C's `defer` Keyword: A Blitz to Prevent Memory Leaks

A new feature is coming to C: `defer`. It acts as a general-purpose 'undo' mechanism, ensuring that a set of statements are executed regardless of how a code block exits, crucial for resource cleanup like freeing memory or unlocking mutexes. `defer` builds upon existing compiler extensions and similar features in other languages. The article details `defer`'s functionality, scope, and differences from similar constructs in Go, with examples illustrating its use. The author urges compiler vendors to implement `defer` promptly to enhance C code safety and maintainability, preventing memory leaks like those seen in CVE-2021-3744.