Defer available in gcc and clang
Hacker News
February 16, 2026
AI-Generated Deep Dive Summary
The article discusses the availability of the `defer` feature in GCC and Clang compilers, highlighting its integration as per Technical Specification (TS) 25755. The `defer` feature, designed for cleanup handling, has been implemented to address issues like resource leaks and spaghetti code in C programming. While Clang users can access this feature starting from version 22 with the `-fdefer-ts` option, GCC implementation is yet to be tested extensively but is expected to work similarly.
The author emphasizes the importance of adopting `defer` for better code reliability, especially in scenarios where resources must be properly released even on rare or unexpected function exits. For example, using `defer` ensures that mutexes are unlocked after critical sections and memory allocations are freed correctly. The implementation details show compatibility across various compilers, with GCC relying on nested functions and Clang requiring specific options for seamless integration.
The article also addresses concerns about the security and efficiency of the `defer` implementation. Despite historical debates over nested functions in GCC, the author assures that there’s no risk of stack exploits or hidden function trampolines. This makes `defer` a secure and reliable choice for modern C programming. However, older Clang versions are not supported due to incompatible block syntax, limiting its use on very old systems but ensuring broad compatibility otherwise.
In conclusion, the availability of `defer` in GCC and Clang marks a significant advancement in resource management for C developers. By simplifying cleanup handling and reducing potential errors, `defer` enhances code reliability and maintainability, making it a valuable tool for tech startups and developers seeking efficient coding solutions.
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Originally published on Hacker News on 2/16/2026