undefined | Better HN

0 pointsAaronBallman6y ago0 comments

> Do you think Annex K of C11 will be widely adopted by programmers or unused? Why aren't people adopting it?

So far, it's not been widely adopted. Part of the issue is that there are specification issues relating to threads and the constraint handlers, and part of the issue is that popular libc implementations have actively resisted implementing the annex.

That said, I field questions about Annex K on a regular basis and there are a few implementations in the wild, so there is user interest in the functionality.

> Do you see the use of any analysis tools that are particularly effective for finding memory safety issues?

<biased opinion>I think CodeSonar does a great job at finding memory safety issues, but I work for the company that makes this tool.</biased opinion>

I've also had good luck with the memory and address sanitizers (https://github.com/google/sanitizers) and tools like valgrind.

> C++ added in smart pointers to its specification. Are there any plans to do something similar in future C specifications?

We currently don't have any proposals for adding smart pointers to C. Given that C does not have constructors or destructors, we would have to devise some new mechanism to implement or replace RAII in C, which would be one major hurdle to overcome for smart pointers.

0 comments

2 comments · 2 top-level

hedora6y ago

I’ve had good luck (in C++) replacing the underlying memory allocator with one that tracks leaks by allocation type (which is fast enough for production use).

This can be done in C, but the calling code has to spell malloc and free differently.

In debug mode, configuring malloc to poison (and add fences) on allocation and free finds most of the remaining things.

These techniques tend to have much lower runtime overhead than valgrind (2-digit percentages vs 5-10x), so they can be left on throughout testing and partially enabled in production.

They find >90% of the memory bugs that I write (assuming valgrind finds 100%). YMMV.

jcelerier6y ago

> We currently don't have any proposals for adding smart pointers to C. Given that C does not have constructors or destructors, we would have to devise some new mechanism to implement or replace RAII in C, which would be one major hurdle to overcome for smart pointers.

why would you have to devise a new mechanism and not borrow one from one of the thousand other mechanisms already existing in PL litterature for this ?

j / k navigate · click thread line to collapse