Abi

Virtual functions are one of C++’s core features, enabling runtime polymorphism. Most C++ programmers use them regularly, yet few understand how they work in practice. What does the compiler actually generate when you declare a function virtual? How does the program figure out which implementation to call at runtime? Where is the vtable data actually stored? This blog post is focused on answering these questions. The C++ standard specifies behavior but not implementation. This post describes the Itanium C++ ABI used by most platforms, with the notable exception of Microsoft MSVC. ...