Converting unmanaged C++ code to C#

Question

Anyone with pointers to a tool/utility for converting unmanaged c++ to c#? I have tried the http://www.pinvoke.net/ site but I cant find reference to this API AddUsersToEncryptedFile on this question .

Answer 1

In general this is really hard, because C++ offer different features than C#: templates, friends, zero-terminated strings, unmanaged pointers, COM, etc., not to mention that parsing C++ is a bitch of a job.

To do it, you need a full C++ parser with name and type resolution, a set of ideas about how to convert each construction (problematic or not) into equivalent C# code, a means to encode those ideas into automated translation steps, and a plan for what to do with those parts of the code that don't translate well (typically, "fix by hand").

Using the DMS Software Reengineering Toolkit , which provides all the requisite machinery, my company, Semantic Designs, actually constructed such a tool, but never used it, for a large customer that wanted to move 800K SLOC of C++ into C#. About 2/3 of the way through the project, the customer had some birdcage management reshuffle, and the new managers decided not to proceed to save money (the tool itself was doing fine).

Answer 2

You may find this story interesting :

Disclosing How C#-SQLite Was Ported to .NET

SQLite is a C program, but there are some good high level tips here.

Answer 3

Is all you need a declaration of that API? There's a tool called PInvoke Interop Assistant you can use, but personally I prefer the DIY approach. It's not that hard.

Try the following definitions

struct EFS_CERTIFICATE_BLOB
{
    public int dwCertEncodingType;
    public int cbData;
    public IntPtr pbData;
}

struct ENCRYPTION_CERTIFICATE
{
    public int cbTotalLength;
    public IntPtr pUserSid;
    public IntPtr pCertBlob;
}

struct ENCRYPTION_CERTIFICATE_LIST
{
    public int nUsers;
    public IntPtr pUsers;
}

[DllImport("advapi32.dll", CharSet=CharSet.Unicode)]
static extern uint AddUsersToEncryptedFile(string lpFileName, ref ENCRYPTION_CERTIFICATE_LIST pUsers);

Answer 4

If you're porting C++ code to C#, then you should perhaps consider converting the unmanaged C++ code to C++/CLI. You can then begin to port to C# in a more controlled manor (ie. by one piece at a time - ideally unit tested as you go).

An alternative to converting to C++/CLI would be to wrap your existing unmanaged C++ code using SWIG , however the migration will be made more difficult using this method.