> This is a corner of C I'm not familiar with, but does the standard say anything about functions that never return? A few things, but not a lot of detail. >

> This is a corner of C I'm not familiar with, but does the standard say anything about functions that never return? A few things, but not a lot of detail. > A function declared with a_Noreturn function specifier shall not return to its caller 6.7.4-8 It is recommended, but not enforced, that the implementation warns if this might not be the case. > The implementation should produce a diagnostic message for a function declared with a_Noreturn function specifier that appears to be capable of returning to its caller 6.7.4-9 They do provide some example code that explicitly says that non-returning functions, that are marked as such, need to be explicit that they don't return. (As C implicitly attempts to return if given the opportunity). Not doing so is Undefined Behaviour. _Noreturn void f () { abort(); //ok } _Noreturn void g (int i) { //causes undefined behavior if i<=0 if (i > 0) abort(); } So a compiler should be able to assume that a _Noreturn function either loops forever or terminates. Anything else would appear to be UB. The compiler can't assume that a function always returns.