LLVM / Clang

Rule Changes

As of September 2026: Exploited the undefined behavior; implemented the fix in April 2024

A compiler could legally delete `while (true);` from your C++ program, and Clang actually did: execution fell through into whatever code the linker placed next, producing a demo that printed "Hello world!" after `main` supposedly never ended. That was allowed because trivial infinite loops were undefined behavior since C++11. C++26 makes them well-defined.

Updated Sep 18