Dependable C
2 days ago
- #Undefined Behavior
- #C programming
- #Portability
- Dependable C aims to document a subset of C for developers focusing on portability and reliability, contrasting with the complexity of newer C standards like C23 and C2Y.
- The project highlights the challenges of maintaining compatibility across various C implementations, emphasizing the need for a guide that avoids deprecated features and poorly supported standard parts.
- C's portability and widespread use are underscored, along with its role as a lingua franca in computing, ensuring solutions remain viable across different environments and hardware.
- The document discusses the pitfalls of undefined behavior (UB) in C, explaining how it allows for optimizations but can lead to unpredictable outcomes if not carefully managed.
- Dependable C is positioned as a neutral, universally understood subset of C, prioritizing compatibility over the latest language features, and is distinct from style guides like MISRA.
- The importance of avoiding UB is stressed, with examples showing how assumptions based on UB can lead to optimization-induced bugs that are hard to diagnose.
- The text provides insights into the abstract machine concept in C, illustrating how compilers optimize code while maintaining observable behavior, and the implications for program execution.
- A comprehensive list of dependable and non-dependable C keywords is provided, advising against the use of certain keywords reserved by newer C standards or C++ to ensure compatibility.
- Floating-point types in C are discussed, noting their general dependability but cautioning against reliance on precise arithmetic comparisons due to variability in hardware implementations.
- The document concludes with recommendations for writing dependable C code, including avoiding UB, understanding compiler optimizations, and adhering to a subset of C that ensures wide compatibility.