Louis Dionne, code owner of libc++ at Apple and C++ standard committee member, discusses the adoption of the library hardening proposal set for C++26. He emphasizes the importance of enhancing safety and security in C++ through techniques that turn undefined behaviors into clear contract violations. The conversation also delves into innovations like a safe mode for memory safety, evolving hardening techniques, and the balancing act between performance and security. Dionne shares actionable insights for developers eager to adopt these practices today.
The podcast emphasizes the importance of transitioning from .h to .hpp file extensions to enhance clarity and safety in C++.
Bjarne Stroustrup's message highlights the urgent need for the C++ community to prioritize standard library hardening for improved security.
Enhancements like contracts and reflection in C++ promise to boost usability, safety, and streamline development processes for developers.
Deep dives
C++ File Extensions and Header File Standards
The discussion centers around the conventional use of file extensions for C++ header files, specifically the push to transition from the traditional .h extension to alternatives like .hpp. The argument highlights how .h is primarily associated with C headers, which can confuse the differentiation between C and C++. Proponents of the change argue that adopting distinct extensions would enhance clarity for developers and tools by explicitly indicating that a file is meant for C++. This initiative reflects broader community discussions about safety and security in C++, as distinguishing file types is seen as a step towards reducing misconceptions merging both languages.
Bjarne Stroustrup's Warning on C++ Safety
Bjarne Stroustrup's leaked message to the C++ Standards Committee emphasizes urgent action for improving safety and security in C++. He expresses frustration over the lack of progress related to profiles which are seen as vital for the language's future, particularly in light of growing security concerns over the last few years. Stroustrup's call for attention underscores the existing vulnerabilities in C++ as well as the need for a hardened standard library to alleviate risks associated with undefined behaviors. The message encourages the committee and the community to prioritize these issues to ensure the continued evolution and safety of C++.
Exploring Standard Library Hardening
Standard library hardening aims to transform preconditions in the library from undefined behavior into contract violations, ultimately enhancing safety in C++. A clear example includes the standard vector operator, which would crash when the index exceeds its size, rather than allowing potentially harmful unpredictable behavior. This approach, which has roots in practices within libc++, aims to provide developers with more assurance and predictability when using the library. As a result, implementations will include specific checks that help maintain expected behavior and catch errors proactively, fostering code reliability.
Influence of Reflection on Type Erasure in C++
The podcast discusses the potential impact of having reflection in C++ on type erasure libraries, with reflections considered a game-changer for enhancing usability. The inclusion of this feature allows developers to implement solutions that previously required extensive boilerplate code, streamlining the development process. The evolution towards standardization of reflection suggests that developers can soon leverage these improvements to create more efficient and user-friendly libraries. Thus, the integration of reflection not only simplifies coding practices but also holds the potential to redefine type erasure strategies in C++.
Emerging Trends in C++ Developments
The future of C++ is being shaped by significant trends, particularly with the anticipated features from the ongoing evolution of the language. Current interests include the advancement of contracts, enhancing type safety through mechanisms like the proposed typed operator new, which aims to prevent type confusion in memory management. There is growing anticipation surrounding these developments, as they promise to impact many existing coding practices within C++. Overall, the direction of C++ indicates a strong focus on bolstering safety, usability, and modernizing the languages' capabilities to address prevailing challenges.
Louis Dionne joins Phil and Timur. Louis talks to us about his role as code owner of libc++ (clang's standard library implementation) and the standard library hardening proposal that was just accepted into C++26, why this is important, and what you can do even today.
