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From: "vsolontsov at volanttrading dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/100850] New: [coroutine] Wrong addresses of variables
 captured by reference into lambda co-routines.
Date: Tue, 01 Jun 2021 08:37:19 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D100850

            Bug ID: 100850
           Summary: [coroutine] Wrong addresses of variables captured by
                    reference into lambda co-routines.
           Product: gcc
           Version: 11.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vsolontsov at volanttrading dot com
  Target Milestone: ---

In a code like this:
```
    int i;

    auto coro =3D [&i, pi =3D &i](int& i1) -> task {
//        co_await std::suspend_always{};
        std::cout << "&i=3D=3D&i1: " << std::boolalpha << (&i =3D=3D &i1) <=
< std::endl;
        std::cout << "&i=3D=3Dpi: " << std::boolalpha << (&i =3D=3D pi) << =
std::endl;
        std::cout << "&i1=3D=3Dpi: " << std::boolalpha << (&i1 =3D=3D pi) <=
< std::endl;
        co_return;
    }(i);
```
If the captured variables are not used until the very first suspension, the
addresses appear to be wrong. https://godbolt.org/z/c945q893j
If the `task::initial_suspend()` returns `suspend_never` and the `co_await`=
 in
the co-routine is commented out, all good. Otherwise, if there's a suspensi=
on
before the first use of the variables, the address get screwed.=