[Bug c++/113332] [12/13/14 regression] checking ICE when building fcitx-5.1.6

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113332

--- Comment #5 from GCC 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:9bc6b23d11697545e8a951ccd60691b1e58b98c2

commit r14-8981-g9bc6b23d11697545e8a951ccd60691b1e58b98c2
Author: Patrick Palka <ppalka@redhat.com>
Date:   Wed Feb 14 10:20:31 2024 -0500

    c++: synthesized_method_walk context independence [PR113908]

    In the second testcase below, during ahead of time checking of the
    non-dependent new-expr we synthesize B's copy ctor, which we expect to
    get defined as deleted since A's copy ctor is inaccessible.  But during
    access checking thereof, enforce_access incorrectly decides to defer it
    since we're in a template context according to current_template_parms
    (before r14-557 it checked processing_template_decl which got cleared
    from implicitly_declare_fn), which leads to the access check leaking out
    to the template context that triggered the synthesization, and B's copy
    ctor getting declared as non-deleted.

    This patch fixes this by using maybe_push_to_top_level to clear the
    context (including current_template_parms) before proceeding with the
    synthesization.  We could do this from implicitly_declare_fn, but it's
    better to do it more generally from synthesized_method_walk for sake of
    its other callers.

    This turns out to fix PR113332 as well: there the lambda context
    triggering synthesization was causing maybe_dummy_object to misbehave,
    but now synthesization is sufficiently context-independent.

            PR c++/113908
            PR c++/113332

    gcc/cp/ChangeLog:

            * method.cc (synthesized_method_walk): Use maybe_push_to_top_level.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp0x/lambda/lambda-nsdmi11.C: New test.
            * g++.dg/template/non-dependent31.C: New test.

    Reviewed-by: Jason Merrill <jason@redhat.com>