That's not helping. I'm talking about wrong decisions, made during compile-time optimizations, like assuming dead code or a value being NULL, and then ripping apart the written code. Without warning.

Or the famous optimized away memset call. Which is a security issue. At least a warning would be in order. Or at least an analyzer warning.

gcc also has ubsan since gcc version 4.9. Many of the sanitizers are shared by the clang & gcc projects. Some functionality, like emitting errors on unsigned overflow, is confined to clang.