Liangxu Linux

Mar 18, 2023 · Fundamentals

Mastering GNU C Extensions: typeof, Zero‑Length Arrays, Case Ranges and More in the Linux Kernel

This article explains key GNU C extensions used throughout the Linux kernel—including typeof, zero‑length (flexible) arrays, case range labels, designated initializers, variadic macros, function and variable attributes, built‑in functions, asmlinkage and UL suffixes—showing why they exist and how to apply them safely with concrete code examples.