http://www.saurik.com/net/exemplar/][Anakrino]] is a .NET to C# decompiler,
released under a BSD-like license. These tests refer to "Interim #9" (Anakrino9.zip).
Anakrino does not save an entire file of code to write to a source file; I had to
add the text in *bold* to the given output.

The distributed binaries require Windows XP (or perhaps another Windows based .NET JIT).
It would not run under Mono version 0.20 (current in early March 2003).

%TOC%
---++ Fibo
For source, see DecompilerFiboDotNetSource. Decompiled source from Anakrino:
<pre>
<strong>using System;
class Fibo {</strong>
private static int fib(int x) {
	 if (x > 1)
		  return Fibo.fib(x - 1) + Fibo.fib(x - 2);
	 return x;
}

public static int Main(string[] args) {
	 int local0;
	 int local1;
	 Exception local2;
	 int local3;

	 local1 = 0;
	 try {
		  local1 = Convert.ToInt32(args[0]);
	 }
	 catch (Exception local2) {
		  Console.WriteLine("Input error");
		  local3 = 1;
		  <{ class ILEngineer::Ops::MSIL::Leave }>
	 }
	 local0 = Fibo.fib(local1);
	 Console.WriteLine("fibonacci({0}) = {1}", local1, local0);
	 return 0;
	 return local3;
}
<strong>}</strong>
</pre>

There are several errors in this output. Most obviously, there is the _Leave_ code
which should be =return local3=.
The =return local3;= at the end should be removed.
Finally, =local2= is declared twice. 
When all these changes are made, the result compiles and runs correctly.

---++ Casting

For source, see DecompilerCastingDotNetSource. Here is the output from Anakrino:
<pre>
<strong>using System;
class Casting {</strong>
public static void Main(string[] args) {
	 char local0;
	 char local1;

	 local0 = '';
	 while (local0 < 128) {
		  Console.WriteLine("ascii {0} character {1}", local0, local0);
		  local1 = local0 + 1;
		  local0 = local1;
	 }
}
<strong>}</strong>
</pre>
The main cast is missing in the =WriteLine= statement.
The character constant for character 0 is ='\0'= , not =''= as given.
The line =local1 = local0 + 1;= needs to be replaced with =local1 = (char) (((int)local0)+1);=.
When all these changes are made, the program compiles
and is correct.

---++ Inner Classes
For source, see DecompilerInnerClassesDotNetSource. When decompiled with Anakrino, the result appears
correct, but tedious to piece together from the individual functions (and constructors).
The =print_names= function decompiles as follows:

<verbatim>
public void print_names() {
	 Console.WriteLine(this.name);
}
</verbatim>
The =this.= is not needed.

---++ Sable Test Program
For source, see DecompilerSableDotNetSource.
The decompiler exited with a runtime fault when this program was loaded.

---++ Simple Control Flow

For source, see DecompilerControlFlowDotNetSource.
The decompiler exited with a runtime fault when this program was loaded.

---++ Image Viewer

For source, see DecompilerImageViewerDotNetSource.
This program was compiled with a Microsoft compiler, and so should be easy to decompile.
Unfortunately, it had problems with the same method that caused problems for Salamander:
<verbatim>
private static Pixbuf GetPixbufFromFile(string filename) {
	 Pixbuf local0;
	 GException local1;
	 Pixbuf local2;

	 try {
		  local0 = new Pixbuf(filename);
		  local2 = local0;
		  <{ class ILEngineer::Ops::MSIL::Leave }>;
	 }
	 catch (GException local1) {
		  Console.WriteLine(local1.GetType());
		  Console.WriteLine("Cannot Open file.");
		  Environment.Exit(1);
		  local2 = null;
		  <{ class ILEngineer::Ops::MSIL::Leave }>;
	 }
	 return local2;
}
</verbatim>
Also, =local1= is declared twice.

For completeness, here is the =main= function.
<verbatim>
public static void Main(string[] args) {
	 string local0;
	 ScrolledWindow local1;
	 VBox local2;
	 VBox local3;
	 MenuBar local4;
	 Menu local5;
	 MenuItem local6;
	 MenuItem local7;
	 MenuItem local8;
	 Toolbar local9;
	 Pixbuf local10;

	 if (args.Length > 0 == 0) {
		  Console.WriteLine("\nUSAGE: ImageViewer.exe <filename>\n");
		  return;
	 }
	 local0 = args[0];
	 Application.Init();
	 ImageViewer.window = new Window("File Viewer");
	 ImageViewer.window.SetDefaultSize(200, 200);
	 ImageViewer.window.add_DeleteEvent(new EventHandler(null,
ImageViewer.Window_Delete));
	 local1 = new ScrolledWindow(new Adjustment(IntPtr.Zero),
new Adjustment(IntPtr.Zero));
	 local2 = new VBox(0, 2);
	 local3 = new VBox(0, 0);
	 local4 = new MenuBar();
	 local5 = new Menu();
	 local6 = new ImageMenuItem("gtk-close", new AccelGroup(IntPtr.Zero));
	 local7 = new ImageMenuItem("gtk-open", new AccelGroup(IntPtr.Zero));
	 local6.add_Activated(new EventHandler(null, ImageViewer.Window_Delete));
	 local7.add_Activated(new EventHandler(null, ImageViewer.Window_Open));
	 local5.Append(local7);
	 local5.Append(new SeparatorMenuItem());
	 local5.Append(local6);
	 local8 = new MenuItem("_File");
	 local8.Submenu = local5;
	 local4.Append(local8);
	 local3.PackStart(local4, false, false, 0);
	 local9 = new Toolbar();
	 local9.InsertStock("gtk-open", "Open", String.Empty,
new SignalFunc(null, ImageViewer.Window_Open), IntPtr.Zero, 0);
	 local9.InsertStock("gtk-close", "Close", String.Empty,
new SignalFunc(null, ImageViewer.Window_Delete), IntPtr.Zero, 1);
	 local3.PackStart(local9, false, false, 0);
	 local2.PackStart(local3, false, false, 0);
	 local10 = ImageViewer.GetPixbufFromFile(local0);
	 ImageViewer.image = new Image(local10);
	 ImageViewer.Refresh(local0, local10);
	 local1.AddWithViewport(ImageViewer.image);
	 local2.PackStart(local1, true, true, 0);
	 local1.SetPolicy(1, 1);
	 ImageViewer.window.Add(local2);
	 ImageViewer.window.ShowAll();
	 Application.Run();
}
</verbatim>

The translation  "if (args.Length > 0 == 0)"  seems clumsy and confusing.

---++ Conclusion

As of early March 2003, Anakrino is not a mature decompiler.
It may be useful for examining snippets of code here and there,
or even for decompiling small assemblies if you have a fair bit of time spare.

-- Main.MikeVanEmmerik - 07 Mar 2003<br>
CategoryDecompilation