[Bug c++/106111] -Wc++20-compat doesn't warn about using `requires` as an identifier

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106111

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Marek Polacek <mpolacek@gcc.gnu.org>:

https://gcc.gnu.org/g:2ea6c59349793761b9c00f75ef281ac413566b2f

commit r13-1394-g2ea6c59349793761b9c00f75ef281ac413566b2f
Author: Marek Polacek <polacek@redhat.com>
Date:   Tue Jun 28 18:59:19 2022 -0400

    c++: warn about using keywords as identifiers [PR106111]

    In C++03, -Wc++11-compat should warn about

      int constexpr;

    since 'constexpr' is a keyword in C++11.  Jonathan reports that
    we don't emit a similar warning for 'alignas' or 'alignof', and,
    as I found out, 'thread_local'.

    Similarly, we don't warn for most C++20 keywords.  That happens
    because RID_LAST_CXX20 hasn't been updated in a while.

            PR c++/106111

    gcc/c-family/ChangeLog:

            * c-common.h (enum rid): Update RID_LAST_CXX20.

    gcc/cp/ChangeLog:

            * parser.cc (cp_lexer_get_preprocessor_token): Also warn about
            RID_ALIGNOF, RID_ALIGNAS, RID_THREAD.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp0x/keywords1.C: New test.
            * g++.dg/cpp2a/keywords1.C: New test.