How about another explicit method

Generate in project dir file like this

// static_init.cpp
#define INIT(lib) extern int lib##_init(); lib##_init();
static int init() {
    INIT(lib1)
    INIT(lib2)
    INIT(lib3)
    // ....
    return 0;
}
static int init_result=init();

and link it to project. Just like .def file.
This is simple and you can control order of initialization. And no need of inline valiables support.