Undefined behaviour

Pointers arithmetic

Undefined behaviour on pointer arithmetic. Use clang flags:

-fsanitize=undefined -Wnull-pointer-arithmetic

TLDR:

• Null pointer arithmetic.

  If p is a null pointer to an object type, the C expression p + 0 always evaluates to p on modern hosts, even though the standard says that it has undefined behavior.

• the result of pointer arithmetic going beyond the boundary of an array (plus one).

Data race

A data race is undefined behaviour. Data race TLDR: multiple threads accessing the same data, with one of the access being a write.

Reading uninitialized variables.

Reading uninitialized variables is undefined behaviour.