[Bug c++/109923] Template friend function defined in a template class becomes a friend of all instantiations, not one

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109923

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Patrick Palka <ppa...@gcc.gnu.org>:

https://gcc.gnu.org/g:38af81df6aac11d49f9378d1c628ccc3c815c3ff

commit r14-1519-g38af81df6aac11d49f9378d1c628ccc3c815c3ff
Author: Patrick Palka <ppa...@redhat.com>
Date:   Sat Jun 3 09:26:43 2023 -0400

    c++: is_specialization_of_friend confusion [PR109923]

    The check for a non-template member function of a class template in
    is_specialization_of_friend is overbroad, and accidentally holds for a
    non-template hidden friend too, which for the testcase below causes the
    predicate to bogusly return true for

      decl = void non_templ_friend(A<int>, A<void>)
      friend_decl = void non_templ_friend(A<void>, A<void>)

    This patch refines the check appropriately.

            PR c++/109923

    gcc/cp/ChangeLog:

            * pt.cc (is_specialization_of_friend): Fix overbroad check for
            a non-template member function of a class template.

    gcc/testsuite/ChangeLog:

            * g++.dg/template/friend79.C: New test.