Question

It seems to me like a no-brainer, but I cannot find any information against or for it.

From the point of view of demangling etc, I don’t suppose this to be a big problem, but I can’t figure out, how I can write a little tiny C program which calls a function from a little tiny C++ library.

I am on linux right now, trying with static binding.

This must be something many people are running into or many books cover, but I feel like a blind gump sitting in front of this problem. Interestingly, there is no such question on SO either.

I do not even know IF this can work, far lesser HOW this has to be done.

Answer 1

Typically, you need to force the C++ compiler to build the library with C linkage for the exported functions.

You can do that by doing the following to your header:

#ifdef __cplusplus
extern "C" {
#endif

void func(void);

/* ... Other function defs go here ... */

#ifdef __cplusplus
}
#endif

Normally, the linker will do C++ name-mangling to the functions, so that the C linker won’t be able to find them. extern "C" forces it not to do that. You need to wrap it in the #ifdef, because extern "C" isn’t valid in C.

UPDATE

As Charles Salvia says in a comment below, you need to ensure that no exceptions make their way out through your interface, because C has no way of handling them (at least not a platform-independent way).