In this talk we will describe “-fbounds-safety”, a new language extension implemented in Clang that brings bounds safety to the C language. The language extension addresses multiple of the practical challenges that have made existing approaches to safer C dialects difficult to adopt. Our approach facilitates incremental adoption by preserving source compatibility with standard C and preserving ABI-compatibility with C binaries. It also minimizes adoption effort by reconciling wide pointers (a.k.a. “fat” pointers) with ABI-preserving bounds annotations. “-fbounds-safety” has been adopted on millions of lines of production C code and proven to work in an industrial setting.

Zheng Wang