Undefined behavior can literally erase your hard disk

Mon, 04 Sep 2017 20:00:00 +0300

It is no secret that C and C++ are chock-full of pitfalls of undefined behavior. The C++ standard describes it as:

behavior for which this International Standard imposes no requirements

Modern compilers, with optimizations on, often assume that undefined behavior is never invoked in the program and try to make sense of the code under that assumption. When a program actually does invoke undefined behavior, this conflicts with the assumption under which the compiler generated code, often resulting in strange, or even outright paradoxical results. (I like to call those cases “paranormal behavior”, but it still hasn’t caught on.)

compiler-optimizations on Mature Pessimizations - A programming blog by Theodoros Chatzigiannakis

Undefined behavior can literally erase your hard disk