https://peter0x44.github.io/tags/abi/Recent content in Abi on File Descriptor TwoHugo -- 0.148.1en-us2025 Peter0x44Sat, 28 Feb 2026 12:00:00 +0000https://peter0x44.github.io/posts/vtables-itanium-abi/Sat, 28 Feb 2026 12:00:00 +0000https://peter0x44.github.io/posts/vtables-itanium-abi/<p>Virtual functions are one of C++&rsquo;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 <code>virtual</code>? 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.</p> <p>The C++ standard specifies behavior but not implementation. This post describes the <a href="https://itanium-cxx-abi.github.io/cxx-abi/abi.html">Itanium C++ ABI</a> used by most platforms, with the notable exception of Microsoft MSVC.</p>