Overloaded functions in C++ DLL def file

Question

I'm writing a C/C++ DLL and want to export certain functions which I've done before using a .def file like this

LIBRARY "MyLib"
EXPORTS
  Foo
  Bar

with the code defined as this, for example:

int Foo(int a);
void Bar(int foo);

However, what if I want to declare an overloaded method of Foo() like:

int Foo(int a, int b);

As the def file only has the function name and not the full prototype I can't see how it would handle the overloaded functions. Do you just use the one entry and then specify which overloaded version you want when passing in the properly prototyped function pointer to LoadLibrary() ?

Edit: To be clear, this is on Windows using Visual Studio 2005

Edit: Marked the non-def (__declspec) method as the answer...I know this doesn't actually solve the problem using def files as I wanted, but it seems that there is likely no (official) solution using def files. Will leave the question open, however, in case someone knows something we don't have overloaded functions and def files.

Answer 1

Function overloading is a C++ feature that relies on name mangling (the cryptic function names in the linker error messages).

By writing the mangled names into the def file, I can get my test project to link and run:

LIBRARY "TestDLL"
EXPORTS
    ?Foo@@YAXH@Z
    ?Foo@@YAXHH@Z

seems to work for

void Foo( int x );
void Foo( int x, int y );

So copy the C++ function names from the error message and write them into your def file. However, the real question is: Why do you want to use a def file and not go with __declspec(dllexport) ?

The mangled names are non-portable, I tested with VC++ 2008.