This definition of function 'h' should produce an error:
void g (void) {
}
void h (void) {
return g();
}
[gray book r.6.6.3: "A return statement with an expression can be used only in
functions returning a value"]
This definition of function 'f' should produce an error:
short f (void) {
short a;
if (a)
return 1;
a = 3;
}
[gray book r.6.6.3: "Flowing off the end of a function is … illegal in a
value-returning function"]