__noreturn

The __noreturn modifier can be placed immediately after a function type declaration to specify that a function can never return. For example, the exit function is marked with __noreturn.

It is not necessary for functions that call __noreturn functions such as exit to explicitly specify that they cannot return. The compiler will automatically determine that such functions are __noreturn. This attribute is usually only necessary with functions that issue system calls that cause the process to exit, or to transition to a new codebase (such as execve).