I need to interpose on a method call in a C++ program (the class resides in a separate shared library). I thought I could use LD_PRELOAD, but i am not sure how this would work (i only found examples of C functions): is there a way to setup interposition for a single method without copying over any code from the interposed class implementation?
It wouldn't be very portable, but you could write your interposing function in C and give it the mangled name of the C++ method. You would have to handle the this parameter explicitly, of course, but I think all ELF ABIs just treat it as an invisible first argument.