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* [Bug c++/95517] New: [coroutines] suggested warning when co_return and return_void() are missing
@ 2020-06-03 21:13 bruck.michael at gmail dot com
2020-06-04 19:22 ` [Bug c++/95517] " iains at gcc dot gnu.org
` (6 more replies)
0 siblings, 7 replies; 8+ messages in thread
From: bruck.michael at gmail dot com @ 2020-06-03 21:13 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95517
Bug ID: 95517
Summary: [coroutines] suggested warning when co_return and
return_void() are missing
Product: gcc
Version: 10.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: bruck.michael at gmail dot com
Target Milestone: ---
[stmt.return.coroutine]
"3 If p.return_void() is a valid expression, flowing off the end of a coroutine
is equivalent to a co_return with no operand; otherwise flowing off the end of
a coroutine results in undefined behavior."
It would be useful to diagnose this.
Example code that includes the undefined behavior and produces no warnings with
-Wall -Wextra:
---
#include <coroutine>
struct dummy
{
struct promise_type
{
dummy get_return_object() const noexcept { return {}; }
std::suspend_never initial_suspend() const noexcept { return {}; }
std::suspend_never final_suspend() const noexcept { return {}; }
//void return_void() const noexcept {}
void unhandled_exception() const noexcept {}
};
int i; // work around #95516
};
dummy foo()
{
co_await std::suspend_never{};
//co_return;
}
int main()
{
foo();
}
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug c++/95517] [coroutines] suggested warning when co_return and return_void() are missing
2020-06-03 21:13 [Bug c++/95517] New: [coroutines] suggested warning when co_return and return_void() are missing bruck.michael at gmail dot com
@ 2020-06-04 19:22 ` iains at gcc dot gnu.org
2021-04-27 11:38 ` jakub at gcc dot gnu.org
` (5 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: iains at gcc dot gnu.org @ 2020-06-04 19:22 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95517
Iain Sandoe <iains at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Ever confirmed|0 |1
Target Milestone|--- |11.0
Last reconfirmed| |2020-06-04
Severity|normal |enhancement
Assignee|unassigned at gcc dot gnu.org |iains at gcc dot gnu.org
Status|UNCONFIRMED |ASSIGNED
--- Comment #1 from Iain Sandoe <iains at gcc dot gnu.org> ---
Generally, it's not required to diagnose UB, however I think we can do better
with the co_return/return stuff and have some ideas in mind already. So, yes
this a good idea,
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug c++/95517] [coroutines] suggested warning when co_return and return_void() are missing
2020-06-03 21:13 [Bug c++/95517] New: [coroutines] suggested warning when co_return and return_void() are missing bruck.michael at gmail dot com
2020-06-04 19:22 ` [Bug c++/95517] " iains at gcc dot gnu.org
@ 2021-04-27 11:38 ` jakub at gcc dot gnu.org
2021-07-28 7:04 ` rguenth at gcc dot gnu.org
` (4 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: jakub at gcc dot gnu.org @ 2021-04-27 11:38 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95517
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|11.0 |11.2
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 11.1 has been released, retargeting bugs to GCC 11.2.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug c++/95517] [coroutines] suggested warning when co_return and return_void() are missing
2020-06-03 21:13 [Bug c++/95517] New: [coroutines] suggested warning when co_return and return_void() are missing bruck.michael at gmail dot com
2020-06-04 19:22 ` [Bug c++/95517] " iains at gcc dot gnu.org
2021-04-27 11:38 ` jakub at gcc dot gnu.org
@ 2021-07-28 7:04 ` rguenth at gcc dot gnu.org
2021-08-10 3:17 ` wei_mj at 139 dot com
` (3 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: rguenth at gcc dot gnu.org @ 2021-07-28 7:04 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95517
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|11.2 |11.3
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 11.2 is being released, retargeting bugs to GCC 11.3
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug c++/95517] [coroutines] suggested warning when co_return and return_void() are missing
2020-06-03 21:13 [Bug c++/95517] New: [coroutines] suggested warning when co_return and return_void() are missing bruck.michael at gmail dot com
` (2 preceding siblings ...)
2021-07-28 7:04 ` rguenth at gcc dot gnu.org
@ 2021-08-10 3:17 ` wei_mj at 139 dot com
2021-08-10 5:32 ` iains at gcc dot gnu.org
` (2 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: wei_mj at 139 dot com @ 2021-08-10 3:17 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95517
mengjun wei <wei_mj at 139 dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |wei_mj at 139 dot com
--- Comment #4 from mengjun wei <wei_mj at 139 dot com> ---
GCC 11.2 no longer allow return_value and return_void be both defined, may this
restriction be removed? This makes the co_return statement necessary:
CTask workflow_work(CTaskScheduler::RawPtr scheduler,
co_comm_ctx::co_comm_workflow* workflow, const char* buf, int len)
{
co_comm_resp_impl::ptr response(new co_comm_resp_impl);
co_await co_comm_ctx::short_req_task::create(workflow, 1, buf, len,
response);
co_await co_comm_ctx::short_req_task::create(workflow, 2, buf, len,
response);
co_await co_comm_ctx::resp_task::create(workflow,
response->result.c_str(), response->result.length());
co_return 0;
}
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug c++/95517] [coroutines] suggested warning when co_return and return_void() are missing
2020-06-03 21:13 [Bug c++/95517] New: [coroutines] suggested warning when co_return and return_void() are missing bruck.michael at gmail dot com
` (3 preceding siblings ...)
2021-08-10 3:17 ` wei_mj at 139 dot com
@ 2021-08-10 5:32 ` iains at gcc dot gnu.org
2022-04-21 7:48 ` rguenth at gcc dot gnu.org
2023-05-29 10:02 ` jakub at gcc dot gnu.org
6 siblings, 0 replies; 8+ messages in thread
From: iains at gcc dot gnu.org @ 2021-08-10 5:32 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95517
--- Comment #5 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to mengjun wei from comment #4)
> GCC 11.2 no longer allow return_value and return_void be both defined, may
> this restriction be removed?
The restriction is part of the C++ standard (for the record, there was
discussion about allowing both to be present, but that was rejected by the
committee).
https://eel.is/c++draft/dcl.fct.def.coroutine#6
So, we cannot remove the restriction.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug c++/95517] [coroutines] suggested warning when co_return and return_void() are missing
2020-06-03 21:13 [Bug c++/95517] New: [coroutines] suggested warning when co_return and return_void() are missing bruck.michael at gmail dot com
` (4 preceding siblings ...)
2021-08-10 5:32 ` iains at gcc dot gnu.org
@ 2022-04-21 7:48 ` rguenth at gcc dot gnu.org
2023-05-29 10:02 ` jakub at gcc dot gnu.org
6 siblings, 0 replies; 8+ messages in thread
From: rguenth at gcc dot gnu.org @ 2022-04-21 7:48 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95517
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|11.3 |11.4
--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 11.3 is being released, retargeting bugs to GCC 11.4.
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug c++/95517] [coroutines] suggested warning when co_return and return_void() are missing
2020-06-03 21:13 [Bug c++/95517] New: [coroutines] suggested warning when co_return and return_void() are missing bruck.michael at gmail dot com
` (5 preceding siblings ...)
2022-04-21 7:48 ` rguenth at gcc dot gnu.org
@ 2023-05-29 10:02 ` jakub at gcc dot gnu.org
6 siblings, 0 replies; 8+ messages in thread
From: jakub at gcc dot gnu.org @ 2023-05-29 10:02 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95517
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|11.4 |11.5
--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 11.4 is being released, retargeting bugs to GCC 11.5.
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2023-05-29 10:02 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
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2020-06-03 21:13 [Bug c++/95517] New: [coroutines] suggested warning when co_return and return_void() are missing bruck.michael at gmail dot com
2020-06-04 19:22 ` [Bug c++/95517] " iains at gcc dot gnu.org
2021-04-27 11:38 ` jakub at gcc dot gnu.org
2021-07-28 7:04 ` rguenth at gcc dot gnu.org
2021-08-10 3:17 ` wei_mj at 139 dot com
2021-08-10 5:32 ` iains at gcc dot gnu.org
2022-04-21 7:48 ` rguenth at gcc dot gnu.org
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