[Bug c++/93805] [8/9/10 Regression] A suspicious -Werror=noexcept warning since r8-2461-g9fb82e652cee118b

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93805

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Patrick Palka <ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:1f6c1c82eb5001a844b5ac535f6aba4a3257031f

commit r10-7345-g1f6c1c82eb5001a844b5ac535f6aba4a3257031f
Author: Patrick Palka <ppalka@redhat.com>
Date:   Fri Mar 13 14:30:39 2020 -0400

    c++: Avoid a suspicious -Wnoexcept warning [PR93805]

    In this PR we're emitting -Wnoexcept warnings about potentially-throwing
NSDMIs
    when computing the noexcept specification of a class's defaulted default
    constructor.  Although these warnings are in some sense valid, this patch
takes
    the route of suppressing them, because:

      1. the warning message is confusing in its current form;
      2. warning for 'struct C { B b = B(); };' but not for 'struct C { B b;
};'
         is inconsistent; and
      3. emitting a warning here arguably doesn't fall under the umbrella of
         -Wnoexcept, whose documentation says it warns only when a
         noexcept-expression evaluates to false, but there are no
         noexcept-expressions here.

    gcc/cp/ChangeLog:

            PR c++/93805
            * except.c (maybe_noexcept_warning): Add TODO comment.
            * method.c (walk_field_subobs): Pass tf_none to expr_noexcept_p.

    gcc/testsuite/ChangeLog:

            PR c++/93805
            * g++.dg/warn/Wnoexcept2.C: New test.