Al's Game Programming Blog

I finally got my C# to C++ translator doing something useful! It's still early days but I successfully translated a C# program into C++. The C# program was this:

class Program

{

    static void Main(string[] args)

    {

        for (int i = 0; i != 10; ++i)

        {

            Console.WriteLine("Hello world!");

        }

    }

}

I compiled this with the Microsoft C# compiler, which generated Program.exe and Program.pdb. My translator loaded these two files, extracted all the information (metadata, debug information and MSIL assembly code) and then output this:

void Main()

{

NativeInt si0;

void* sr0;

NativeInt si1;



#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

L0: {

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

    {

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

        Int8 CS_36_4_36_0000;

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

        {

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

            Int32 i;

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

            si0 = 0;

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L1: i = si0;

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L2: goto L20;

#line 17 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L4: sr0 = InternString("Hello world!");

#line 17 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L9: ::System::Console::WriteLine((::System::String*) sr0);

#line 17 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L14: void(0);

#line 18 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L15: void(0);

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L16: si0 = i;

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L17: si1 = 1;

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L18: si0 = si1 + si0;

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L19: i = si0;

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L20: si0 = i;

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L21: si1 = 10;

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L23: si0 = si1 == si0;

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L25: si1 = 0;

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L26: si0 = si1 == si0;

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L28: CS_36_4_36_0000 = si0;

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L29: si0 = CS_36_4_36_0000;

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

            L30: if (si0) goto L4;

#line 15 "f:/permanent/dev/ilvisitor/test1/program.cs"

        }

#line 19 "f:/permanent/dev/ilvisitor/test1/program.cs"

        L32: return;

#line 19 "f:/permanent/dev/ilvisitor/test1/program.cs"

    }

#line 19 "f:/permanent/dev/ilvisitor/test1/program.cs"

}

}

It looks like I was right when I said it would not be comprehensible to humans! Anyway, I compiled this C++ function, which generated another executable. I ran that and got the expected output:

Hello world!

Hello world!

Hello world!

Hello world!

Hello world!

Hello world!

Hello world!

Hello world!

Hello world!

Hello world!

Notice all the "#line" directives. These allow me to debug the C# program using a C++ debugger. This is working pretty well. I can set breakpoints in the C# source file (rather than the translated C++ one) and single step through the C# code. I also use the same variable names in the translation so I can see their values in the debugger as I step through. It's just as good as using a C# debugger.

For fun I might try running it on a console. It would be cool to get a screenshot of CodeWarrior debugging a C# program running on a non-Microsoft platform :)