[Bug middle-end/121159] musttail gives bogus volatile function error message

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121159

--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Ah, in PR119483 I've only handled the case where the function is not declared
[[noreturn]] but is implicitly turned into [[noreturn]] because it is
determined to never return.
We need another one liner to make explicit [[noreturn]] to work.

[[gnu::noinline, gnu::noclone]] int
foo (void)
{
  asm volatile ("" : : : "memory");
  for (;;)
    ;
  return 42;
}

int
bar (void)
{
  [[gnu::musttail]] return foo ();
}

[[noreturn, gnu::noipa]] void
baz (void)
{
  for (;;)
    ;
}

void
qux (void)
{
  [[gnu::musttail]] return baz ();
}