How to run regasm.exe from a C++ program (.NET 4) - c++

Question

I need to register a .NET COM dll from a C++ program that is using it. For .NET versions older then .NET 4 this is explained in How to run regasm.exe from a C++ program?. Following is the minimal code (no checks) that provides the path to an older version of the CLR.
CComBSTR mscoreeName("mscoree.dll");
HINSTANCE hMscoree = CoLoadLibrary(mscoreeName, FALSE);
typedef HRESULT (WINAPI *LPFNGETCORSYSDIR)(LPWSTR, DWORD, DWORD*);
LPFNGETCORSYSDIR lpfunc = (LPFNGETCORSYSDIR)GetProcAddress(hMscoree,_T("GetCORSystemDirectory"));
DWORD bufferSize = 256;
DWORD bufferUsed;
LPWSTR pwzBuffer = new WCHAR[bufferSize];
(*lpfunc)(pwzBuffer, bufferSize, &bufferUsed);
However since I use .NET 4 the method GetCORSystemDirectory is superseded by the ICLRRuntimeInfo::GetRuntimeDirectory which is not an entry point in mscoree.dll (checked with depends). According the documentation on MSDN the method is included as a resource in MSCorEE.dll.
Question is how to get access to this method from C++?
Besides that I'm wondering if there is no easier way...

Answer 1

The problem with the way of working in the question is in finding the correct location of RegAsm. Thanks to the comment of Hans Passant to use RegistrationService.RegisterAssembly I changed the ClassLibrary into a self-registering executable.
static void Main(string[] args)
{
if (args.Length != 1)
{
ShowHelpMessage();
return;
}
if (args[0].CompareTo("/register") == 0)
{
Assembly currAssembly = Assembly.GetExecutingAssembly();
var rs = new RegistrationServices();
if (rs.RegisterAssembly(currAssembly, AssemblyRegistrationFlags.SetCodeBase))
{
Console.WriteLine("Succesfully registered " + currAssembly.GetName());
} else
{
Console.WriteLine("Failed to register " + currAssembly.GetName());
}
return;
}
if (args[0].CompareTo("/remove") == 0)
{
Assembly currAssembly = Assembly.GetExecutingAssembly();
var rs = new RegistrationServices();
if (rs.UnregisterAssembly(currAssembly))
{
Console.WriteLine("Succesfully removed " + currAssembly.GetName());
}
else
{
Console.WriteLine("Failed to remove " + currAssembly.GetName());
}
return;
}
ShowHelpMessage();
}