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From: Rebecca Ribas <beky.ribas@gmail.com>
To: gcc@gcc.gnu.org
Subject: Confused about coroutine behavior
Date: Fri, 26 Aug 2022 01:55:20 -0400	[thread overview]
Message-ID: <CALoH1AMm4muBJZGYK05oBt57i_aE2gxAfy5AYbByaBnsXh6WOg@mail.gmail.com> (raw)

Hi gcc list,

I'm learning c++ coroutines but I ran into a behavior that I can't make
sense of.

Here is the godbolt link: https://godbolt.org/z/rdPo8ceKP

In some cases, it appears that temporaries are incorrectly freed, the code
shows test1 and test2 that works as expected, but test3 raises a "used
after free" error from address sanitizer that doesn't make sense to me.

I'm aware that there are some potential caveats with passing references to
a coroutine, so I'm possibly missing some subtle detail. But it looks like
it might be a gcc bug since the same doesn't happen with clang.

I tested a few different versions of g++ available on ubuntu and godbolt
but got the same result.

The compilations flags I used were: -ggdb3 -Og -std=c++20 -Wall -Wextra
-Werror -D_GLIBCXX_DEBUG -fsanitize=address

Cheers!

WARNING: multiple messages have this Message-ID

From: Rebecca Ribas <beky.ribas@gmail.com>
To: gcc@gcc.gnu.org
Subject: Confused about coroutine behavior
Date: Fri, 26 Aug 2022 01:55:20 -0400	[thread overview]
Message-ID: <CALoH1AMm4muBJZGYK05oBt57i_aE2gxAfy5AYbByaBnsXh6WOg@mail.gmail.com> (raw)
Message-ID: <20220826055520.wV5Y8fRYfQpwonH0x14eMmeFqu2i7MY8Lpdyxq4kdIw@z> (raw)

[-- Attachment #1: Type: text/plain, Size: 814 bytes --]

Hi gcc list,

I'm learning c++ coroutines but I ran into a behavior that I can't make
sense of.

Here is the godbolt link: https://godbolt.org/z/rdPo8ceKP

In some cases, it appears that temporaries are incorrectly freed, the code
shows test1 and test2 that works as expected, but test3 raises a "used
after free" error from address sanitizer that doesn't make sense to me.

I'm aware that there are some potential caveats with passing references to
a coroutine, so I'm possibly missing some subtle detail. But it looks like
it might be a gcc bug since the same doesn't happen with clang.

I tested a few different versions of g++ available on ubuntu and godbolt
but got the same result.

The compilations flags I used were: -ggdb3 -Og -std=c++20 -Wall -Wextra
-Werror -D_GLIBCXX_DEBUG -fsanitize=address

Cheers!

             reply	other threads:[~2022-08-26  5:55 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-26  5:55 Rebecca Ribas [this message]
2022-08-26  5:55 ` Rebecca Ribas
2022-08-26  9:12 ` Jonathan Wakely

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