Question

I have a C++ dll. Is there a way to compile it so that it can be used with VS2005/2008/2010 instead of me having to do 3 different builds?

Thanks

Answer 1

You can generally “use” a C++ dll with any version of Visual Studio, if you’re just linking to it.

However, when your dll is compiled, it will be targetted to a specific version of the C++ runtime, so end-users of your program will need to have that runtime (Visual C++ redistributable package) installed on their PC. So if you use a dll built by VS2005 and an exe built by VS2010, your end user will have to install both the 2005 and 2010 redistributable packages. The same generally goes for other libraries if you use them (MFC, etc)

If you do this, you will also have to be careful about memory allocation – memory allocated in one runtime version cannot be safely deallocated by another. So anything that your dll allocates must also be deallocated by the dll, and anything allocated by your exe must not be deallocated by the dll.

As a result, most people will rebuild the dll with the same version of VS as they build the rest of their program in, to minimise the compatibility issues – ultimately it’s much easier to build in each verison of VS than to sort out all the issues involved in not doing so.

(Hint: You can run VS from the command line and get it to build a project/solution, so it’s a 5 minute job to write a batch script that will automate building all three variants in one go)