My guess would be that LLVM is not so much motivated by better benchmarks. You could always make it a parameter. The bigger issue usually is: If we mark something as an error, which is actually allowed by the C standard, then lots big old libraries will not compile anymore and nobody is willing to fix all the old code.
If we miscompile (or outright delete) something which is marked "undefined behaviour" by the C standard, then lots of old libraries will build without errors, but fail in various fun ways during use, including having severe security issues. I think failing the build is better than giving me a library with deleted NULL checks and whatnot.
> then lots big old libraries will not compile anymore and nobody is willing to fix all the old code.
This is begging for one question in my opinion. Should we keep using old libraries that nobody is maintaining anymore? Isn't that a big security issue?
