sortcheck | detecting violations of ordering axioms

sortcheck is a C library. sortcheck has no bugs, it has no vulnerabilities, it has a Permissive License and it has low support. You can download it from GitHub.

SortChecker is a tool for detecting violations of ordering axioms in comparison functions passed to qsort (also bsearch, lfind, etc.). For complex data structures it's very easy to violate one of the requirements. Such violations cause undefined behavior and may lead to all sorts of runtime errors (including unexpected results, inconsistent results across different platforms or even aborts) (also here, see this answer for explanations). The tool works by intercepting qsort and friends through LD_PRELOAD and performing various checks prior to passing control to libc. It could be applied to both C and C++ programs although for the latter std::sort and std::binary_search are more typical (see Future plans). The tool is quite robust - I've successfully booted stock Ubuntu 14, Fedora 22 and Debian chroot and bootstrapped GCC 4.9. The project is MIT-licensed. It has no fancy dependencies, just Glibc and Bash.