I’m working on a project where I have the following scenario.

libFirst.lib Has a function foo that I want to access from libSecond.lib. I defined foo as an extern in Second.c and compiling the libraries went OK. Errors occur when I try to link the whole project to build the executable. The linker says that foo is an undefined symbol. I tried adding libFirst.lib and libSecond.lib together to form libComposite.lib and link it.

$> ar ruv libComposite.lib First.obj Second.obj
$> ranlib libComposite.lib

When I view libComposite.lib with tools like nm I see all the symbols are there in the same library but it still not working.

The question is, Is it doable? Can I just add the libraries together and by doing that the function will be defined? If not, What is the best way to achieve a similar behavior?