Weak dependency on a shared library on Linux

I want my executable to be “optionally dependent” on another shared object. Thus, it can work without some characters if there is no DSO.

I can achieve this with calls dlopen/dlsym, but I have to manually load each character and add wrappers for them as follows:

void *my_lib = dlopen("my_lib.so", RTLD_LAZY);  
if (!my_lib)  {
    // ok, I promise not to touch my_lib symbols
} else {
    my_foo_ptr = dlsym(my_lib, "my_foo");
    my_bar_ptr = dlsym(my_lib, "my_bar");
}

... my_foo(...) {
    assert(my_foo_ptr);
    return (*my_foo_ptr)(...);
}

... my_bar(...) {
    assert(my_foo_ptr);
    return (*my_bar_ptr)(...);
}

This is dumb code, and it directly depends on the "my_lib.so" ABI, which means that I have to update it every time I update the library.

I am looking for a way to ld.sodo it for me. Thus, the ideal would be as follows:

void *my_lib = dlopen("my_lib.so", /* bring me all my symbols */);  
if (!my_lib)  {
    // ok, I promise not to touch my_lib symbols
} else {
    // ok, I can directly call symbols from my_lib.so
    my_foo();
    my_bar();
}

: 1. ? my_lib.so, my_lib.so. , ld undefined.
2. dlopen() my_lib.so ?

: , DT_NEEDED . , ld .