Hello people,

So lately I have been starting to work on a 2D game engine for the fun of it. Although it's just for the fun of it, should it one day be something worthwhile, I would like to share it with others.

Now the problem I have run in to has to do with the fact that I want to compile the engine into a static library, but as a base, I am working with SDL (or SFML, haven't really decided yet). Because I want the user to only have to include 1 dependency, I link it with the library I am making. Effectively I am just abstracting away other libraries.

Now this is working fine and all, but I stumble upon the lovely warnings:

1>SDL2_image.lib(SDL2_image.dll) : warning LNK4006: __NULL_IMPORT_DESCRIPTOR already defined in SDL2.lib(SDL2.dll); second definition ignored
1>SDL2_image.lib(SDL2_image.dll) : warning LNK4221: This object file does not define any previously undefined public symbols, so it will not be used by any link operation that consumes this library

Now I have found several solution, or rather answers to "fix" this.

The most common answer is to simply let the user link with the library, but that is exactly the thing I want to prevent.

One other way is to prevent defining the same symbols or make sure they're the same if it can't be prevented, but I don't have access to SDL nor do I really want fiddle around in it.

The last option is to ignore it, mostly it will work out fine anyway, be it the fact that I don't like the "mostly" part.

So my question to you people: What do you guys advice on doing about this? Building a library that consists of other libraries.

Perhaps there are some more elegant or better solutions. Anything at all would help.

May I ask what did you do to link that in the first place? You say you're making a static library but as far as I know static libraries can't automatically reference other libraries because they're just archives of object files, so the other libraries it needs have to be linked when the program is built (I think I saw somewhere a workaround with GCC that tells the toolchain to include other libraries, but I'm not sure how reliable is that).

May I ask what did you do to link that in the first place? You say you're making a static library but as far as I know static libraries can't automatically reference other libraries because they're just archives of object files, so the other libraries it needs have to be linked when the program is built (I think I saw somewhere a workaround with GCC that tells the toolchain to include other libraries, but I'm not sure how reliable is that).

I add them to the Additional Dependencies in the projects configuration -> Librarian

http://www.joeyfladderak.com/ImageUploads/20130710123336467.png

I add them to the Additional Dependencies in the projects configuration -> Librarian

Don't do that. Create a post build step to merge the resulting libraries, e.g.

lib.exe /OUT:CombinedLib.lib lib1.lib lib2.lib lib3.lib

Wouldn't that in theory still give the same problem?

Also, what would lib.exe be?