[Bug c++/124584] [15/16/17 Regression] Destructor of tuple-protocol structured binding from co_await skipped at -O1+

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124584

--- Comment #9 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-16 branch has been updated by Jason Merrill
<jason@gcc.gnu.org>:

https://gcc.gnu.org/g:0eaa676f6e15fab1a566fe410d23aaf83e05c36f

commit r16-9218-g0eaa676f6e15fab1a566fe410d23aaf83e05c36f
Author: Jason Merrill <jason@redhat.com>
Date:   Thu Jul 2 17:54:22 2026 -0400

    c++: co_await and structured bindings [PR124584]

    Here the internal guard variables that control whether to clean up the
    structured binding variables were not living across the call to co_await
    because they weren't promoted into the coroutine frame.  The underlying
    problem is using a TARGET_EXPR, which lives only for the full-expression,
to
    hold a value that needs to live as long as the variable itself.  So
    get_temp_regvar seems like a better fit.  We also need to manually pushdecl
    the guard variable so that it's visible to register_local_var_uses.

    It might be better to use the wrap_temporary_cleanups mechanism for the
main
    variable, as we do for normal variables.  But let's go with the simple fix
    for now.

            PR c++/124584

    gcc/cp/ChangeLog:

            * decl.cc (cp_finish_decl): Use get_temp_regvar for decomp guards.

    gcc/testsuite/ChangeLog:

            * g++.dg/coroutines/torture/tuple-decomp-pr124584.C: New test.

    (cherry picked from commit a085455306ec4aa15a11efacd994968bf951f7b6)