https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105104
Iain Sandoe <iains at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed|2022-03-30 00:00:00 |2022-4-18
CC| |iains at gcc dot gnu.org,
| |jakub at gcc dot gnu.org
Status|WAITING |NEW
Keywords| |ice-on-valid-code
--- Comment #6 from Iain Sandoe <iains at gcc dot gnu.org> ---
Initial analysis - perhaps some issue with constexpr processing:
When we have a void await_return() in the final_awaiter class:
final.suspend:
frame_ptr->_Coro_resume_fn = 0B;
{
struct final_awaiter Fs [value-expr: frame_ptr->Fs_1_2];
frame_ptr->_Coro_resume_index = 4;
_15 = &frame_ptr->_Coro_self_handle;
D.9844 = std::__n4861::coroutine_handle<return_object::promise_type>::operator
std::__n4861::coroutine_handle<void> (_15);
return_object::promise_type::final_awaiter::await_suspend (D.9844);
D.9768 = .CO_YIELD (4, 1, &resume.4, &destroy.4, frame_ptr);
retval.2 = D.9768;
switch (retval.2) <default: <D.9771>, case 0: <D.9769>, case 1: <D.9770>>
<D.9769>:
.CO_SUSPN (&actor.suspend.ret);
<D.9770>:
goto resume.4;
<D.9771>:
goto destroy.4;
destroy.4:
goto coro.delete.promise;
resume.4:
return_object::promise_type::final_awaiter::await_resume ();
}
when the await_resume() function is made to return an int.
final.suspend:
frame_ptr->_Coro_resume_fn = 0B;
{
<snip>
destroy.4:
goto coro.delete.promise;
resume.4:
}
So we have a dangling label at the end of that scope (which then gives rise to
the crash).
* If I remove the 'contexpr' from the await_resume() function, then it all
works as expected.
* AFAICT, the content is correct in "expand_one_await_expression()".
* Altering the coroutines code to cast the result of the await_resume() to void
makes no difference.
