[Bug c++/100700] -Wreturn-type has many false positives

["msebor at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100700

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |msebor at gcc dot gnu.org
           Severity|normal                      |enhancement

--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> ---
[Please include the full command line and the full compiler output in bug
reports (as requested in https://gcc.gnu.org/bugs/#need). Links to third party
sites are not a substitute (they can go away and the compiler versions they use
can change).]

$ cat pr100700.c && gcc -S -xc++ pr100700.c

int f(unsigned i) {
  if (i < unsigned(-1)) return i;
}

enum E { A, B };

int h (enum E e) {
  switch (e) {
  case A: return 0;
  case B: return 0;
  }
}
pr100700.c: In function ‘int f(unsigned int)’:
pr100700.c:4:1: warning: control reaches end of non-void function
[-Wreturn-type]
    4 | }
      | ^
pr100700.c: In function ‘int h(E)’:
pr100700.c:13:1: warning: control reaches end of non-void function
[-Wreturn-type]
   13 | }
      | ^

In both examples the warning is strictly correct: in a call to f(-1) the
function falls off the end, and ditto in a call to h ((enum E)2).  I could see
value in relaxing the warning for the enum case and issuing it only under some
stricter setting (say with -Wextra or under a new level), similarly to
-Wswitch-default.  I think there already is a request along these lines.