Salamander .NET to C# Decompiler Tests

Salamander is a commercial .NET to C# decompiler.

Fibo

For source, see DecompilerFiboDotNetSource. Decompiled source from Salamander:

// Decompiled by Salamander version 1.0.9
// Copyright 2002 Remotesoft Inc. All rights reserved.
// http://www.remotesoft.com/salamander

using System;

class Fibo
{

  private static int fib(int x)
  {
    if (x > 1)
    {
      return fib(x - 1) + fib(x - 2);
    }
    else
    {
      return x;
    }
  }

  // Decompilation not complete! (2)
  public static int Main(string[] args)
  {
    int j = 0;
    try
    {
      j = Convert.ToInt32(args[0]);
    }
    catch (Exception e)
    {
      Console.WriteLine("Input error");
      int k = 1;
      return k;
    }
    goto IL_0027;
    IL_0022:  leave      IL_0027
IL_0027:
    int i = fib(j);
    Console.WriteLine("fibonacci({0}) = {1}", j, i);
    return 0;
  }
}

The decompilation is complete, except for a goto over a leave opcode. This is presumably because Salamander has been tested only on Microsoft compilers (and mostly only on the C# compiler, according to the web page). When the line with leave is commented out, the result compiles and runs correctly.

Casting

For source, see DecompilerCastingDotNetSource. A few casts are required to get this program to compile correctly. Here is the output from Salamander:

// Decompiled by Salamander version 1.0.9
using System;

public class Casting
{

  public static void Main(string[] args)
  {
    for (char ch1 = '\0'; ch1 < '\u0080'; ch1++)
    {
      Console.WriteLine("ascii {0} character {1}", ch1, ch1);
    }
  }
}

The main cast is missing in the WriteLine statement. When the cast is inserted, the program compiles and is correct.

Inner Classes

For source, see DecompilerInnerClassesDotNetSource. When decompiled with Salamander, the result is

// Decompiled by Salamander version 1.0.9
using System;
public class Usa
{
  public class England
  {
    public class Ireland
    {
      public string name = "Dublin";
      public void print_names()
      {
        Console.WriteLine(name);
      }
    }
    public string name = "London";
  }
  public string name = "Detroit";
  public static void Main(string[] args)
  {
  }
}

It reproduced the inner classes correctly. The output compiled with no errors.

Sable Test Program

For source, see DecompilerSableDotNetSource. Here is the result for class MainClass (as produced by Salamander):

public class MainClass
{
  public static void f(short i)
  {
    Drawable drawable;

    bool flag;

    if (i > 10)
    {
      Rectangle rectangle = new Rectangle(i, i);
      flag = rectangle.isFat();
      drawable = rectangle;
    }
    else
    {
      Circle circle = new Circle(i);
      flag = circle.isFat();
      drawable = circle;
    }
    if (!flag)
    {
      drawable.draw();
    }
  }
  public static void Main(string[] args)
  {
    f(11);
  }

The code is reproduced correctly, and no unnecessary casts are generated. Note the lack of a cast to the constant 11 in Main(); unlike Java, no cast is necessary in C#.

Simple Control Flow

For source, see DecompilerControlFlowDotNetSource. For function foo, Salamander produces:

// Decompiled by Salamander version 1.0.9
  // Decompilation not complete! (1)
  public static int foo(int i, int j)
  {
    Exception e;

    for (; i < j; i = j++ / i)
    {
    }
    IL_0018:  leave      IL_002c
    IL_001d:  stloc.0
    i = 10;
    IL_0022:  leave      IL_0000
    IL_0027:  leave      IL_002c
    return j;
  }

It has moved the divide out of the try block into the for loop, which is not correct. The exception code is missing, and the output is obviously wrong.

Image Viewer

For source, see DecompilerImageViewerDotNetSource. This is a slightly larger example, compiled with the Microsoft C# compiler. Still, it has problems with branches over leave instructions, e.g.

  private static Pixbuf GetPixbufFromFile(string filename)
  {
    Pixbuf pixbuf2;

    try
    {
      Pixbuf pixbuf1 = new Pixbuf(filename);
      pixbuf2 = pixbuf1;
    }
    catch (GException e)
    {
      Console.WriteLine(e.GetType());
      Console.WriteLine("Cannot Open file.");
      Environment.Exit(1);
      pixbuf2 = null;
    }
/*
    goto IL_003c;
    IL_000f:  leave      IL_003c
    IL_0037:  leave      IL_003c
IL_003c:
*/
    return pixbuf2;
  }

The rest appears to have decompiled successfully, e.g.

  public static void Main(string[] args)
  {
    if (args.Length > 0 != false)
    {
      Console.WriteLine("\nUSAGE: ImageViewer.exe \n");
      return;
    }
    string str = args[0];
    Application.Init();
    window = new Window("File Viewer");
    window.SetDefaultSize(200, 200);
    window.DeleteEvent += new EventHandler(null.Window_Delete);
    ScrolledWindow scrolledWindow = new ScrolledWindow(
new Adjustment(IntPtr.Zero), new Adjustment(IntPtr.Zero));
    VBox vBox1 = new VBox(false, 2);
    VBox vBox2 = new VBox(false, 0);
    MenuBar menuBar = new MenuBar();
    Menu menu = new Menu();
    MenuItem menuItem1 = new ImageMenuItem("gtk-close",
new AccelGroup(IntPtr.Zero));
    MenuItem menuItem2 = new ImageMenuItem("gtk-open",
new AccelGroup(IntPtr.Zero));
    menuItem1.Activated += new EventHandler(null.Window_Delete);
    menuItem2.Activated += new EventHandler(null.Window_Open);
    menu.Append(menuItem2);
    menu.Append(new SeparatorMenuItem());
    menu.Append(menuItem1);
    MenuItem menuItem3 = new MenuItem("_File");
    menuItem3.Submenu = menu;
    menuBar.Append(menuItem3);
    vBox2.PackStart(menuBar, false, false, 0);
    Toolbar toolbar = new Toolbar();
    toolbar.InsertStock("gtk-open", "Open", String.Empty,
new SignalFunc(null, Window_Open), IntPtr.Zero, 0);
    toolbar.InsertStock("gtk-close", "Close", String.Empty,
new SignalFunc(null, Window_Delete), IntPtr.Zero, 1);
    vBox2.PackStart(toolbar, false, false, 0);
    vBox1.PackStart(vBox2, false, false, 0);
    Pixbuf pixbuf = GetPixbufFromFile(str);
    image = new Image(pixbuf);
    Refresh(str, pixbuf);
    scrolledWindow.AddWithViewport(image);
    vBox1.PackStart(scrolledWindow, true, true, 0);
    scrolledWindow.SetPolicy(1, 1);
    window.Add(vBox1);
    window.ShowAll();
    Application.Run();
  }

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

-- MikeVanEmmerik - 06 Mar 2003
CategoryDecompilation