SWIG C++ Precompiled DLL

Question

I have a third party DLL (no header file) written in C++ and I am able to get the function prototype information from the developer, but it is proprietary and he will not provide the source.

I've gone through the SWIG tutorial but I could not find anywhere specifying how to use SWIG to access any functions with only the DLL file. Everything on the tutorial shows that I need to have the header so SWIG knows what the function prototypes look like.

Is SWIG the right route to use in this case? I am trying to load this DLL in Python so I can utilize a function. From all of my research, it looks like Python's ctypes does not work with C++ DLL files and I am trying to find the best route to follow to do this. Boost.python seems to require changing the underlying C++ code to make it work with Python.

To sum up, is there a way to use SWIG when I know the function prototype but do not have the header file or source code?

Answer 1

Even without a header file, if you have the prototype, you can make a header file yourself, or just enter the prototype directly in the SWIG interface file.

For example, if the prototype is:

int sum(const std::vector<int>& vint);

The SWIG interface would be:

%module example
%{
    #include <vector>
%}
%include <std_vector.i>                # SWIG support
%template() std::vector<int>;          # Generate code to support template instance.

int sum(const std::vector<int>& vint); # Generate wrapper for function.

Answer 2

To use a library (static or dynamic), you need headers and library file .a, .lib...

Its true for c++ and I think its the same for Python

Answer 3

SWIG cannot be used without the header files. Your only option is a lib like ctypes. If you find ctypes doesn't do it for you and you can't find alternative then post a question with why ctypes not useable in your case.