Undefined Behavior during pointer arithmetic on stack-allocated arrays

In C (ISO/IEC 9899), pointer arithmetic is permitted within the bounds of an array, including one element past the end. However, dereferencing a pointer that has moved beyond this boundary triggers Undefined Behavior (UB).

A specific concern arises when compiler optimizations (such as -O2 or -O3) are applied. Because the compiler assumes UB never occurs, it may optimize away conditional checks intended to prevent out-of-bounds access, potentially altering the program's logic in production builds compared to debug builds.

Given that the C standard provides no built-in bounds checking, there is uncertainty regarding the most reliable way to verify these boundaries without introducing significant runtime overhead.

• Does the compiler consistently optimize away safety checks that rely on the assumption that a pointer remains within its allocated buffer?
• What are the primary differences in how these memory errors manifest when switching from a debug build to a high-optimization build?